Treatise on Poisons / In relation to medical jurisprudence, physiology, and the practice of physic

by Sir Robert Christison

CONTENTS.

PART FIRST.—Of General Poisoning.
			PAGE
CHAP. I.		Of the Physiological Action of Poisons	[9]
	Section 1.	Of their Mode of Action	[9]
		Of the Discovery of Poisons in the Blood	[21]
	Section 2.	Of the Causes which modify their Action	[27]
		Application of the preceding observations to the Treatment of Poisoning	[36]
CHAP. II.		Of the Evidence of General Poisoning	[39]
	Section 1.	Of the Evidence from Symptoms	[42]
		Characters of the Symptoms of Poisoning	[42]
		Characters of the Symptoms of Natural Disease	[46]
	Section 2.	Of the Evidence from Morbid Appearances	[51]
	Section 3.	Of the Evidence from Chemical Analysis	[54]
		Causes which remove Poisons beyond the reach of analysis	[55]
		Chemical Evidence not always indispensable to the proof of Poisoning	[59]
	Section 4.	Evidence from Experiments on Animals	[62]
		With suspected articles of food or drink	[63]
		With vomited matter or contents of the stomach	[67]
		With the flesh of poisoned animals	[69]
	Section 5.	Moral Evidence	[71]
		Suspicious conduct of prisoner, [73] and [78].—Proof of administration of poison, [73].—Proof of intent, [78].—Proof from simultaneous illness of several people, [80].—Proof from death-bed declaration	[83]
CHAP. III.		Of Imaginary, Pretended, and Imputed Poisoning	[85]
PART II.—Of Individual Poisons.
CHAP. I.		Classification of Poisons	[90]
CHAP. II.		Class First. Of Irritant Poisons generally	[92]
	Section 1.	Of the Symptoms of Irritant Poisons compared with those of Natural Disease	[93]
	Section 2.	Of the Morbid Appearances of Irritant Poisoning compared with those of natural disease	[110]
CHAP. III.		Mineral Acids	[121]
	Section 1.	Sulphuric Acid	[123]
		Tests, [123], Action, [128], Morbid Appearances, [135], Treatment,	[140]
	Section 2.	Nitric Acid	[142]
	Section 3.	Hydrochloric Acid	[146]
CHAP. IV.		Phosphorus. Sulphur. Chlorine. Iodine. Iodide of Potassium. Bromine	[149]
CHAP. V.		Acetic Acid	[164]
CHAP. VI.		Oxalic Acid	[167]
	Section 1.	Tests	[168]
	Section 2.	Action and Symptoms in Man	[173]
	Section 3.	Morbid Appearances	[177]
	Section 4.	Treatment	[178]
		Tartaric and Citric Acid	[180]
CHAP. VII.		Fixed Alkalis	[180]
CHAP. VIII.		Nitre	[187]
CHAP. IX.		Alkaline and Earthy Chlorides	[191]
CHAP. X.		Lime	[192]
CHAP. XI.		Ammonia and its salts	[193]
CHAP. XII.		Alkaline Sulphurets	[196]
CHAP. XIII.		Arsenic	[197]
	Section 1.	Tests for its compounds	[198]
		Fly-powder	[199]
		Oxide of Arsenic	[200]
		Tests in its solid state	[203]
		—— a pure solution	[206]
		—— when in organic mixtures	[215]
		Arsenite of Copper	[223]
		—— of Potass	[223]
		Arseniate of Potass	[224]
		Sulphurets of Arsenic	[224]
		Arseniuretted-hydrogen	[227]
	Section 2.	Action and Symptoms in Man	[227]
		Mode of Action	[227]
		Symptoms in ordinary cases	[234]
		—— very short cases	[241]
		—— tedious cases	[244]
		Effects through other channels besides the Stomach	[251]
		Force of the evidence from Symptoms	[259]
	Section 3.	Morbid Appearances	[262]
	Section 4.	Treatment	[283]
CHAP. XIV.		Mercury	[289]
	Section 1.	Tests for its preparations	[289]
		Red Precipitate	[290]
		Cinnabar	[290]
		Turbith Mineral	[290]
		Calomel	[291]
		Corrosive Sublimate	[291]
		—— Tests in the solid state	[292]
		—— solution	[292]
		—— organic mixtures	[296]
		Bicyanide of Mercury	[303]
		Nitrates of Mercury	[303]
	Section 2.	Mode of Action and Symptoms	[303]
		Mode of Action	[303]
		Symptoms of Corrosive Poisoning	[310]
		Symptoms of Irritation and Erethysm combined	[314]
		Symptoms of Erethysm and Mercurial Tremor	[316]
	Section 2.	Action on different Tissues and in different Chemical forms	[327]
		Force of evidence from Symptoms	[336]
	Section 3.	Morbid Appearances	[337]
	Section 4.	Treatment	[342]
CHAP. XV.		Copper	[345]
	Section 1.	Tests for its Compounds	[346]
	Section 2.	Action and Symptoms	[358]
	Section 3.	Morbid Appearances	[364]
	Section 4.	Treatment	[365]
CHAP. XVI.		Antimony	[367]
	Section 1.	Tests for its Compounds	[367]
	Section 2.	Action and Symptoms	[371]
	Section 3.	Morbid Appearances	[376]
	Section 4.	Treatment	[377]
CHAP. XVII.		Tin, [379]—Silver, [380]—Gold, [383]—Bismuth, [383]—Chrome, [385]—Zinc, [386]—Iron, [391]—Other rarer metals, [395]	[378]
CHAP. XVIII.		Lead	[396]
	Section 1.	Chemical History, and Tests for its Compounds	[396]
		Action of Water on Lead	[399]
		Action of Acidulous Fluids on Lead	[416]
		Process for Lead in Organic Fluids	[423]
	Section 2.	Action and Symptoms in Man	[424]
		Tradesmen who are apt to suffer from Lead	[436]
	Section 3.	Morbid Appearances	[439]
	Section 4.	Treatment, and Precautions for Workmen	[441]
CHAP. XIX.		Baryta	[446]
CHAP. XX.		Vegetable Acrids, Euphorbia, Castor-oil seed, Physic-nut, Bitter Cassava, Manchineel, Croton, Bryony, Colocynth, Elaterium, Ranunculus, Anemone, Caltha, Clematis, Trollius, Mezereon, Cuckoo-pint, Gamboge, Daffodil, Jalap, Savin	[451]
CHAP. XXI.		Cantharides	[470]
CHAP. XXII.		Poisonous Fish	[477]
CHAP. XXIII.		Venomous Serpents and Insects	[484]
CHAP. XXIV.		Diseased and Decayed Animal Matter	[487]
CHAP. XXV.		Mechanical Irritants	[501]
		Substances, irritant, in large doses,—Pepper, Epsom Salt, Alum, Cream of Tartar, Sulphate of Potass, Common Salt, &c.	[506]
CHAP. XXVI.		Class II. Of Narcotic Poisons, [510]—of Narcotic Poisoning generally, and the distinction between it and natural disease, [511]	[510]
CHAP. XXVII.		Opium	[530]
	Section 1.	Chemical History and Tests	[530]
	Section 2.	Action and Symptoms	[539]
		Action of Morphia and Narcotine	[557]
	Section 3.	Morbid Appearances	[562]
	Section 4.	Treatment	[566]
CHAP. XXVIII.		Hyoscyamus, Lactuca, and Solanum	[571]
CHAP. XXIX.		Hydrocyanic Acid	[577]
	Section 1.	Tests	[578]
	Section 2.	Action and Symptoms	[582]
	Section 3.	Morbid Appearances	[593]
	Section 4.	Treatment	[596]
		Of the Vegetable Substances which contain Hydrocyanic Acid, [600]—Bitter Almond, [601]—Cherry-laurel, [605]—Peach, [608]—Cluster-cherry, [608]—Mountain-ash,	[608]
CHAP. XXX.		Carbazotic Acid	[610]
CHAP. XXXI.		Poisonous Gases	[611]
		What Gases are Poisonous	[612]
		Effects on Man of Nitric Oxide Gas, [615]—Chlorine, [616]—Ammonia, [617]—Hydrochloric Acid, [617]—Hydrosulphuric Acid, [617]—Carburetted hydrogen, [622]—Carbonic Acid, [624]—Carbonic Oxide, [634]—Nitrous Oxide, [635]—Cyanogen, [636]—Oxygen,	[636]
CHAP. XXXII.		Class III. Narcotico-Acrid Poisons	[637]
CHAP. XXXIII.		Nightshade, [639]—Thorn-Apple, [644]—Tobacco, [647]	[639]
CHAP. XXXIV.		Hemlock, [653]—Water-hemlock, [657]—Hemlock Dropwort, [658]—Fool’s Parsley, [661]	[653]
CHAP. XXXV.		Monkshood, [662]—Black Hellebore, [670]	[662]
CHAP. XXXVI.		Squill, [671]—White Hellebore and Cevadilla, [672]—Meadow-Saffron, [674]—Foxglove, [678]—Rue, [681]—Ipecacuan, [682]	[671]
CHAP. XXXVII.		Strychnia, [683]—Nux Vomica, [686]—St. Ignatius’ Bean, [691]—False Angustura, [692]	[682]
CHAP. XXXVIII.		Camphor, [694]—Cocculus Indicus, [696]—Upas Antiar, [698]—Coriaria myrtifolia, [698]—Yew, [699]	[694]
CHAP. XXXIX.		Poisonous Fungi, [700]—wholesome and poisonous kinds, [701]—qualities how modified, [701]—poisonous principles of, [704]—effects on man, [704]—Poisonous Mosses, [710]	[700]
CHAP. XL.		Poisonous Grain, [710]—Spurred rye, [711]—Spurred maize, [718]—rust of wheat, [719]—unripe grain, [719]—Darnel-grass, [721]—Leguminous seeds, [722]	[710]
CHAP. XLI.		Alcohol, [725]—symptoms in man, [725]—morbid appearances, [731]—treatment, [735]—ether, [736]—Empyreumatic Oils, [736]	[725]
CHAP. XLII.		Compound Poisoning	[740]
Index			[745]
Description of Plate			[755], [756]

PART FIRST.
OF GENERAL POISONING.

CHAPTER I.
ON THE PHYSIOLOGICAL ACTION OF POISONS.

I shall discuss this subject by considering first the mode in which poisons act, and secondly, the causes by which their action is liable to be modified.

Section I.—On the Mode of Action of Poisons.

On attending to the effects which follow the application of a poison to the body, we perceive that they are sometimes confined to the part where it is applied, and at other times extend to distant organs. Hence the action of poisons may be naturally considered as local and remote.

The local effects of poisons are of three kinds. Some decompose chemically or corrode the part to which they are applied. Others, without immediately injuring its organization, inflame or irritate it. Others neither corrode nor irritate, but make a peculiar impression on the sentient extremities of the nerves, unaccompanied by any visible change of structure.

We have examples of local corrosion or chemical decomposition in the effects of the concentrated mineral acids or alkalis on the skin, and in the effects of strong oxalic acid, lunar caustic, or corrosive sublimate on the stomach. In all of these instances the part to which the poison is applied undergoes chemical changes, and the poison itself sometimes undergoes chemical changes also. Thus oxalic acid dissolves the gelatin of the animal textures; and in the instance of corrosive sublimate, the elements of the poison unite with the albumen, fibrin, and other principles of the tissues.

Of local irritation and its various consequences we have many examples, from redness, its slightest, to ulceration and gangrene, its most severe effect. Thus externally, alcohol reddens the skin; cantharides irritates the surface of the true skin and causes vesication; tartar-emetic causes deep-seated inflammation of the true skin and a pustular eruption; the juice of manchineel[^[1]] spreading inflammation of the subcutaneous cellular tissue; arsenic inflammation of all these textures, and also death of the part and subsequent sloughing. Internally, alcohol reddens the stomach, as it does the skin,—but more permanently; while other substances, such as the diluted mineral acids, arsenic, cantharides, euphorbium, and the like, may cause all the phenomena of inflammation in the stomach and intestines, namely, extravasation of blood, effusion of lymph, ulcers, gangrene. Many of these irritants, such as arsenic, are in common speech called corrosives; but they have not any power of causing chemical decomposition: if they produce a breach in the texture of an organ, it is merely through the medium of inflammation and its effects.

Of nervous impressions, without any visible organic change, few well authenticated and unequivocal instances are known. A good example has been mentioned by Sir B. Brodie in the effect of monkshood on the lips when chewed,[^[2]] an effect which I have also often experienced: it causes a sense of numbness and tingling in the lips and tongue, lasting for some hours, and quite unconnected with any affection of the general nervous system. Another instance, first mentioned to me by M. Robiquet, and which I have verified, occurs in the effects of the strong hydrocyanic acid: when this acid is confined in a glass tube with a finger on its open end, the point of the finger becomes benumbed, exactly as from the local action of great cold. These are undoubted instances of a purely nervous local impression on the external surface of the body. The most unequivocal instance I know of a similar impression on internal parts is a fact related by Dr. W. Philip with regard to opium.[^[3]] When this poison was applied to the inner coat of the intestines of a rabbit during life, the muscular contractions of the gut were immediately paralyzed, without the general system being for some time affected. The same effect has been observed by Messrs. Morgan and Addison to follow the application of ticunas to the intestine:[^[4]] an instant and complete suspension of the peristaltic movement took place as soon as it touched the gut. A parallel fact has also been described by Dr. Monro, secundus:[^[5]] when an infusion of opium was injected between the skin and muscles of the leg of a frog, that leg soon became palsied, while the animal was able to leap briskly on the other three. Analogous results have farther been obtained with the prussic acid by M. Coullon.[^[6]] He remarked, that when one hind-leg of a frog was plunged in the acid, it became palsied in thirty-five minutes, while the other hind-leg continued perfectly sensible and irritable. Acetate of lead probably possesses the same property.

These facts are important, because some physiologists have doubted whether any local impressions of a purely nervous nature, unconnected with appreciable organic change, may arise from the action of poisons. Yet the existence of impressions of the kind is essential to the stability of the doctrine of the sympathetic operation of poisons,—that is, of the transmission of their influence from organ to organ along the nerves. Nay, in the instance of many poisons supposed to act in that manner, we must still farther believe in the existence of primary nervous impressions, which are not only unconnected with organic change, but likewise undistinguishable by any local sign whatsoever.

Of the three varieties in the local effects of poisons—corrosion, irritation, and nervous impressions,—the first two may take place in any tissue or organ; for example, they have been observed on the skin, on the mucous membrane of the stomach, intestines, windpipe, air tubes, bladder, and vagina, in the cellular tissue, in the serous membranes of the chest and abdomen, in the muscular fibre. We are not so well acquainted with the nature of local nervous impressions on different tissues; but it is probable that in some textures of the body they are very indistinct.

So much for the local effects of poisons.

On tracing the phenomena which follow more remotely, we observe that the affected part sometimes recovers without any visible change, sometimes undergoes the usual processes consequent on inflammation, sometimes perishes at once and is thrown off; and if the organ is one whose function is necessary to life, death may gradually ensue, in consequence of that function being irrecoverably injured. The purest example of the last train of phenomena is to be seen in the occasional effects of the mineral acids or alkalis: death may take place simply from starvation, because the inner surface of the stomach and intestines is so much injured that a sufficient quantity of nutriment cannot be assimilated.

But death and its antecedents can seldom be accounted for in this way. For symptoms are often witnessed, which bear no direct relation to the local injury: death is generally too rapid to have arisen from the function of the part having been annihilated: and the rapidity of the poisoning is not proportional in different cases to the local injury produced. Even the mineral acids and alkalis seldom kill by impeding or annihilating digestion, because they often prove fatal in a few hours; and among other poisons there are few which ever cause death simply by disturbing the function of the part primarily acted on. Death and the symptoms preceding it arise from an injury of some other organ, to which they are not and cannot be directly applied. We are thus led to consider their remote action.

The term remote is here used in preference to the common phrase general action, because the latter implies an action on the general system or whole body; whereas it appears that an action of such a kind is rare, and that most poisons which have an indirect action exert it on one or more of the important organs only, and not on the general system.

There is not a better instance of the remote action of poisons than oxalic acid. It has been already mentioned that concentrated oxalic acid is a corrosive: yet it never kills by destroying the function of the stomach. Man, as well as the lower animals, will live several days or weeks without nutriment. Now this poison has been known to kill a man in ten minutes, and a dog in three minutes only. Neither does it always induce, when swallowed, symptoms of an injury of the stomach; for death is often preceded by tetanus, or apoplexy, or mortal faintness. Nor is the violence of the poisoning proportional to the extent of the local injury: in fact, death is most rapid under circumstances in which the stomach is least injured, namely, when the acid is considerably diluted.[^[7]]

Let us now proceed to enquire, then, in what way the influence of a poison is conveyed from one organ to another.

Here it will at once be perceived that the conveyance can be accomplished in one of two ways only. Either the local impression passes along the nerves to the organ secondarily affected; or the poison enters the bibulous vessels, mingles with the blood, and passes through the medium of the circulation. In the former way poisons are said to act through sympathy, in the latter, through absorption.

1. On the Action of Poisons through Sympathy. In the infancy of toxicology all poisons were believed to act through sympathy. Since Magendie’s discoveries on venous absorption in 1809, the favourite doctrine has on the other hand been, that most, if not all, act through the medium of the blood. And a recent theory, combining both views, represents that, although many poisons do enter the blood, the operation even of these nevertheless consists of an impression made on the sentient extremities of the nerves of the blood-vessels and conveyed thence along their filaments to the brain or other organs.

The nerves certainly possess the power of conveying from one organ to another various impressions besides those of the external senses. This is shown by many familiar phenomena; and in reference to the present subject, is aptly illustrated by the remote or sympathetic effects of mere mechanical injury and natural disease of the stomach. Acute inflammation of the stomach generally proves fatal long before death can arise from digestion being stopped; and it is accompanied with constitutional symptoms, neither attributable to injury of that function, nor developed in so marked a degree during inflammation in other organs. These symptoms and the rapid death which succeeds them are vaguely imputed to the general system sympathizing with the affected part; but it is more probable that one organ only is thus, at least in the first instance, acted on sympathetically, namely, the heart. The effects of mechanical injuries are still more in point. Wounds of the stomach may prove fatal before inflammation can begin; rupture from over-distension may cause instant death; and in either case without material hemorrhage.

These observations being held in view, it is impossible to doubt, that some organs sympathize with certain impressions made on others at a distance; nor can we imagine any other mode of conveyance for these impressions except along the nerves. The question, then, comes to be what are the impressions that may be so transmitted?

The statements already made will prepare us to expect a sympathetic action in the case of poisons that manifestly injure the structure of the organ to which they are applied. In the instance of the pure corrosives its existence may be presumed from the identity of the phenomena of their remote action with those of natural disease or mechanical injury. It was stated above that the mineral acids when swallowed often prove fatal in a very short space of time; and here, as in mere injury from disease or violence, the symptoms are an imperceptible pulse, fainting, and mortal weakness. Remote organs therefore must be injured; and from the identity of the phenomena with those of idiopathic affections of the stomach, even if there were no other proof, it might be presumed that the primary impression is conveyed along the nerves. We are not restricted, however, to such an argument: The presumptive inference is turned to certainty by the effect of dilution on the activity of these poisons. Dilution materially lessens or even takes away altogether the remote action of the mineral acids. Now dilution facilitates, instead of impeding their absorption: consequently they do not act on remote organs through that channel. There is no other way left by which we can conceive them to act, except by conveyance of the local impression along the nerves.—As to the irritants that are not corrosive, it can hardly be doubted, since they inflame the stomach, that the usual remote effects of inflammation will ensue, namely, a sympathetic injury of distant organs.

But it remains to be considered, whether distant organs may sympathize also with the peculiar local impressions called nervous,—which are not accompanied by any visible derangement of structure. This variety of action by sympathy is the one which has chiefly engaged the attention of toxicologists; and it has been freely resorted to for explaining the effects of many poisons. Nevertheless its existence is doubtful.

The only important arguments in support of the sympathetic action of poisons are, that unequivocal instances exist of local nervous impressions being conveyed to a limited extent along the nerves,—and that the rapidity of the effects of some poisons is so great as to be incompatible with any other medium of action except the nervous system.

In the first place it is maintained, that a limited nervous transmission, that is, the conveyance of a local impression, purely functional in its nature, to parts at a short distance from the texture acted on directly, must occur in some instances,—as, for example, in the action of belladonna in dilating the pupil when applied to the conjunctiva of the eye, and in the effect of opium in allaying deep-seated pain when applied to the integuments over the affected part. It is by no means clear, however, that nervous transmission is in such circumstances the only possible medium of action; and that the phenomena may not as well be owing to the agent being conveyed in substance, by imbibition or absorption, to the parts ultimately acted on. It is not unworthy of remark too, that in the case of hydrocyanic acid,—a poison, which, more perhaps than any other, has been held to act by sympathy, and which produces on the integuments a direct local impression of a peculiar and unequivocal kind,—there is positive evidence of the direct impression not being conveyed along the nerves, even to the most limited distance; for I have not been able to observe the slightest effect beyond the abrupt line on the skin which defines the spot with which the acid had been in contact.

Secondly, it is thought that certain poisons, such as hydrocyanic acid, strychnia, alcohol, conia, and some others, produce their remote effects with a velocity, which is incompatible with any conceivable mode of action except the transmission of a primary local impulse along the nerves, and more especially incompatible with the poison having followed the circuitous route of the circulation to the organs which are affected by it remotely. Thus in regard to the hydrocyanic acid, Sir B. Brodie has stated,[^[8]] that a drop of the essential oil of bitter almonds, which owes its power to this acid, caused convulsions instantly when applied to the tongue of a cat; and that happening once to taste it himself, he had scarcely applied it to his tongue, when he felt a sudden momentary feebleness of his limbs, so that he could scarcely stand. Magendie,[^[9]] speaking of the pure hydrocyanic acid, compares it in point of swiftness of action to the cannon ball or thunderbolt. In the course of certain experiments made not long ago with the diluted acid by Dr. Freer, Mr. Macaulay and others,[^[10]] to decide the true rapidity of this poison, several dogs were brought under its influence in ten, eight, five, and even three seconds; during an experimental inquiry I afterwards undertook for the same purpose,[^[11]] I remarked on one occasion that a rabbit was killed outright in four seconds; and Mr. Taylor has more recently stated, that he has seen the effects induced so quickly in cats, that there was no sensible interval of time between the application of the poison to the tongue and the first signs of poisoning.[^[12]] Strychnia, the active principle of nux-vomica, acts sometimes with a speed little inferior to that of hydrocyanic acid; for Pelletier and Caventou have seen its effects begin in fifteen seconds.[^[13]] Alcohol, according to Sir B. Brodie,[^[14]] also acts on animals with equal celerity; for when he introduced it into the stomach of a rabbit, its effects began when the injection was hardly completed. Conia, the active principle of hemlock, is not less prompt in its operation: when it was injected in the form of muriate into the femoral vein of a dog, I was unable, with my watch in my hand, to observe an appreciable interval between the moment it was injected and that in which the animal died;[^[15]] certainly the interval did not exceed three or at most four seconds.

Facts such as these have been long held adequate to prove that some poisons must act on remote organs by sympathy or transmission of a local impulse along the nerves; and in the last edition of this work they were acknowledged to warrant such a conclusion. It was thought difficult to account for the phenomena on the supposition that the poison was conveyed in substance with the blood to the organ remotely affected by it; for it appeared impossible that, in so short a space of time as elapsed in some of the instances now referred to, the poison could enter the veins of the texture to which it was applied, pass into the right side of the heart, follow the circle of the pulmonary circulation into the left side of the heart, and thence be transmitted by the arterial system to the capillaries of the organ ultimately affected. But the progress of physiological discovery has lately brought the soundness of these views into question. Some years ago Dr. Hering of Stuttgardt showed that the round of the circulation may be accomplished by the blood much more speedily than had been conceived before; for the ferro-cyanide of potassium, injected into the jugular vein of a horse, was discovered by him throughout the venous system at large in the short space of twenty or thirty seconds, and consequently must have passed in that period throughout the whole double circle of the pulmonary and systemic circulation.[^[16]] This discovery at once shook the validity of many, though not all, of the facts which had been previously referred to the agency of nervous transmission on the ground of the celerity with which the effects of poisons are manifested. More recently an attempt has been made by Mr. Blake to prove, that the circulation is so rapid as to admit even of the swiftest cases of poisoning being referred to the agency of absorption. Mr. Blake, who is altogether opposed to the occurrence of nervous transmission in the instance of any poison, has found that ammonia, injected into the jugular vein of a dog, was indicated in its breath in four seconds; and that chloride of barium or nitrate of baryta, introduced into the same vessel, could be detected in the blood of the carotid artery in about sixteen seconds in the horse, in less than seven seconds in the dog, in six seconds in the fowl, and in four seconds in the rabbit.[^[17]] These interesting discoveries, however, will not absolutely destroy the conclusiveness of all the facts quoted above in support of the existence of a sympathetic action. For example they do not shake the validity of those observations, in which it appeared that an interval inappreciable, or barely appreciable, elapsed between the application and action of hydrocyanic acid and of conia. Mr. Blake indeed denies the accuracy of these observations, insisting that, in those he made himself with the most potent poisons, he never failed to witness, before the poison began to act, an interval considerably longer than what had been observed by others, and longer also than what he had found sufficient for the blood to complete the round of the circulation; that, for example, the wourali poison injected into the femoral or jugular vein did not begin to act for twenty seconds, conia and tobacco for fifteen seconds, and extract of nux vomica for twelve seconds; and that hydrocyanic acid dropped on the tongue did not act for eleven seconds if the animal was allowed to inhale its vapour, and not for sixteen seconds, if direct access to the lungs was prevented by making the animal breathe through a tube in the windpipe. But Mr. Blake cannot rid himself thus summarily of the positive facts which stand in his way. Duly weighed, the balance of testimony is in favour of those whose accuracy he impugns. For in the first place, they had not, like him, a theory to build up with their results, but were observing, most of them at least, the simple fact of the celerity of action. Then, their result is an affirmation or positive statement, and his merely a negative one: They may perfectly well have observed what he was not so fortunate as to witness. And lastly, it is not unreasonable to claim for Sir B. Brodie, Dr. Freer, Mr. Macaulay, and Mr. Taylor, all of them practitioners of experience, the faculty of noting time as accurately as Mr. Blake himself. As for my own observations, I feel confident they could not have been made more carefully, and that I had at the moment no preconceived views which the results upheld, but, if anything, rather the reverse.

It is impossible therefore to concede, that Mr. Blake’s inquiries, merely because they are at variance with prior results, apparently not less precise and exact than his own, put an end to the argument which has been drawn, in favour of the existence of a sympathetic action, from the extreme swiftness of the operation of some poisons. At the same time, on a dispassionate view of the whole investigation, it must be granted to be doubtful, whether this argument can be now appealed to in its present shape with the confidence which is desirable. And on the whole, the velocity of the circulation on the one hand, and the celerity of the action of certain poisons on the other, are both of them so very great, and the comparative observation of the time occupied by the two phenomena respectively becomes in consequence so difficult and precarious, that it seems unsafe to found upon such an inquiry a confident deduction on either side of so important a physiological question as the existence or non-existence of an action of poisons by sympathy.

In concluding these statements it is necessary to notice certain positive arguments which have been brought against the doctrine of nervous transmission.

It is alleged to be contrary to nature’s rule to adopt two ways of attaining the same end; and therefore, that, since many poisons undoubtedly act through absorption, it is unphilosophical to hold that others act by sympathy. There seems no sound reason, however, for thus imposing arbitrary limits on the functional powers conferred by nature on the organs of the animal body. And besides, the presumption thus derived is counterbalanced by the equally plausible supposition, that,—since nature has clearly established an action on remote organs through the medium of the nerves in the case of poisons which cause destruction or inflammation of the tissues to which they are applied,—the same medium of action may also exist in the instance of poisons which produce merely a peculiar nervous impression where they are applied.

But it is farther alleged, that poisons of the most energetic action have no effect, when they are applied to a part, the connection of which with the general system is maintained by nerves only. It is true that poisons seem to have no effect whatever when the circulation of the part to which they are applied has been arrested, or when every connecting tissue has been severed except the nerves. Thus Emmert found that the wourali poison does not act on an animal when introduced into a limb connected with the body by nerves alone.[^[18]] And I have ascertained that in the same circumstances no effect is produced on the dog by pure hydrocyanic acid dropped into the cellular tissue of the paw. But it cannot be inferred absolutely from these facts, that the wourali poison and hydrocyanic acid do not act through sympathy; because it has been urged that the integrity of the functions of the sentient extremities of the nerves, more especially their capability of receiving those nervous impressions which are held to be communicated backwards along their course, may be interrupted by arresting the circulation of the part. Still, as the function of sensation is maintained for some time in a severed limb connected with the trunk by nerves only, there is a probability, that all other functions of the nerves must be retained for a time also. And the presumption thus arising is strengthened by an imperfect experiment performed by Mr. Blake, which tends to show, although it does not absolutely prove, that a poison, introduced into the severed limb whose nervous connection with the trunk is entire, will not act, even if the blood be allowed to enter the limb by its artery and to escape from a wound in its vein, so that local circulation is in some measure maintained, without the blood returning to the trunk and general system.[^[19]]

On considering impartially all the facts that have been adduced in this inquiry, an impression must be felt that the doctrine of the sympathetic action of those poisons which produce merely a nervous local impression is insecurely founded. But an experimentum crucis is still wanted to decide the question.

2. Of the Action of Poisons through Absorption.—If doubts may be entertained whether poisons ever act by the transmission of local impulses, from the part to which they are applied, along the nerves to the organ upon which they act, no reasonable doubt can be entertained that many poisons act through the medium of absorption into the blood.

Poisons are believed to act through the blood for the following reasons. First, they disappear during life from the shut cavities or other situations into which they have been introduced; that is, they are absorbed. Several clear examples to this effect have been related by Dr. Coindet and myself in our paper on oxalic acid. In one experiment four ounces of a solution of oxalic acid were injected into the peritoneal sac of a cat, and killed it in fourteen minutes; yet, on opening the animal, although none of the fluid had escaped by the wound, we found scarcely a drachm remaining.[^[20]] In recent times Professor Orfila has proved that various poisons, such as arsenic, tartar-emetic, and acetate of lead, disappear in part or wholly from wounds into which they had been introduced.[^[21]] Next, many poisons act with unimpaired rapidity, when the nerves supplying the part to which they are applied have been previously divided, or even when the part is attached to the body by arteries and veins only. Dr. Monro, secundus, proved this in regard to opium;[^[22]] and the same fact has been since extended by Sir B. Brodie and Professor Emmert to wourali,[^[23]] by Magendie to nux vomica,[^[24]] by Coullon to hydrocyanic acid,[^[25]] by Charret to opium,[^[26]] and by Dr. Coindet and myself to diluted oxalic acid.[^[27]] Magendie’s experiment was the most precise of all: for, besides the communication with the poisoned part being kept up by a vein and an artery only, these vessels were also severed and reconnected by two quills. Farther, many poisons will not act when they are applied to a part of which the circulation has been arrested, even although all its other connections with the body have been left entire. This has been shown distinctly by Emmert in regard to the hydrocyanic acid; which, when introduced into the hind-leg of an animal after the abdominal aorta has been tied, produces no effect till the ligature be removed, but then acts with rapidity.[^[28]] An experiment of a similar nature performed by Mr. Blake with the wourali poison yielded the same result.[^[29]] Again, many poisons act with a force proportional to the absorbing power of the texture with which they are placed in contact. This is the criterion which has been commonly resorted to for discovering whether a poison acts through the medium of the blood. It is applicable, however, only when the poison acts sensibly in small doses; for those which act but in large doses cannot be applied in the same space of time over equal surfaces of different textures. The difference in the absorbing power of the different tissues has been well ascertained in respect to a few of them only. The most rapid channel of absorption is by a wound, or by immediate injection into a vein; the surface of the serous membranes is a less rapid medium, and the mucous membrane of the alimentary canal is still less rapid. Now it is proved of many poisons that, when applied in similar circumstances to these several parts or tissues, their activity is proportional to the order now laid down. Lastly, it has been proved of nux-vomica, that if the extract be thrust into the paw of an animal after a ligature has been tightened round the leg so as to stop the venous, but not the arterial circulation of the limb, blood drawn from an orifice in a vein between the wound and the ligature, and transfused into the vein of another animal, will excite in the latter the usual effects of the poison, so as even to cause death; while, on the contrary, the animal from which the blood has been taken will not be affected at all, if a sufficient quantity be withdrawn before the removal of the ligature. These interesting facts, which are capable of important practical applications, were ascertained by M. Vernière.[^[30]]

On weighing attentively the arguments here brought forward, it seems impossible to doubt, that some poisons are absorbed into the blood before they act, and that their entrance into the blood is not a mere fortuitous antecedent, but a condition essential to their action.

But it is farther held that poisons which act through absorption, do so by being conveyed in substance along with the blood to the part where their action is developed,—that their action eventually depends on the organ, whose functions are thrown into disorder, becoming impregnated with poisoned blood. Now, the arguments detailed above do not absolutely prove this conveyance and impregnation. They show that poisons enter the blood, and act somehow in consequence of entering it; but they do not prove in what manner the action subsequently takes place.

It was at one time indeed supposed that the same facts, which prove their admission into the blood, proved also their transmission in substance to the organs acted on by them. But Dr. Addison and Mr. Morgan have shown that this is not a legitimate conclusion, and that a different theoretical view may be taken of the facts,—namely, that the action may really take place by the poison producing on the sentient extremities of the nerves of the inner membrane of the blood-vessels a peculiar impression which is conveyed through the nerves to the part ultimately affected.[^[31]] They have endeavoured to found this theory upon evidence, that the poison is not carried beyond the venous system; or that, if conveyed farther, it is carried incidentally, and not for the purpose of impregnating the textures of the organ which suffers. The evidence they have brought forward on this head is chiefly the following. 1. Poisons which act on a particular organ at a distance do not act more quickly when introduced into the artery which supplies it, than when introduced into its vein, or even into the principal artery of a distant part of the body.[^[32]] 2. If a poison be introduced into a great vein with a provision for preventing its passage towards the heart, it will act with as great rapidity, as if no obstacle of the kind existed. Thus, if the jugular vein, secured by two temporary ligatures, be divided between them and reconnected by a tube containing wourali, the animal will not be affected more quickly on the removal of both ligatures, than on removing only the ligature farthest from the heart.[^[33]] 3. The arterial blood of a poisoned animal is incapable of affecting another animal. Thus, if the carotid artery and jugular vein of one dog be divided, and both ends of each reciprocally connected by tubes with the divided ends of the corresponding vessels of another dog, and extract of nux-vomica be introduced into a wound in the face of one of them,—the animal directly poisoned alone perishes, and the other remains unharmed to the last.[^[34]]

These are at first view strong arguments against the transmission of poisons with the blood to the organs remotely acted on; and the facts on which they are founded are on the other hand easily explained under the new theory advanced by the authors, that the medium of action is the nerves which supply the inner membrane of the blood-vessels. But their inquiries, however ingenious and plausible, have not stood the test of physiological scrutiny. Their first experimental fact has been contradicted by Mr. Blake; who has found that the wourali poison, which does not begin to act for twenty seconds when injected into a vein, will produce obvious effects in seven seconds only if injected into the aorta through the axillary artery.[^[35]] The second experiment, showing that poison confined in a vein will act although prevented by a ligature from reaching the heart, is held by the opponents of Dr. Addison and Mr. Morgan to be fallacious, in as much as the blood behind the ligature may be carried backwards till it meets with an anastomosing vein and is so carried by a collateral vessel to the heart. To the third experiment it may be objected, that there was, in the mode in which they conducted it, no satisfactory evidence that the reciprocal circulation was kept up by the carotid artery and jugular vein. And this will appear an important objection to every one practically acquainted with experiments of transfusion. For on the one hand it is exceedingly difficult, in such complicated experiments, to prevent coagulation of the blood in one vessel or another, before the connection of all the arteries and veins is established; and on the other, it may be urged, as Mr. Blake has done, that the pressure of the blood in the distal end of the carotid artery in the animal not directly poisoned may be equal, or even superior, to the pressure in the proximal end of the same vessel in the other animal,—so that the blood may not pass from the latter into the former, although it should continue fluid.

In opposition to the theory of Dr. Addison and Mr. Morgan, and in support of the doctrine, that poisons act by being carried in substance with the blood into the tissues of the remote organs on which they act, a variety of important experimental evidence has been brought forward since the publications of the Essay of these gentlemen. In the first place, the concurrent testimony of a great number of recent chemical inquirers establishes undeniably, that poisons absorbed into the veins of the part to which they are applied are to be detected throughout many of the tissues of distant organs. This fact will be enlarged on and illustrated presently. Secondly, on the authority of Mr. Blake, and in contradiction of the experiments of Dr. Addison and Mr. Morgan, it appears that, as already stated, poisons act more quickly when injected into the aorta than into the venous system; a fact which is easily understood, on considering that when injected into the aorta they reach their destination directly, whereas, if injected into a vein they must first arrive at the right side of the heart, and then be transmitted through the circle of the pulmonary circulation before reaching even the aorta. Thirdly, the relative rapidity with which poisons act on different animals follows the ratio of the velocity of the circulation in each. Thus, Mr. Blake found, that in the horse nitrate of baryta is conveyed by the circulation from the jugular vein to the carotid artery in sixteen seconds, and that strychnia injected into the jugular vein begins to act on the nervous system after exactly the same interval: That in the dog chloride of barium passes from the vein to the artery in seven seconds, and extract of nux-vomica begins to act as a poison in twelve seconds: That in the fowl the passage of the blood seems to take place in six seconds, and the nitrate of strychnia to act in six seconds and a half: And that in the rabbit the passage of the blood is effected in four seconds only, and the first signs of the action of strychnia occur in four seconds and a half.[^[36]]

On the whole, then, it may be considered as well established, that probably all, but certainly some, poisons,—of the kind whose topical action does not consist in causing destruction or inflammation of the textures to which they are applied,—produce their remote effects solely by entering the blood, and through its means impregnating the organs which are acted on at a distance. And farther, if this doctrine be admitted as established, it may also be allowed, that many poisons which do cause topically destruction or inflammation, and remotely the usual sympathetic effects of these changes of structure, also possess the power of affecting distant organs through the medium of the blood.

Of the discovery of Poisons in the Blood.—Such being the case, it becomes an object of paramount interest, with reference both to the practice of medical jurisprudence, to inquire whether poisons can be detected in the circulating fluids, or generally in parts of the body remote from the place where they are introduced.

A variety of circumstances long rendered it impossible to determine satisfactorily the question, whether poisons could be detected in the blood, the secretions, and the soft textures of the body. In the first place, we now know that the quantity of the more active poisons, which is required to occasion death, is so small, that, considering the crude methods of analysis formerly trusted to, and the obstacles opposed to the successful application of them by the presence of organic matter, there can be no wonder that chemists, even but a few years ago, could not satisfy themselves whether the objects they were in search of had been detected or not. Then, it was partly known before, and is now fully established, that various poisons are removed beyond the reach of analysis before death, in consequence of passing off with the secretions, particularly the urine. Farther, it seems probable that, of the poisons which act through absorption, several do not remain or at least do not accumulate, in the blood; and that they are not distributed with it throughout the textures indifferently, but are deposited, as absorption goes on, in particular organs, such as the liver,—which it was not much the practice to examine in former investigations. And lastly, some poisons are speedily decomposed on entering the blood: They either cause obvious changes in the constitution of the blood, and themselves undergo alteration likewise; or without the blood becoming appreciably different in its properties from the healthy state, the poison undergoes a rapid change in the molecular affinities of its elements, and so disappears. Of the former course of things distinct illustrations are furnished by nitric oxide gas and sulphuretted-hydrogen gas when injected into a vein in a living animal: of the latter an equally unequivocal example occurs in oxalic acid, which Dr. Coindet and I found to be undiscoverable in the blood of the vena cava of a dog killed in thirty seconds by the injection of eight grains and a half of it into the femoral vein.

But the improvements that have been lately made in the methods of analysis for the detection of poisons in a state of complex mixture with organic substances have done away with a great part of the obstacles which prevented a thorough inquiry as to the existence of poisons in the blood and textures of the body. Some important researches of this kind were referred to in the last edition of the present work; and since then many additional facts, of equal variety and precision, have been communicated by different observers, but especially by Professor Orfila. Under the head of each poison an account will be given hereafter of the evidence in support of the discovery of it by chemical analysis in the blood, textures, and excretions. In the present place it is sufficient to state in general terms that the evidence is quite satisfactory in the instances of iodine, sal-ammoniac, oxalic acid, nitre, sulphuret of potassium, arsenic, mercury, copper, antimony, tin, silver, zinc, bismuth, lead, hydrocyanic acid, cyanide of potassium, carbazotic acid, sulphuretted-hydrogen, camphor, and alcohol.

Of the Organs affected by the remote action of Poisons.—Having now taken a general view of the mode in which poisons act on distant parts, I shall next consider what organs are thus brought under their operation. Poisons have been often, but erroneously, said to affect remotely the general system. A few of them, such as arsenic and mercury, do indeed appear to affect very many organs of the body. But by much the larger proportion seem on the contrary to act on one or more organs only, not on the general system.

Of the poisons which act remotely through a sympathy of distant parts with an organic injury of the textures directly acted on, many appear to act sympathetically on the heart alone. Taking the mineral acids as the purest examples of poisons that act independently of absorption into the blood-vessels, it will be seen on inquiry that all the symptoms they produce, in addition to the direct effects of the local injury, are those of depressed action of the heart,—great feebleness, fainting, imperceptible pulse, cold extremities. Even the less prominent of the secondary symptoms are almost all referrible to a depressed state of the circulation. In particular, they are not necessarily, and indeed are seldom actually, blended with any material symptom of disorder in the brain; which certainly could not be the case if the general or whole system suffered.

With respect to that more numerous class, which act remotely either through the medium of the blood or by the transmission along the nerves of an undiscernible impression made on their sentient extremities, some certainly possess a very extended influence over the great organs of the body; but the greater number are much more limited in their sphere of action. Some act chiefly by enfeebling or paralyzing the heart, others principally by obstructing the pulmonary capillaries, others by obstructing the capillaries of the general system, others by stimulating or depressing the functions of the brain or of the spinal cord, others by irritating the alimentary canal, others by stimulating one or another of the glandular organs, such as the salivary glands, the liver, the kidneys, or the lymphatic glands.

Some poisons of this kind act chiefly, if not solely, on the heart. The best examples are infusion of tobacco, and upas antiar. Sir B. Brodie observed, that when the infusion of tobacco was injected into any part of the body, it speedily caused great faintness and sinking of the pulse; and on examining the body instantly after death, he found the heart distended and paralyzed, not excitable even by galvanism, and its aortal cavities filled not with black, but with florid blood, while the voluntary muscles were as irritable as after other kinds of death.[^[37]] The upas antiar he found to be similarly circumstanced.[^[38]] Arsenic and oxalic acid are also of this kind. In an animal killed by arsenic, and in which the gullet and voluntary muscles continued long contractile, Dr. Campbell found the heart immediately after death containing arterial blood in its aortal cavities, and insensible to galvanism.[^[39]] Dr. Coindet and I frequently witnessed the same facts in animals killed with oxalic acid: When the heart at the moment of death was completely palsied and deprived of irritability, we saw the intestines moving, and the voluntary muscles contracting long and vigorously from the mere contact of the air.[^[40]]

An interesting series of investigations has been lately made by Mr. Blake, relative to the influence of poisons on the heart, when they are directly introduced into the great veins. It does not absolutely follow that an action on the heart manifested in this way proves the occurrence of a similar action when the substance is admitted into the body through more ordinary channels, such as the stomach, intestines or cellular tissue. For on the one hand, some of the substances used by this physiologist cannot be admitted into the blood through ordinary channels in the quantity necessary for developing that action on the heart, which is excited when they are injected at once into the blood-vessels. And on the other hand, the results at which he thus arrives are not always in conformity with what have been obtained by prior observers, who resorted to the ordinary channels for introducing poisons into the body. It is possible, therefore, that Mr. Blake’s researches may not have the extensive bearings, which might at first sight appear, on the physiology of poisons and remedies. Nevertheless they are in themselves full of interest. They show that the salts of magnesia, zinc, copper, lime, strontia, baryta, lead, silver, ammonia, and potash, also oxalic acid, and digitalis, if injected into the jugular vein, produce a powerful and permanent depression of the heart’s action; which is evinced by the hæmadynamometer,[^[41]] indicating diminution of pressure in the great arteries, by the heart becoming motionless or nearly so before the breathing ceases, by its muscular structure presenting little or no irritability when stimulated immediately after death, and by the left cavities being found full of florid arterial blood.[^[41]]

Other poisons act on the lungs; but probably few, perhaps none, act on them alone. Magendie found that in poisoning with tartar-emetic the lungs are commonly inflamed and sometimes even hepatized.[^[42]] Mr. Smith and M. Orfila both remarked similar signs of pulmonary inflammation in animals poisoned with corrosive sublimate.[^[43]] But these poisons produce important effects on other organs likewise.

A set of novel and important facts setting forth the frequent operation of poisons on the lungs when they are admitted directly into the blood, has been recently brought to light by the researches of Mr. Blake. Many of the poisons mentioned above as acting powerfully on the heart were found by him not to exert any influence upon the lungs, such as oxalic acid and the salts of magnesia, lime, zinc, copper, ammonia, potash, and strychnia. Others, however, such as the salts of strontia, baryta, lead, and silver, as well as digitalis, all of which powerfully affect the heart, and, in addition to these, the salts of soda, which have no action at all on the heart, and hydrocyanic acid, tobacco, and euphorbium, which influence it feebly, or even dubiously,—produce, when injected into the jugular vein, obstruction of the capillaries of the pulmonary circulation, and consequently asphyxia. This is proved by the hæmadynamometer introduced into a vein indicating great increase of pressure in the venous circulation a few seconds after the introduction of the poison; by this instrument introduced into the femoral artery indicating great diminution of arterial pressure, although the heart continues to beat vigorously; by the breathing becoming at the same time laborious, without the heart suffering; by these symptoms preceding any signs of action on the nervous system; by the heart pulsating for some time after death; and in many instances by frothy mucus having accumulated in the air-passages, and congestion and extravasation having taken place in the lungs themselves.[^[44]]

A great number of the poisons whose action is remote, operate on the brain. The most decided proof of such an action is the nature of the symptoms; which are, giddiness, delirium, insensibility, convulsions, palsy, coma. Some physiologists have also sought for evidence in the body after death, and have imagined they found it in congestion of the vessels in the brain, and even extravasation of blood there; but it will be seen under the head of Narcotic Poisons that such appearances are far from being essential, and indeed are seldom witnessed. All narcotic poisons act on the brain, and most narcotico-acrids too; but very frequently other organs are affected at the same time, and in particular the spine and heart.

The influence of poisons on the brain seems to be sometimes induced, not immediately, but indirectly through the intervention of a more direct influence on the pulmonary circulation. Thus Mr. Blake appears to have succeeded in proving that the insensibility and tetanic convulsions which immediately precede death, when certain substances, such as the salts of soda, are injected into the veins, depend simply on the obstruction directly produced in the pulmonary circulation causing increased pressure in the systemic veins, and consequently upon the brain and nervous centre generally. For when the jugular vein was opened after the development of tetanic convulsions, and blood was allowed to flow out, the nervous symptoms ceased, and the animal continued for two hours sensible and without any return of convulsions, dying eventually of hemorrhage.[^[45]] But more generally the effect produced on the brain is direct and specific. Thus opium and its active principle morphia suspend the functions of external relation, which are peculiarly dependent on the brain; while for a long time the respiration and circulation are little affected. Even when the poison is admitted directly into the veins, the pulmonary capillaries are not obstructed, and the heart is only somewhat enfeebled in its contractions;[^[46]] and in ordinary cases of poisoning with these substances the heart continues to pulsate, and the lungs also discharge their office, long after sensibility is extinguished and voluntary motion arrested,—until at length the circulation and respiration become affected consecutively by the depressed state of the nervous system.

Some poisons act specifically on the spinal cord. Those which are best known to possess such an action are nux-vomica, the other species of plants which, like it, contain strychnia, and also conia and the wourali poison. The tribe of poisons of which nux-vomica may be taken as the type excite violent fits of tetanus, during the intervals of which the mind and external senses are quite entire; and death takes place during a paroxysm, apparently from suffocation caused by spasmodic fixing of the chest. Their action on the spine is quite independent of any action on the brain; if indeed such action exist at all. For when the spinal cord is separated from the brain by dividing the medulla oblongata, the effects on the muscles supplied by the spinal cord are produced as usual.[^[47]] Conia, the active principle of hemlock, according to my own researches, produces in the lower animals, howsoever introduced, gradually increasing paralysis, without insensibility or delirium, and without the circulation or respiration being for some time affected, till at length death takes place from stoppage of the breathing by palsy of the respiratory muscles; and after death the heart continues beating vigorously, the muscles contract when irritated, and arterialization of the blood in the lungs may be kept up long by maintaining artificial respiration. In this instance it would appear, that the first effect is arrestment of the functions of the spinal cord; that the paralysis does not depend upon a direct action on the muscles; and that neither the brain, heart, nor lungs can be influenced, except secondarily through the consequences of general muscular paralysis.[^[48]] Many poisons which act on the brain also act on the spinal cord.

Other poisons apparently possess the singular property of impeding or arresting the general capillary circulation, and produce their tangible effects more or less through the medium of this operation. Such at least are the inferences which seem to flow from the researches of Mr. Blake; who found that many substances, soon after they are injected backwards by the axillary artery into the aorta, produce increased pressure in the arterial system indicated by the hæmadynamometer during life, and frequently congestion of the membranous textures as observed after death. Some substances have no effect of this kind. Others act on the general capillaries in concurrence with a similar action on the capillaries of the pulmonary circulation, such as the salts of strontia, baryta, lead, silver, and soda, euphorbium, tobacco and digitalis. But a few, such as potash and ammonia, with their salts, seem to influence the capillaries of the general circulation only.[^[49]] These are important conclusions, if legitimate; but it cannot be denied, that the facts on which they are based must be very difficult to isolate and observe with accuracy and without bias.

The organs not immediately necessary to life may be likewise all acted on by poisons indirectly. On this subject details are not called for at present. It may be sufficient to remark that there is hardly a considerable organ in the body, except perhaps the spleen and pancreas, which is not acted on by one poison or another. Arsenic inflames the alimentary mucous membrane, mercury the salivary organs and mouth, cantharides the urinary organs, chromate of potass the conjunctiva of the eyes, manganese the liver; iodine acts on the lymphatic glands; lead on the muscles; and spurred rye causes gangrene of the limbs.

Some poisons, as was already mentioned, may act on one important organ only, every other being left undisturbed: thus nux-vomica in general acts only on the spine. But much more commonly they act on several organs at once; and the action of some of them is complicated in an extreme degree. I may instance oxalic acid and arsenic. Oxalic acid when swallowed irritates and inflames the stomach directly, and acts indirectly on the brain, the spine, and the heart. A large dose causes sudden death by paralyzing the heart; if the dose is somewhat less, the leading symptom is violent tetanic spasm, indicating an action on the spine, and death takes place during a paroxysm, the heart continuing to contract for some time after; if the dose is still less, the spasms, at first distinct, become by degrees fainter and fainter, while the sensibility in the intervals, at first unimpaired, becomes gradually clouded, till at length pure coma is formed without convulsions,—thus indicating an action on the brain. As for arsenic, coupling together the symptoms during life and the appearances in the dead body, it will be seen afterwards to have the power of acting on the brain, heart, and lungs,—the throat, gullet, stomach, and intestines,—the lining membrane of the nostrils and eyelids,—the kidneys, bladder, and vagina; and, what is remarkable, proofs of an action on all these parts may be witnessed in the course of a single case. The effects of mercury are hardly less multifarious.

Section II.—On the Causes which modify the Actions of Poisons.

By a variety of causes the action of poisons may be modified both in degree and in kind. The most important of them are—quantity; state of aggregation; state of chemical combination; mixture; difference in tissue; difference in organ; habit; idiosyncrasy; and lastly, certain states of disease.

1. Quantity affects their action materially. Not only do they produce their effects more rapidly in large doses; it is sometimes even quite altered in kind. A striking example has just been related in the case of oxalic acid; which, according to the dose, may corrode the stomach, or act on the heart, or on the spine, or on the brain. In like manner arsenic in a small dose may cause gastritis of several days’ duration; while a large dose may prove fatal in two or three hours by affecting the action of the heart. White hellebore in small doses excites inflammation in the stomach and bowels, in larger doses giddiness, convulsions, coma; and in either way it may prove fatal.

2. As to state of aggregation,—poisons act the more energetically the more minutely they are divided, and hence most energetically when in solution. Some which are very energetic in the fluid state, hardly act at all when undissolved. Morphia, the alkaloid of opium, may be given in powder to a dog without injury in a dose, which, if dissolved in oil or alcohol, would soon kill several. Previously dissolving poisons favours their action in two ways,—by diffusing them quickly over a large surface, and by fitting them for entering the bibulous vessels. Poisons, before being absorbed, must be dissolved; and hence, those which act though solid and insoluble in water, must, as a preliminary step, be dissolved by the animal fluids at the mouths of the vessels. In this way the poisonous effects of carbonate of baryta and arsenite of copper are explained; for though insoluble in water, they are soluble in the juices of the stomach.

Differences in aggregation, like differences in quantity, may affect the kind as well as the degree of action. Camphor in fragments commonly causes inflammation of the stomach; dissolved in spirit or olive oil, it causes delirium or tetanus and coma.

The reduction of certain poisons to the state of vapour serves the same end as dissolving them. When poisons are to be introduced by the skin, no previous operation is more effectual than that of converting them into vapour.

3. The next modifying cause is chemical combination. This is sometimes nothing more than a variety of the last. If a poison, in combining with another substance, acquire greater solubility, it also generally acquires greater activity, and vice versa: Morphia, itself almost inert, because insoluble, becomes active by uniting with acids, for they render it very soluble: Baryta as a very active poison, becomes quite inert by uniting with sulphuric acid, for the sulphate of baryta is altogether insoluble.

In regard to the influence of chemical combination two general laws may be laid down. One is, that poisons which only act locally, have their action much impaired or even neutralized, in their chemical combinations. Sulphuric acid and muriatic acid on the one hand, and the two fixed alkalis on the other, possess a violent local action; but if they are united so as to form sulphates or muriates, although still very soluble, they become merely gentle laxatives. But the case is altered if either of the combining poisons also act by entering the blood. For the second general law is, that the action of poisons which operate by entering the blood, although it may be somewhat lessened, cannot be destroyed or altered in their chemical combinations. Morphia acts like opium if dissolved in alcohol or fixed oil; if an acid be substituted as the solvent, a salt is formed which is endowed with the same properties: The sulphate, muriate, nitrate, acetate of morphia all act like opium. Strychnia, arsenic, hydrocyanic acid, oxalic acid, and many more come under the same denomination: Each produces its peculiar effects, with whatever substance it is combined, provided it do not become insoluble.

Mr. Blake has recently laid down what may be considered a branch or corollary of the second of these general propositions, and has confirmed it by many appropriate experimental facts,—namely, that the salts of the same base produce the same actions, independently of the acids with which they are combined.[^[50]] The law, however, is a more general one, as given above, and was stated in former editions of the present work. It applies not only to bases, but likewise to acids, such as the hydrocyanic, oxalic, arsenious, and arsenic acids, and also to neutral organic principles which act through the blood, such as picrotoxin, colocynthin, elaterin, and narcotin.

The same author considers it to be also a probable conclusion from a variety of experiments on the salts of various bases, that those salts which are isomorphous, or possess the same crystalline form, are closely allied in action.[^[51]]

4. The effect of mixture depends partly on the poisons being diluted. Dilution, by prolonging the time necessary for their being absorbed, commonly lessens their activity; yet not always; for if a poison which acts through the blood is also a powerful irritant, moderate dilution will enable it to enter the vessels more easily: a small dose of concentrated oxalic acid acts feebly as an irritant or corrosive; moderately diluted, it quickly enters the blood and causes speedy death.[^[52]] The effect of mixture may depend also in part on the mere mechanical impediment interposed between the poison and the animal membranes. This is particularly obvious when the mass containing the poison is solid or pulpy; for then the first portions of the poison that touch the membrane may cause an effort of the organ to discharge the rest beyond the sphere of action,—if, for example, it is the stomach,—by vomiting. The effect of mixture in interposing a mechanical impediment is also well illustrated where the substance mixed with the poison is a fine, insoluble powder, capable of enveloping its several particles. Thus it is that small, yet poisonous doses of arsenic may be swallowed and retained with impunity, if mixed with finely powdered charcoal, magnesia, and probably cinchona-bark, or the like. Besides diluting and mechanically obstructing their application, the admixture of other substances may alter the chemical nature of poisons, and so change their action.

It is important to keep in view, that the influence of mixture may be exerted in consequence of the cavity into which a poison is introduced being at the time filled with contents. Some of the most powerful and unerring poisons may in such circumstances altogether fail to produce their usual effect, if speedily vomited. Thus Wibmer notices the case of a man, who swallowed an ounce and a half of arsenic after a very hearty meal, had merely a severe attack of vomiting with subsequent colic, and got quite well in four days.[^[53]] And a still more pointed instance has been briefly mentioned by Dr. Booth of Birmingham, where an ounce of corrosive sublimate was swallowed after a full meal without any material ill consequence, vomiting having been speedily induced.[^[54]]

5. Difference of tissue is an interesting modifying power in a physiological point of view, but does not bear so directly on medico-legal practice as the rest, and may therefore be passed over cursorily.

On the corrosives and irritants a difference of tissue acts but indirectly: their effects vary not so much with the tissue as with the organ of which it forms part. But as to poisons which act through the blood, their energy must evidently depend on the activity of absorption in each texture.

The cutaneous absorption is slow, on account of the obstacle presented by the cuticle, and by the intricate capillaries of the true skin. Accordingly many active poisons are quite inert when applied to the unbroken skin, or even to the skin deprived of the cuticle. Hydrocyanic acid, perhaps the most subtle of all poisons, was found by Coullon to have no effect when dropped on the skin of a dog.[^[55]] Some authors have even gone so far as to deny that poisons can be absorbed at all through the skin, unless they are pressed by friction through the cuticle. But this is an error; most gaseous poisons, such as carbonic acid and sulphuretted hydrogen, and some solid poisons when volatilized, such as the vapours of cinnabar, will act though simply placed in contact with the skin; and there is distinct evidence that corrosive sublimate will bring on mercurial action in the form of a warm bath, or when used as a liniment.

On the mucous membrane of the stomach and intestines, poisons act much more energetically than on the skin; which clearly depends in a great measure on the superior rapidity of absorption there,—or, according to some, on the facility with which poisons come in contact with the sentient extremities of nerves.

The serous membranes possess an activity of absorption which hardly any other unbroken texture can equal. Accordingly many poisons act much more rapidly through the peritonæum than through the stomach. When oxalic acid is introduced under the same collateral circumstances into the stomach of one dog and the peritonæum of another, the dose may be so apportioned, that the same quantity, which does not prove fatal to the former, kills the latter in fourteen minutes.[^[56]]

While the preceding modes in which poisons enter the blood are indirect, they may be introduced directly by a wound in the vein. There is no way in which poisons, that act through the blood, prove more rapidly fatal. Some which act very slowly through the stomach cause instant death when injected into a vein. A peculiar variety of this mode of introducing poisons deserves to be distinguished, namely, the application of them to a wound. If the surface bleeds freely, they may not act at all, because they are washed away. But if they adhere, they soon enter the divided veins. Hence, if they act in small doses, this mode of applying them is hardly less direct than if they were at once injected into a vein.

So far the effect of difference in tissue has been determined. Poisons that act through the blood act least energetically on the skin, more actively on the alimentary mucous membrane, still more so on serous membranes, and most powerfully of all when introduced directly into a vessel. There are other textures, however, which merit notice, although their place in the scale of activity has not been exactly settled.

On the mucous membrane of the pulmonary air-cells and tubes, poisons act with a rapidity which is scarcely surpassed by their direct introduction into a vein. This is plainly owing to the exceeding delicacy and wide surface of the membrane. Hence three or four inspirations of carbonic oxide gas will cause instant coma. A single inspiration of the noxious gas of privies has caused instant extinction of sense and motion. Nay, liquid poisons have been known to act through the same channel with almost equal swiftness. For M. Ségalas found that a solution of extract of nux-vomica caused death in a few seconds when injected in sufficient quantity into the windpipe; and that half a grain will thus kill a dog in two minutes, while two grains will rarely prove fatal when injected into the stomach, peritonæum, or chest.[^[57]]

As to the nervous tissue, it is a fact worthy of mention, that the poisons which appear to act on the sentient extremities of the nerves, do not act at all on the cut surface of the brain and nerves, or upon any part of the course of the latter. This has been proved with respect to most active narcotics.

The power of the cellular tissue as a medium of absorption, has not been, and cannot easily be, ascertained. On the one hand it is difficult to apply poisons to it, without also applying them to the mouths of divided vessels; and, on the other hand, it is difficult to make a set of experiments for comparison with others on the stomach, pleura, or peritonæum, as the cellular tissue does not form an expanded cavity, and consequently, the extent of surface to which a poison is applied cannot be made the same in each experiment of a series. It is a ready medium, however, for admitting poisons into the blood, especially if an artificial cavity be made where the tissue is loose, as, for example, by separating the skin from the muscles of the back with the finger introduced through a small incision in the integuments.

The variations caused by difference of tissue in the activity of poisons have been viewed in the previous remarks as depending chiefly on the relative quickness with which absorption goes on. But in this way it is impossible to explain the whole amount of the differences sometimes observed. Some poisons cause death when applied to a wound in the minutest quantity, but are quite harmless when swallowed in large doses: Others are diminished a little in activity, but still remain powerful and fatal poisons. There is not much difference in the power of arsenic when it is applied to different textures, the skin excepted. But oxalic acid injected into the peritonæum will act eight or ten times more rapidly than when swallowed and the poison of the viper may prove fatal to a man through a wound in almost invisible doses, while the whole poison of six vipers may be swallowed by so small a creature as a blackbird, with complete impunity.[^[58]] Differences in the absorbing power of the tissues cannot explain these facts.

The only rational way of accounting for them is by supposing that a part of the poison is decomposed,—the change being greatest where absorption is slowest and the power of assimilation strongest, namely, in the stomach,—and least where absorption is quickest and assimilation almost wanting, namely, in a wound. This explanation derives support from the different effects of change of tissue on poisons of the different kingdoms. Mineral poisons are least, and animal poisons are most, affected in their action by differences of tissue, while vegetable poisons hold the middle place:—an arrangement which coincides with the respective difficulty of decomposition among mineral, vegetable, and animal substances generally, whether under physical or under vital processes.[^[59]]

6. With respect to differences arising from difference of organ, these will, of course, be partly attributable to differences in tissue, but not altogether. For example, in the case of the pure corrosives or irritants, the injury caused will depend for its danger on the importance of the organ to the general economy of the body: Inflammation caused by a local poison in the stomach will be more quickly fatal than that excited in the intestines only; and such a poison may act violently on the external parts without materially impairing the general health.

7. Habit and Idiosyncrasy.—The remarks to be made under the present head are important in a medico-legal point of view: for they show how one man may be poisoned by a substance generally harmless, and another not harmed by a substance usually poisonous.

The tendency of idiosyncrasy is generally to increase the activity of poisons, or even to render some substances deleterious which are commonly harmless.

The effect of opium in medicinal doses is commonly pleasant and salutary; but in some individuals it produces disagreeable and even dangerous effects. Calomel, which in moderate doses is for the most part a mild laxative or sialagogue, will cause in some people, even in the dose of a few grains, violent salivation, ulceration of the mouth, nay, fatal gangrene. On the other hand, a few substances, which to most people are actively poisonous, have on some individuals comparatively little effect. There are extremely few poisons, however, in regard to which this kind of idiosyncrasy is well established and prominent. Mercury and alcohol are examples. The compounds of mercury, which in moderate quantity are mildly laxative or sialagogue to most people, but to some persons dangerously poisonous in very small doses, would, on the contrary, appear in other constitutions to be extremely inactive; for it has occasionally been found impossible to bring on the peculiar constitutional action of mercury by continuing the use of its preparations for months together. In general children are not easily affected by calomel as a sialagogue, but easily by its laxative action. As to alcohol, it is a familiar fact, that independently of the effects of habit, there are some constitutions which cannot be brought under the influence of intoxicating liquors without an extraordinary quantity of them and a long-continued debauch, while others are overpowered in a short space of time, and by very moderate excess; and there is no reason to doubt that very great constitutional differences also prevail in regard to the operation of a single large dose. A rarer idiosyncrasy is unusual insensibility to the action of opium. I am acquainted with a gentleman unaccustomed to the use of opium who has taken without injury nearly an ounce of good laudanum,—a dose which would certainly prove fatal to most people.

But not only does idiosyncrasy modify the action of poisons: Through its means, too, some substances are actually poisonous to certain individuals, which to mankind in general are unhurtful, nay, even nutritive.

With some people all kinds of red fish, trout, salmon, and even the richer white fish, herring, mackerel, turbot, or holibut, disagree as it is called—that is, act after the manner of poisons: They produce fainting, sickness, pain of the stomach; and if they were not speedily evacuated by vomiting, dangerous consequences might ensue. The same is often the case with mushrooms. The esculent mushrooms act on some people nearly in the same way as the poisonous varieties. Bitter almonds and other vegetable substances that contain hydrocyanic acid, sometimes produce stupor or nettle-rash in the small quantities used for seasoning food. In like manner many flowers, which to most persons are agreeable and not injurious, cannot be kept in the same room with some people on account of the severe nervous affections that are developed.

This idiosyncrasy may even be acquired. One of my relations, who was for many years violently affected by very small quantities of the richer kinds of fish, used at a previous period to eat them, and can now again do so, with impunity. Many people have acquired a similar idiosyncrasy with respect to eggs; instances of the same kind will be afterwards mentioned in respect to shell-fish, particularly muscles; indeed there are probably few articles of food in regard to which such idiosyncrasies may not in a few rare instances be met with, if we except the grains and common kinds of butcher-meat. I may add, that from facts which have come under my notice, I have sometimes suspected that a similar idiosyncrasy may be acquired in a slight degree, and for a short time only, in regard even to some kinds of butcher-meat, especially the flesh of young animals and pork. On this subject some illustrations will be found at the close of the chapter on diseased and decayed animal matter.

It does not appear well ascertained, that the effect of idiosyncrasy is ever to impair materially the energy of poisons, except in the instances of mercury, alcohol, and opium.

On the contrary, the tendency of habit when it does affect their energy, is, with a few exceptions, to lessen it. By the force of habit a person may take without immediate harm such enormous quantities of some poisons as would infallibly kill an unpractised person or himself when he began. There have been opium-eaters in this country who took for days together ten or even seventeen ounces of laudanum daily.

The influence of habit has been ascertained precisely in the case of a few common poisons only. On the whole, it would appear that more change is effected by habit in the action of the organic than in that of the inorganic poisons; and that of the former, those which act on the brain and nervous system, and produce narcotism, are altered in the most eminent degree. The best examples of the influence of habit are opium and vinous spirits. The action of such poisons is not always, however, entirely thrown away; they still produce some immediate effect; and farther, by being frequently taken, they may slowly bring on certain disease, or engender a predisposition to disease. A very singular exception to this rule prevails in the instance of tobacco; which, under the influence of habit, may be smoked daily to a considerable amount, and, so far as yet appears, without any cumulative effect on the constitution, like that of opium-eating or drinking spirits.

The inorganic poisons are most of them little impaired in activity by the force of habit. The pure irritants, indeed, do lose a little of their energy: for it seems that persons have acquired the power of swallowing with impunity considerable doses of the mineral acids. But as to inorganic poisons that enter the blood, habit certainly does not diminish, probably rather increases, their power. There is no satisfactory evidence, that a person by taking gradually-increasing doses of arsenic may acquire the power of enduring a considerably larger dose than when he began: On the contrary, the stomach rather becomes more tender to the subsequent dose by each repetition. I have little hesitation in avowing my disbelief of the alleged cases of arsenic-eaters and corrosive-sublimate-eaters, who could swallow whole drachms at once with impunity. Some have expressed surprise at this statement having been made in former editions of the present work, when there is such authority as Byron, Pouqueville, &c., for the hackneyed story of Soleyman, the sublimate-eater of Constantinople, who lived to the age of a hundred, eating a drachm of corrosive sublimate daily. I must avow, however, that such reporters of a feat so very extraordinary, and where deception was so highly probable, are to me no authority at all.

In the relative influence of habit on poisons of the three kingdoms of nature, a new argument will be discovered for the opinion given above respecting the partial decomposition of organic poisons in some of the tissues. In fact this partial decomposition accounts very well for the effect of habit: The effect of habit is probably nothing more than an increased power acquired by the stomach of decomposing the poison,—just as it gradually acquires an increased facility in digesting some alimentary substances which are at first very indigestible.

8. The last modifying cause to be mentioned comprehends certain diseased states of the body. The effect of disease, like that of habit, is in general to impair the activity of poisons. But it is only in the instance of a few diseases that this diminution is so strongly marked as to be important in relation to medical jurisprudence.—In the continued fever of this country there is a diminished susceptibility of the constitutional action of mercury; and this peculiarity is very strongly marked in the yellow fever, as well as in the bilious fevers generally of tropical climates. In some varieties of typhoid fever there is obviously a diminished sensibility to the action of wine and other spirituous liquors; but this diminution in a great majority of cases is much inferior to what some physicians have represented.—In severe dysentery the susceptibility of the narcotic action of opium is so much impaired, that a person unaccustomed to the use of that drug, may continue to take daily, for several days together, a quantity which might prove fatal to him in a state of health. In the severe form which dysentery occasionally puts on in this country I have known a patient take from twenty-four to thirty grains of opium daily, and retain it all, without experiencing more than a mild narcotic action.—In epidemic cholera the same insensibility has been remarked to the operation of opium.—It also occurs in the instance of excessive hemorrhagy.—According to the doctrines and practice of the present dominant school in Italy, there is an unusual insensibility during inflammatory dropsy to the irritant action of gamboge, so that sixty or eighty grains may be taken without harm.—There is no disease, however, in which the power of mitigating the action of poisons is more remarkably exhibited, than in tetanus: It is often scarcely possible to bring on the narcotic action of opium by any doses which can be administered; calomel, too, acts with much less energy than usual; and even common purgatives must be administered in doses considerably larger than those required in most other disorders.—Mania is similarly circumstanced: almost all remedies must be given in increased doses, narcotic remedies in particular. But there is good reason for believing that the impaired susceptibility of the action of poisons remarked in this disorder is far from being always so great as some have alleged.—Another disease allied to the last, where the diminution of susceptibility is often great, is delirium tremens. It has in particular been often found, that to produce sleep in this disease opium must be given in frequent large doses,—so large indeed, that they would undoubtedly prove fatal to a person in health. At the same time it is worthy of remark, that in some cases of delirium tremens, even violent in degree, the peculiarity now specified, as I have myself several times witnessed, is far from being strongly marked.—Hydrophobia always, and hysteria sometimes, impair the activity of poisons. I have seen cases of hysteria, more particularly those assuming the form of tetanus, where very large doses of opium were required to produce a calmative effect and sleep; and in hydrophobia it is well shown that the narcotic action of opium is not produced even by large doses often repeated.—The same state occurs in excessive hemorrhage.

In the operation of this class of modifying agents it is a general law, to which there are probably few exceptions, that they chiefly affect poisons of the organic kingdoms, and the narcotics above all. At least in the instance of most mineral poisons their influence is very inferior. Their operation may be accounted for in various ways. Sometimes, as in dysentery and cholera, the poison is carried with unusual rapidity through the alimentary canal. Sometimes again it remains comparatively inert, because on account of the impaired activity of absorption, it is not taken up with the usual quickness by the absorbent vessels. And sometimes, as in the instance of tetanus, mania, and rabies, the nervous system is in a state of peculiar excitement, by which the customary action of the poison is in a great measure, if not entirely, counteracted.

In a few diseased states of the system there is an increased susceptibility of the action of poisons: and it is important that the medical jurist should attend to this circumstance. When a poison has a tendency to bring on a peculiar pathological state of the system, or of a particular organ, which state is also produced by a disease existing at the time or impending, violent and even fatal consequences may ensue from doses of poisons which in ordinary circumstances are innocuous or beneficial. Thus in persons affected with apoplexy an ordinary dose of opium may accelerate death; and in people even with a mere tendency to apoplexy, if it is strongly marked, or appears from what are called warning symptoms to be on the point of developing itself, a common dose of such narcotics as occasion determination to the brain may excite the apoplectic attack. Thus, too, in cases of inflammatory disorders of the alimentary canal, irritating substances, in doses not otherwise injurious, may produce dangerous impressions on the tender membrane with which they come in contact. But in respect to this last example, it must be remarked, that the improvements or the caprice of medical practice have gone directly in face of the rule, by suggesting that some internal inflammations of the alimentary canal may be successfully treated with irritating remedies.

I might here perhaps have added among the causes which modify the action of poisons, sleep, and the administration of other poisons. The latter subject, however, will be better considered at the end of the Individual Poisons, under the title of Compound Poisoning. The former agent is of doubtful effect. Some observations on its influence will be found in the chapter on the Evidence of General Poisoning, p. [41].

Application of the preceding remarks to the Treatment of Poisoning. As an appendix to what has been said respecting the physiological action of poisons, and the causes by which it is liable to be modified, I shall here state shortly certain applications to the treatment of poisoning.

In the instance of internal poisoning, the great object of the physician is to administer an antidote or counter-poison. Antidotes are of two kinds. One kind takes away the deleterious qualities of the poison before it comes within its sphere of action, by altering its chemical nature. The other controls the poisonous action after it has begun, by exciting a contrary action in the system. In the early ages of medicine almost all antidotes were believed to be of the latter description, but in fact very few antidotes of the kind are known.

Chemical antidotes operate in several ways, according to the mode of action of the poison for which they are given. If the poison is a pure corrosive, such as a mineral acid, it will be sufficient that the antidote destroy its corrosive quality: Thus the addition of an alkali or earth will neutralize sulphuric acid, and destroy or at least prodigiously lessen its poisonous properties. In applying this rule care must be taken to choose an antidote which is either inert in itself, or, if poisonous, is, like the poison for which it is given, a pure corrosive or local irritant, and one whose properties are reciprocally neutralized.

If the poison, on the other hand, besides possessing a local action, likewise acts remotely through absorption, or by an impression on the inner coat of the vessels, mere neutralization of its chemical properties is not sufficient; for we have seen above that such poisons act throughout all their chemical combinations which are soluble. Here, therefore, it is necessary that the chemical antidote render the poison insoluble or nearly so; and insoluble not only in water, but likewise in the animal fluids, more particularly the juices of the stomach. The same quality is desirable even in the antidotes for the pure corrosives; for it often happens that in their soluble combinations these substances retain some irritating, though not any corrosive power. When we try by the foregoing criterions many of the antidotes which have been proposed for various poisons, they will be found defective; and precise experiments have in recent times actually proved them to be so.

The other kind of antidote operates not by altering the form of the poison, but by exciting in the system an action contrary to that established by the poison. On considering attentively, however, the phenomena of the action of individual poisons, it will be found exceedingly difficult to say what is the essence of a contrary action, and still more how that counter-action is to be brought about. Accordingly, few antidotes of the kind are known. Physiology or experience has not yet brought to light any mode of inducing an action counter to that caused by arsenic and most of the irritant class of poisons. It appears probable that the remote operation of lead may be sometimes corrected by mercury given to salivation, and that the violent salivation caused by mercury may be occasionally corrected by nauseating doses of antimony. But these are the only instances which occur to me at present of antidotes for irritant poisoning which operate by counter-action, unless we choose to designate by the name of antidote the conjunction of remedial means which constitute the antiphlogistic method of cure. In the class of narcotics we are acquainted with equally few constitutional antidotes, although the nature of the action of these poisons seems better to admit of them. Ammonia is to a certain extent an antidote for hydrocyanic acid, but by no means so powerful as some persons believe; and I am not sure that in this class of poisons we can with any propriety mention another antidote of the constitutional kind.

On the whole, then, it is chiefly among the changes induced by chemical affinities that the practitioner must look for counter-poisons; and the ingenuity of the toxicologists has thence supplied the materia medica with many of singular efficacy. When given in time, magnesia or chalk is an antidote for the mineral acids and oxalic acid, albumen for corrosive sublimate and verdigris, bark for tartar-emetic, common salt for lunar caustic, sulphate of soda or magnesia for sugar of lead and muriate of baryta, chloride of lime or soda for liver of sulphur, vinegar or oil for the fixed alkalis; and these substances act either by neutralizing the corrosive power of the poison, or by forming with it an insoluble compound.

In recent times a new object in the treatment of poisoning has been pointed out by the discoveries made in its physiology. As it has been proved that many of the most deadly poisons enter the blood, and in all probability act by circulating with that fluid, so it has been inferred that an important object in the treatment is to promote their discharge by the natural secretions. In support of this reasonable inference it has been lately rendered probable by Orfila, as will be seen under the head of the treatment of the effects of arsenic, that it is of great advantage in some forms of poisoning to increase the discharge of urine.

In the instance of external poisoning the main object of the treatment is to prevent the poison from entering the blood, or to remove it from the local vessels which it has entered.

One mode, which has been known to the profession from early times, and after being long in disuse was lately revived by Sir D. Barry, and applied with success to man, is the application of cupping-glasses to the part where the poison has been introduced.[^[60]] This method may act in various ways. It certainly prevents the farther absorption of the poison by suspending for a time the absorbing power of the vessels of the part covered by the cup. It also sucks the blood out of the wound, and may consequently wash the poison away with it. Possibly it likewise compresses the nerves around, and prevents the impression made by the poison on their sentient extremities from being transmitted along their filaments.

Another mode is by the application of a ligature between the injured part and the trunk, so as to check the circulation. This is a very ancient practice in the case of poisoned wounds, and is known even to savages. But as usually practised it is only a temporary cure: As soon as the ligature is removed the effects of the poison begin. It may be employed, however, for many kinds of poisoning through wounds, so as to effect a radical cure. We have seen that most poisons of the organic kingdom are in no long time either thrown off by the system or decomposed in the blood. Hence if the quantity given has not been too large, recovery will take place. Now, by means of a ligature, which is removed for a short time at moderately distant intervals, a poison, which has been introduced into a wound beyond the reach of extraction, may be gradually admitted into the system in successive quantities, each too small to cause death or serious mischief, and be thus in the end entirely removed and destroyed. Such is a practical application which may be made of some ingenious experiments performed not long ago by M. Bouillaud with strychnia, the poisonous principle of nux-vomica.[^[61]]

The last mode to be mentioned is by a combination of the ligature with venesection, deduced by M. Vernière from his experimental researches formerly noticed (p. [19]). Suppose a fatal dose of extract of nux-vomica has been thrust into the paw of a dog; M. Vernière applies a tight ligature round the limb, next injects slowly as much warm water into the jugular vein as the animal can safely bear, and then slackens the ligature. The state of venous plethora thus induced completely suspends absorption. The ligature is next tied so as to compress the veins without compressing the arteries of the limb, and a vein is opened between the wound and the ligature in such a situation, that the blood which flows out must previously pass through, or at least near the poisoned wound. When a moderate quantity has been withdrawn, the ligature may be removed with safety; and the extraction of the poison may be farther proved by the blood that has been drawn being injected into the veins of another animal; for rapid death by tetanus will be the result.[^[62]] It is not improbable that in this plan the preliminary production of venous plethora may be dispensed with; and then the treatment may be easily and safely applied to the human subject.

CHAPTER II.
ON THE EVIDENCE OF GENERAL POISONING.

This subject is purely medico-legal. It comprehends an account of the various kinds of evidence by which the medical jurist is enabled to pronounce whether poisoning in a general sense (that is, without reference to a particular poison), is impossible, improbable, possible, probable, or certain. It likewise comprises an appreciation of the circumstances which usually lead the unprofessional, as well as the professional, to infer correctly or erroneously a suspicion of such poisoning.

Under the present head might likewise be included the history of poisoning, the art of secret poisoning, and some other topics of the like kind. But the want of proper documents, and the unmeasured credulity which has prevailed on the subject of poisoning throughout all ages down to very recent times, has entangled these subjects in so intricate a maze of fable, that a notice of them, sufficiently detailed to interest the reader, would be quite misplaced in this work.

On the art of secret poisoning, however, as having been once an important object of medical jurisprudence, it might be expected that some comments should here be offered. But really I do not see any good reason for wading through the mass of credulous conjectures and questionable facts, which have been collected on the subject, and which have been copied into one modern work after another, for no other cause than that they are of classic origin, or feed our appetite for the mysterious. No one now seriously believes that Henry the Sixth was killed by a pair of poisoned gloves, or Pope Clement the Seventh by a poisoned torch carried before him in a procession, or Hercules by a poisoned robe, or that the operation of poisons can be so predetermined as to commence or prove fatal on a fixed day, and after the lapse of a definite and remote interval. With regard to the noted instances of secret poisoning, which occurred towards the close of the seventeenth century in Italy and France, it is plain to every modern toxicologist, from the only certain knowledge handed down to us of these events, that the actors in them owed their success rather to the ignorance of the age, than to their own dexterity. And as to the refined secrets believed to have been possessed by them, it is sufficient here to say, that although we are now acquainted with ten times as many and ten times as subtle poisons as were known in those days, yet none exist which are endowed with the hidden qualities once so universally dreaded.

The crime of poisoning, from its nature, must always be a secret one. But little apprehension need be entertained of the art of secret poisoning as understood by Toffana or Brinvilliers,[^[63]] or as it might be improved by a modern imitator. It seems to have escaped the attention of those who have written on the subject, that the practice of such an art requires the knowledge not only of a dexterous toxicologist, but also of a skilful physician; for success must depend on the exact imitation of some natural disease. It is only among medical men, therefore, and among the higher orders of them, that a Saint-Croix can arise now-a days. How little is to be dreaded on that head is apparent from the domestic history of the European kingdoms for the last half century, compared with their history some centuries ago. Few medical men have even been suspected, and those few only upon visionary grounds, and under the impulse of violent political feeling.[^[64]] In one late instance only, so far as I am aware, has it been proved that the physician’s art was actually prostituted to so fearful a purpose; and the detection of the crime in that case shows how difficult concealment will always be wherever justice is administered rigorously, and medico-legal investigations skilfully conducted.[^[65]]

Two extraordinary incidents which happened lately in Germany may appear at first sight at variance with these views. I allude to the cases of Anna Margaretha Zwanziger and Margaretha Gottfried, which justly excited much interest where they occurred, and are notorious to continental toxicologists. Zwanziger, while serving as housekeeper in various families in the territory of Bayreuth in Bavaria during the years 1808 and 1809, contrived to administer poison,—sometimes under the instigation of mere revenge or spite, sometimes for the purpose of clearing the way for her schemes of marriage with her masters,—to no fewer than seventeen individuals in the course of nine months; and of these three died.[^[66]] Gottfried, a woman in affluent circumstances and tolerable station in the town of Bremen, was even more successful. For she pursued her criminal career undiscovered for fifteen years; and when detected in 1828 had murdered actually fourteen persons, and administered poison unsuccessfully to several others. Her motive, as in the case of Zwanziger, was the mere gratification of a malevolent temper, or the removal of supposed obstacles to her matrimonial dreams. In neither of these instances, however, did the criminal possess any particular skill, or observe much measure in her proceedings. The cases of poisoning were of the common kind,—produced by arsenic,—proving in general quickly fatal,—and presenting the ordinary phenomena. I cannot help thinking, therefore, that the events now alluded to prove rather the ineffectiveness of the police where they happened, than the adroitness of the actors by whom they were brought about; and that they constitute no sound objection to the statement, that the art of secret poisoning is now unknown, and is not likely to be again revived.

It must be granted, indeed, that the late discoveries in chemistry and toxicology have made poisons known which might be employed in such a way as to render suspicion unlikely, and to baffle inquiry. But the methods now alluded to are hitherto very little known; they cannot easily be attempted on account of the rarity and difficult preparation of the poisons; they can never be practised except by a person conversant with the minute phenomena of natural disease; and it is no part of the object of this work to make them public.

The evidence, by which the medical jurist is enabled to pronounce on the existence or non-existence of poisoning in general, and to determine the subordinate questions that relate to it, is derived from five sources,—1, the symptoms during life; 2, the appearances in the dead body; 3, the chemical analysis; 4, experiments and observations on animals; and 5, certain moral circumstances, which are either inseparably interwoven with the medical proof, or cannot be accurately appreciated without medical knowledge.

Section I.—Of the Evidence from Symptoms.

Not many years ago it was the custom to decide questions of poisoning from the symptoms only. Till the close of last century, indeed, no other evidence was accounted so infallible: and for the simple reason, that in reality the other branches of evidence were even more imperfectly understood. So lately as 1763, and even in Germany, the solemn opinions of whole colleges were sometimes grounded almost exclusively on the symptoms.[^[67]] About that time, however, doubts began to be entertained of the infallibility of such evidence; these doubts have since assumed gradually a more substantial form; and it is now laid down by every esteemed author in Medical Jurisprudence, that the symptoms, however exquisitely developed, can never justify an opinion in favour of more than high probability.[^[68]] In laying down this doctrine medical jurists appear to me to have injudiciously confounded together actual symptoms with their general characteristics. If the doctrine is to be held as applying to the evidence from symptoms, only so far as they are viewed in questions of general poisoning,—that is, as applying to the general characters merely of the symptoms,—it is deduced from accurate principles. But if it is likewise to be applied, as recent authors have done, to the actual symptoms produced by particular poisons, and in all cases whatever of their action, then it is a rule clearly liable to several important exceptions. These exceptions will be noticed under the heads of the mineral acids, oxalic acid, arsenic, corrosive sublimate, nux vomica, &c. At present it is only the general characters of the symptoms, and the points in which they differ from the general characters of the symptoms of natural disease, that I propose to consider.

The chief characteristics usually ascribed to the symptoms of poisoning considered generally, are, that they commence suddenly and prove rapidly fatal,—that they increase steadily,—that they are uniform in nature throughout their course,—that they begin soon after a meal,—and that they appear while the body is in a state of perfect health.

1. The first characteristic is the suddenness of their appearance and the rapidity of their progress towards a fatal termination. Some of them act instantaneously, and the effects of most of them are in general fully developed within an hour or little more. But this character is by no means uniform. The most violent may be made to act, so as to bring on their peculiar symptoms slowly, or even by imperceptible degrees. Thus arsenic, which usually causes violent symptoms from the very beginning, may be so administered as to occasion at first nothing more than slight nausea and general feebleness; and afterwards in slow succession its more customary effects. In like manner corrosive sublimate may be given in such a way as to cause at first mild salivation, and finally gangrene of the mouth. Even many vegetable poisons might be administered in the same way. The well-known consequences of digitalis in medicinal doses will serve as a familiar instance. A still better illustration is supplied by the medicinal effects of the alkaloid of nux-vomica, whose action in other circumstances is most rapid and violent: Strychnia in a moderate dose will cause death by violent tetanus in two or three minutes; but when given in frequent small doses as a remedy in palsy, it has been known to bring on first starting of the limbs, then stiffness of the jaw, afterwards pain and rigidity of the neck; and these effects might be increased so gradually, that the patient would seem to die under ordinary tetanus. Nevertheless, the foregoing considerations being kept always in mind, it still remains true, that the effects of poisons for the most part begin suddenly, when the dose is large. This is an important circumstance in regard to certain active poisons, such as the mineral acids, oxalic acid, arsenic, strychnia, &c. For when it is considered that in criminal cases they are given for the most part in unnecessarily large doses, it follows that if the effect ascribed to these poisons in such doses have not begun suddenly, the suspicion is probably incorrect.

The same remarks may be applied to the sudden termination of the symptoms. Poison is for the most part given criminally in doses so large that it proves rapidly fatal. Yet this is not always the case; the diseased state occasioned by poisons has often been prolonged, as will be seen hereafter, for several weeks, sometimes for several months; nay, a person may be carried off by a malady, the seeds of which have been sown by the operation of poison years before.

The present would be the proper place for noticing the important question regarding the interval of time, after which, if death supervenes, it cannot be laid to the charge of the person who administered the poison. It is unnecessary, however, to say much on the subject. According to the English law, death must take place within a year. As to the Scottish law, it may be inferred from what has been said by the late Baron Hume on the subject of homicide generally, that a charge of poisoning is relevant although the person should die at a period indefinitely remote, and that it will infer the pains of law, provided the operation of the poison can be distinctly traced, unmodified by extraneous circumstances, from the commencement of the symptoms to the fatal termination.[^[69]] Of course the influence of these modifying circumstances in lessening the criminal’s responsibility will increase with the interval. The question for the medical jurist to determine in such a case would therefore be, the distance of time to which death may be delayed in the case of poisoning generally, and in that of the particular poison. This question cannot be answered even with an approach to precision, except in the instance of a few common poisons. Most vegetable and animal poisons prove fatal either in a few days or not at all; but some mineral poisons may cause death after an interval of many days. It appears probable that arsenic may cause death after an interval of several months, and it is well ascertained that the symptoms of poisoning with the mineral acids have continued uninterruptedly and without modification for eight months, and then terminated fatally.

2. The next general characteristic of the symptoms of poisoning is regularity in their increase. It is clear, however, that even this character cannot be universal. For in all cases of slow poisoning by repeated small doses there must be remissions and exacerbations, just as in natural diseases. Besides, as we can seldom watch the symptoms advancing in their simple form, but must endeavour to remove them by remedies, remissions may thus be produced and their tendency to increase steadily counteracted. Farther, some poisons admit of exacerbations and remissions, even when given in one large dose; and there are others, the very essence of whose action is to produce violent symptoms in frequent paroxysms. Of the latter kind are nux vomica, and the other substances that contain strychnia. Of the former kind is arsenic: in cases of poisoning with arsenic it often happens, that after the first five or six hours have been passed in great agony, the symptoms undergo a striking remission for as many hours, and then return with equal or increased violence. Still it is true that on the whole the symptoms of poisoning are steady in their progress; so that this should always be attended to as one of the general characters. In the case of slow poisoning, too, when the most remarkable deviations from it are observed, the very occurrence of exacerbations and remissions, combined with certain points of moral proof, may furnish the strongest evidence possible. Thus, on the trial of Miss Blandy at Oxford in 1752, for the murder of her father, one of the strongest circumstances in proof was, that repeatedly after she gave the deceased a bowl of gruel, suspected to be poisoned, his illness was much increased in violence.[^[70]]

As connected with the present subject, a question might here be noticed that has been discussed on the occasion of various trials, namely, whether the symptoms of poisoning are susceptible of a complete intermission. It cannot be answered satisfactorily, however, except with reference to particular poisons. The property alluded to has been ascribed to several poisons, even to mercury, arsenic, and opium; but oftener, I believe, in consequence of an improper desire on the part of the witness to prove or to perfect their view of the case, than through legitimate induction from facts.

3. Another characteristic is uniformity in the nature of the symptoms throughout their whole progress. This character is the least invariable of them all; for many poisons cause very different symptoms towards the close from those which they cause at the beginning. Arsenic may induce at first inflammation of the alimentary canal, and afterwards palsy or epilepsy; nux-vomica may excite at first violent tetanus, and afterwards inflammation of the stomach and bowels; and corrosive sublimate, after exciting in the first instance inflammation, may prove eventually fatal by inducing excessive ptyalism. In truth, certain changes of this kind in the nature of the symptoms will, in special cases, afford strong presumption, perhaps absolute proof, not only of general poisoning, but even also of the particular poison given. The reason for mentioning so uncertain a character as uniformity in the nature of the symptoms among their characteristics will appear presently.—[pp. [47] & [50].]

4. The fourth characteristic is, that the symptoms begin soon after a meal, or rather, soon after food, drink, or medicine has been taken. The occasions on which we eat and drink are so numerous and so near one another, that unless the poison suspected is one which acts with rapidity, it may be difficult to attach any weight to this circumstance. Some poisons rarely produce their effects till a considerable time after they are swallowed; the poisonous mushrooms, for example, may remain in the alimentary canal for several hours or even an entire day and more, before their effects begin; poisonous cheese in like manner may not act for five or six hours,[^[71]] or even a whole day;[^[72]] and that kind of cholera, which is caused in some people by putrid, diseased, and new-killed meat, seldom begins, so far as I have observed, till twelve hours or more after the noxious meal. With regard to the commoner poisons, such as arsenic, corrosive sublimate, the mineral acids, oxalic acid, nux-vomica, and the like, it is a good general rule, that the symptoms, if violent from the beginning, must have begun soon after food, drink, or medicine has been taken.

In making inquiries respecting this point, however, care must be taken not to lose sight of certain circumstances which may cause a deviation from the general rule.

In the first place, it should be remembered that poisons may be administered in many other ways besides mixing them with articles of food or drink, or substituting them for medicines. They may be introduced into the anus; they have been introduced into the vagina; they have also been introduced by inhalation in the form of vapour; and there can be no difficulty in introducing some of them through wounds.

Secondly, another circumstance which may be kept in view is, that, if a person falls asleep very soon after swallowing a poison, especially one of the irritants, the commencement of the symptoms may be considerably retarded, provided it be not one of the powerful corrosives. This statement is not so fully supported by facts as to admit of its being laid down with confidence as a general rule. But from various incidents which have come under my notice it appears not improbable, that sleep does possess the power of putting off for a while the action of some poisons. In particular some instances have occurred to me where arsenic taken at night did not begin to act for several hours, the individual having in the meantime been asleep.[^[73]] The occurrence of so long an interval between its administration and the first appearance of the symptoms is so contrary to what generally happens, that some cause or another must be in activity; and the insensibility of the system during sleep to most sources of excitement seems to supply a sufficient explanation. The slow operation of laxatives during sleep compared with their effects during one’s waking hours, is an analogical fact.

A third consideration to be attended to is, that poison may be secretly administered during sleep to a person who lies habitually with his mouth open. This is fully proved by an interesting case which will be noticed under the head of the moral evidence of poisoning. In that particular case the individual immediately awoke, because the poison was concentrated sulphuric acid; but it may admit of question whether a sound sleeper might not swallow less irritating poisons without being awakened. In such circumstances no connexion of course could be traced between the taking of a suspected article and the first appearance of the symptoms.

5. Lastly, the symptoms appear during a state of perfect health. This is an important character, yet not universal; for it cannot be expected to apply to cases of slow poisoning, and poisons may be given while the person is actually labouring under natural disease. Cases of the last description are generally very embarrassing; for if, instead of medicine, a poison be administered, whose symptoms resemble the natural disease, suspicion may not arise till it is too late to collect evidence.

It must be apparent from the preceding observations, that the characters common to the symptoms of general poisoning are by no means universally applicable. Yet on reviewing them attentively it will also appear, that, considering the little knowledge possessed by the vulgar of the action of poisons, and consequently the rude nature of their attempts to commit murder by poisoning, the exceptions to the general statements made above will not be numerous.

It now remains to be seen how far these characters distinguish the symptoms of poisoning from those of natural disease; and

1. As to the suddenness of their invasion and rapidity of their progress, it is almost needless to observe, that many natural diseases commence with a suddenness and prove fatal with a rapidity, which few or no poisons can surpass. The plague may prove instantaneously fatal; and even the continued fever of this country may be fully formed in an hour, and may terminate fatally, as I have once witnessed, at the beginning of the second day. Inflammation of the stomach also begins suddenly and terminates soon. Cholera likewise answers this description: I have known the characters of ordinary cholera fully developed within an hour after the first warning symptom, and frequently in hot climates, nay, in some rare instances even in Britain, it proves fatal in a few hours. Malignant cholera frequently proves fatal in a few hours. Inflammation of the intestines, too, may begin, or at least seem to begin, suddenly and end fatally in a day: One variety of it, now well known to affect the mucous membrane, may remain quite latent till the gut is perforated by ulceration, and then the patient is attacked with acute pain, vomiting, and mortal faintness, and frequently perishes within twenty-four hours.[^[74]] But in particular many organic diseases of the heart prove suddenly fatal, without any previous warning; and this is also true to a certain extent even of apoplexy; for, as will afterwards be seen, it is an error to suppose that apoplexy is always, or even generally, preceded by warning symptoms. The first characteristic, therefore, as applied to the symptoms of poisoning generally, contrasted with those of general disease, must appear by no means distinctive. But opportunities will occur afterwards for showing, that it is sometimes a good diagnostic in the case of particular poisons.[^[75]]

2. As to the uniformity or uninterrupted increase of the symptoms, it is equally the attribute of many common diseases. I am not aware, that in speedily fatal cases of the internal phlegmasiæ a considerable remission is often observed. Apoplexy, too, very frequently continues its course without interruption; and the same may be said of cholera, and indeed of most acute diseases, when they prove rapidly fatal.

3. It was stated above, that the third character, uniformity in kind throughout their progress, is by no means an invariable circumstance. Still less is it distinctive; for many diseases are marked by great uniformity of symptoms. It has been enumerated nevertheless among the general characters of poisoning, because, although its presence can hardly ever add any weight to the evidence in favour of death by poison, its absence may sometimes afford even positive proof in favour of natural death. That is, changes of a certain kind occurring in the symptoms during their progress may be incompatible with the known effects of a particular poison or of all poisons, and capable of being accounted for only on the supposition of natural disease having been at least the ultimate cause of death. This statement, which is one of some importance, is illustrated by a pointed case, that of Charles Munn, mentioned at the close of the present section.

4. In the next place, it was observed that some reliance may be placed on the fact, that the symptoms of poisoning appear very soon after a meal. But we also know this to be the most frequent occasion on which some natural disorders begin. An attack of apoplexy after a hearty meal is a common occurrence. That kind of cholera which follows the immoderate use of acid fruit likewise comes on soon after eating. Sometimes mere excessive distension of the stomach after a meal proves suddenly or instantaneously fatal. Drinking cold water when the body is over-heated likewise causes at times immediate death. It appears that perforation of the stomach, the result of an insidious ulcer of its coats, and likewise rupture of the stomach from mechanical causes, are most apt to occur during the digestion, and therefore soon after the taking of a meal.

These few observations will make it evident that the appearing of violent symptoms soon after eating may arise from other causes besides the administration of poison. At the same time, as the diseases which are apt to commence suddenly at that particular time are few in number, and none of them by any means frequent, it is always justly reckoned a very suspicious circumstance; and when combined with certain points of moral proof, such as that several people, who have eaten together, were seized about the same time with the same kind of symptoms, the evidence of general poisoning becomes very strong indeed. Sometimes the evidence from the date of their commencement after a meal may singly supply strong evidence, as in the case of the mineral acids and alkalis, or corrosive sublimate, which begin to act in a few seconds or minutes.

On the other hand, if the symptoms do not begin soon after food, drink, or medicine has been taken (the circumstances being such as to exclude the possibility of poison being introduced by a wound, by the lungs, or by any other channel but the stomach), the presumption on the whole is against poisoning; and sometimes the evidence to this effect may be decisive. The principle now propounded may be often a very important one in the practice of medical jurisprudence; for when united with a little knowledge of the symptoms antecedent to death, it may be sufficient to decide the nature of the case. Thus it is sufficient, in my opinion, to decide the celebrated case of the Crown Prince of Sweden. The prince, while in the act of reviewing a body of troops on the 28th May, 1810, was observed suddenly to waver on his horse; and soon afterwards he fell off while at the gallop, was immediately found insensible by his staff, and expired in half an hour. As he was much beloved by the whole nation, a rumour arose that he had been poisoned; and the report took such firm root in the minds of all ranks, that a party of military, while escorting the body to Stockholm, were attacked near the city by the populace, and their commander, Marshal Fersen, murdered; and Dr. Rossi, the prince’s physician, after narrowly escaping the same fate, was in the end obliged to quit his native country. Now, no other poison but one of the most active narcotics could have caused such symptoms, and none of them could have proved so quickly fatal unless given in a large dose. It was proved, however, that on the day of his death the prince had not taken any thing after he breakfasted; and an interval of nearly four hours elapsed after that till he fell from his horse. This fact alone, independently of the marks of apoplexy found in the head after death, and the warning symptoms he repeatedly had, was quite enough to show that he could not have died of poison, as it was incompatible with the known action of the only poisons which could cause the symptoms. This is very properly one of the arguments used by the Medical Faculty of Stockholm, which was consulted on the occasion.[^[76]]

The same circumstances will often enable us to decide at once a set of cases of frequent occurrence, particularly in towns,—where the sudden death of a person in a family, the members of which are on bad terms with one another, is rashly and ignorantly imputed to poison, without any particular poison being pointed at; and where, consequently, unless the morbid appearances clearly indicate the cause of death, a very troublesome analysis might be necessary. In several cases of this kind, which have been submitted to me, I have been induced to dispense with an analysis by resting on the criterion now under consideration. The following is a good example.

A middle-aged man, who had long enjoyed excellent health, one afternoon about two o’clock returned home tired, and after having been severely beaten by his wife went to bed. At a quarter past two one of his workmen found him gasping, rolling his eyes, and quite insensible; and he died in a few minutes. As his wife had often maltreated and threatened him, a suspicion arose that he had died of poison, and the body was in consequence examined judiciously by Sir W. Newbigging and myself. The only appearance of disease we could detect was a considerable tuberculation of the septum cordis and anterior parietes of both ventricles. This disease might have been the cause of death; for there is no disease of the heart which may not remain long latent, and prove fatal suddenly. But, as the man never had a symptom referrible to disease of the heart, it was impossible to infer, in face of a suspicion of poisoning, that it must have been the cause of death; since the man might very well have died of poison, the disease of the heart continuing latent. Poisoning, however, was out of the question. The man had taken nothing whatever after breakfasting about nine. Now no poison but one of the most active narcotics in a large dose could cause death so rapidly as in this case; and the operation of such a poison in such a dose could not be suspended so long as from nine till two. An analysis was therefore unnecessary.

5. Little need be said with regard to the symptoms beginning, while the body is in a state of perfect health; because in truth almost all acute diseases begin under the same circumstances. Connected with this subject, however, a point of difference should be noticed which may be of use for distinguishing poisoning by the irritants from acute diseases of the inflammatory kind:—the latter rarely begin without some adequate and obvious natural cause.

On considering all that has now been said regarding the characteristics of the symptoms of general poisoning, as contrasted with those of natural disease, no one can hesitate to allow, that from them alone a medical jurist can never be entitled to pronounce that poisoning is certain. At the same time he must not on that account neglect them. For, in the first place, they are of great value as generally giving him the first hints of the cause of mischief, and so leading him to search in time for better evidence. Next, they will often enable him to say that poisoning was possible, probable, or highly probable; which, when the moral evidence is very strong, may be quite enough to decide the case. Thirdly, although they can never entitle him to say that poisoning was certain, they will sometimes enable him to say, on the contrary, that it was impossible. And to conclude, when the chemical or moral evidence proves that poison was given, the characters of the symptoms may be necessary to determine whether it was the cause of death.

As the last statement is one of consequence, and yet has been overlooked by some authors on medical jurisprudence in this country, it may be illustrated by one or two comments. It does not follow, because a poison has been given, that it is the cause of death; and therefore in every medico-legal inquiry the cause of the first symptoms and the cause of death should be made two distinct questions. The question, whether a poison, proved to have been administered, was the cause of death, is to be answered by attending to the second and third characteristics mentioned above, and considering whether the symptoms went on progressively increasing, or altered their nature during the course of the patient’s illness, and whether the alteration, if any, was such as may occur in the case of poisoning generally, or of the special poison given. These remarks are very well exemplified by a case, of which I have related the particulars elsewhere,[^[77]] that, namely, of Charles Munn, tried at the Inverary Spring Circuit of 1824 for the double crime of procuring abortion, and of murder by poisoning. The moral evidence and symptoms together left no doubt that arsenic had been given, and that the deceased, a girl with whom the prisoner cohabited, laboured under the effects of that poison in a very aggravated and complex form for twelve days. After that she began to recover rapidly, and in the course of a fortnight more was free of every symptom except weakness and pains in the hands and feet: In short, all things considered, she was thought to be out of danger. But she then became affected with headache and sleeplessness, and died in nineteen days more under symptoms of obscure general fever, without any local inflammation. Dr. Duncan, junior, and I, who were consulted by the Crown in this case, were of opinion,—that granting the girl’s first illness, as appeared from moral and medical evidence, was owing to arsenic, her death could not be ascribed to it with any certainty. It is true that in a few instances the primary irritant symptoms caused by arsenic have been known to pass into an obscure general fever, which has ended fatally; and that this mode of termination coincides with the effects ascribed to arsenic as the chief ingredient in the celebrated Aqua Toffana. But the latter phenomena, at best of doubtful authenticity, are not represented to have been preceded by the ordinary symptoms of violent irritation, or to have been developed except under the use of continuous small doses; and as for the more recent and less ambiguous cases of fever succeeding the usual primary effects of a large dose, in no instance yet recorded was there an intermission between the two stages.

So much, then, for the force of the evidence drawn from the characters of the symptoms of general poisoning. According to the example of others, I might consider in the present place the force of evidence derived from the symptoms themselves, which distinguish the three classes of poisons. But this subject, together with the special natural diseases which imitate the symptoms of poisoning, will be treated of more conveniently as an introduction to each of the classes.

Section II.—Of the Evidence from Morbid Appearances.

The appearances left in the dead body after death by poison used formerly to be relied on as strongly as the symptoms during life; and with even less reason. Except in the instance of a very few poisons, the morbid appearances alone can never distinguish death by poison from the effects of natural disease, or from some other kinds of violent death. There is not much room, therefore, for general remarks under the present head.

It was at one time thought by the profession, and is still very generally imagined by the vulgar, that unusual blackness or lividity of the skin, indicates death by poison generally. But every experienced physician is now well aware, that excessive lividity is by no means universally produced by poison, and that it is likewise produced by so many natural diseases as not even to form, in any circumstances whatever, the slightest ground of suspicion. Neither is there any difference in kind, as some imagine, between the lividity which succeeds death by poison, and that which follows natural death. Yet it is right for the medical jurist to be aware that lividity as a supposed consequence of poison ought to be strictly attended to by medical inspectors and law officers while investigating charges of poisoning, because the vulgar belief on the subject sometimes leads to such conduct or language on the part of the poisoner as betrays his secret at the time, and constitutes evidence of his guilt afterwards.

Another appearance equally unimportant is early putrefaction of the body. Early putrefaction, at one time much insisted on as a criterion of poisoning,[^[78]] cannot even justify suspicion. It is by no means invariably, or even generally caused by poisons; nay, sometimes a state precisely the reverse appears to be induced;[^[79]] and it is seen quite as frequently after natural death.

Some other appearances, not more conclusive, might also be mentioned here; but they belong properly to the effects of individual poisons, or of classes of poisons, not to those of poisoning generally. It may merely be remarked at present, therefore, that the appearances after death, which are really morbid, and which may be produced by poisons, are, in one great class, the signs of inflammation of the alimentary canal in its progressive stages,—in another class, the signs of congestion within the head,—and in a third, a combination of the effects of the two preceding classes; that neither set of appearances is invariably caused by the poisons which usually cause them; that congestion within the head is really seldom produced by those which are currently imagined to produce it; and that most of the appearances of both kinds are exactly similar to those left by many natural diseases.

But although, on the whole, the appearances after death, when considered singly, can seldom supply evidence of poisoning even to the amount of probability, they may nevertheless prove very important under other points of view. Thus, in connection with the symptoms and the general evidence, the appearances after death may furnish decisive proof; and even should the history of the symptoms be unknown, or have been unskilfully collected, the appearances after death, by pointing out the nature of the previous illness, may furnish evidence enough to decide the case, when the moral proof is strong. Again, in cases of alleged imputation of poisoning they are necessary to determine whether a poison actually found in the body was introduced during life or after death. Besides, the very absence of morbid appearances may afford presumptive proof in some circumstances,—when, for example, the question is, whether a person has died of apoplexy or of poisoning with narcotics? Farther, a few poisons, as was formerly stated, occasionally produce appearances so characteristic, as not to be capable of being confounded with the effects of any other agent whatsoever: It will be found hereafter, for example, that the mineral acids have at times left behind them in the dead body unequivocal evidence of their operation. And finally, in cases where no doubt can be entertained that poison was taken, the evidence from morbid appearances may be useful or necessary for settling whether or not it was the cause of death. Two pointed examples of this kind will be noticed under the next section.

When signs of the action of poison are not found in the dead body, and on the contrary marks are found of the operation of natural disease, the presumption of course is that the person died a natural death. But here a few words of caution must be added with regard to the drawing of that inference in cases where the history of the symptoms is not known. It does not follow merely because certain appearances of natural disease are found, that their cause was the cause of death. For death may have arisen from a totally different cause, such as poisoning. This remark is not, as some may imagine, the offspring of hypothetical refinement, but a necessary caution, drawn from actual and not unfrequent occurrences. Thus, for example, the following cases will show, that there may be found in the dead body diseased appearances, arising from pleurisy, hydrothorax, or peripneumony, sufficient to cause death, or to account for death in ordinary circumstances; and that nevertheless the disease may have been completely latent, and death have arisen from poison. In Rust’s Magazin is related the case of a German apothecary, who poisoned himself with prussic acid, and in whose body the lower lobe of the left lung was found consolidated and partly cartilaginous.[^[80]] In Corvisart’s Journal an army-surgeon has described the case of a soldier, who died of a few hours’ illness, and whose right lung was found after death forming one entire abscess; yet to the very last day of his existence he daily underwent all the fatigues of a military life; and in fact he died of poisoning with hemlock.[^[81]] In Pyl’s Memoirs and Observations, there is a similar account of a woman who enjoyed tolerable health, and died during a fit of excessive drinking, and in whose body the whole left lung was found one mass of suppuration.[^[82]] Under the next section will be mentioned other equally pointed cases of death by poison, where the apparent cause of death was external violence.

The conclusions to be drawn from these facts are that, at all events, the medical inspector in a question of poisoning, must take care not to be hurried away by the first striking appearances of natural disease which he may observe, and so be induced to conduct the rest of the inspection superficially; and likewise, that he should not so frame his opinion on the case, as to exclude the possibility of a different cause from the apparent one, unless the appearances are such as must necessarily have been the cause of death. It may be said, that in requiring this condition for an unqualified opinion, a rigour of demonstration is exacted, which can rarely be attained in practice. But, on the one hand, it must not be forgotten, that an unqualified opinion is not always necessary; and on the other hand, although it were, I think it might be shown, if the subject did not lead to disproportionate details, that we may often approach very near the rigour of demonstration required. At present no more need be said, than that the inspector should be particularly on his guard in those cases, in which the appearances, though belonging to the effects of a deadly disease, are trifling; and still more in those in which the appearances, though great, belong to the effects of a disease, whose whole course may be latent. And I may add, that, from what I have observed of medico-legal opinions, the caution now given is strongly called for.

It may be right to allude here also to another purpose which may be served by a careful consideration of the morbid appearances. In cases in which the history of the symptoms is unknown or imperfect the extent and state of progress of the appearances will sometimes supply strong presumptive evidence of the duration of the poisoning. This is an obvious and important application of the knowledge of the pathology of poisoning; but the simple mention of it is all which can be here attempted, as special rules can hardly be laid down on the subject.

Section III.—Evidence from Chemical Analysis.

The chemical evidence in charges of poisoning is generally, and with justice, considered the most decisive of all the branches of proof. It is accounted most valid, when it detects the poison in the general textures of the body, or in the blood, or in the stomach, intestines or gullet, then in the matter vomited, next in articles of food, drink or medicine of which the sufferer has partaken, and lastly, in any articles found in the prisoner’s possession, and for which he cannot account satisfactorily.

When poison is detected in any of these quarters, more especially in the stomach or intestines, it is seldom that any farther proof is needed to establish the fact of poisoning. In two circumstances, however, some corroboration is necessary.

In the first place, in cases where a defence is attempted by a charge of imputation of poisoning it may be necessary to determine by an accurate account of the symptoms, or by the morbid appearances, or by both together, whether the poison was introduced into the body before or after death. For it is said, that attempts have been made to impute crime by introducing poison into the stomach or anus of a dead body; and although I have not been able to find any authentic instance of so horrible an act of ingenuity having been perpetrated, it must nevertheless be allowed to be quite possible.

Secondly, an account of the symptoms and morbid appearances is still more necessary, when the question at issue is, not so much whether poison has been given, as whether it was the cause of death, granting it had been taken. Some remarks have been already made on this question in the two former sections. In the present place some farther illustrations will be added from two very striking cases. They are interesting in many respects, and particularly as showing the importance of strict medico-legal investigation: I am almost certain that but a few years ago their real nature would not have been discovered in this country. The first to be noticed occurred to Dr. Wildberg of Rostock. Wildberg was required to examine the body of a girl, who died while her father was in the act of chastising her severely for stealing, and who was believed by all the bye-standers, and by the father himself, to have died of the beating. Accordingly, Wildberg found the marks of many stripes on the arms, shoulders and back, and under some of the marks blood was extravasated in considerable quantity. But these injuries, though severe, did not appear to him adequate to account for death. He therefore proceeded to examine the cavities; and on opening the stomach, he found it very much inflamed, and lined with a white powder which proved on analysis to be arsenic. It turned out, that on the theft being detected the girl had taken arsenic for fear of her father’s anger, that she vomited during the flogging, and died in slight convulsions. Consequently, Wildberg very properly imputed death to the arsenic. In this case the chemical evidence proved that poison had been taken; but an account of the symptoms and appearances was necessary to prove that she died of it.[^[83]] The other case occurred to Pyl in 1783. A woman at Berlin, who lived on bad terms with her husband, went to bed in perfect health; but soon afterwards her mother found her breathing very hard, and on inquiring into the cause discovered a wound in the left side of the breast. A surgeon being immediately sent for, the hemorrhage which had never been great, was checked without difficulty; but she died nevertheless towards morning. On opening the chest it appeared that the wound pierced into it, and penetrated the pericardium, but did not wound the heart; and although the fifth intercostal artery had been divided, hardly any blood was effused into the cavity of the chest. Coupling these circumstances with the trifling hemorrhage during life, and the fact that she had much vomiting, and some convulsions immediately before death, Pyl satisfied himself that she had not died of the wound: and accordingly the signs of corrosion in the mouth and throat, and of irritation in the stomach, with the subsequent discovery of the remains of some nitric acid in a glass in her room, proved that she had died of poison.[^[84]]

Causes of the disappearance of poison from the body.—Chemical evidence is not always attainable in cases of poisoning. Various causes may remove the poison beyond reach. Hence although poison be not detected in the body,—the experimenter being supposed skilful and the poison of a kind which is easily discovered,—still it must not be concluded from that fact alone that poison has not been the cause of death. For that which was taken into the stomach may have been all discharged by vomiting and purging, or may have been all absorbed, or decomposed; and that which has been absorbed into the system may have been all discharged by the excretions.

1. It may have been discharged by vomiting and purging. Thus on the trial of George Thom for poisoning the Mitchells, held at Aberdeen at the Autumn Circuit of 1821, it was clearly proved, that the deceased had died of poisoning by arsenic; yet by a careful analysis none could be detected in the stomach or its contents; for the man lived seven days, and during all that time laboured under frequent vomiting.[^[85]] In a remarkable case related by Dr. Roget, arsenic could not be found in the matter vomited twenty-four hours after it had been swallowed;[^[86]] in another related by Professor Wagner of Berlin, that of an infant who died in twelve hours under incessant vomiting after receiving a small quantity of arsenic, none could be detected in the stomach;[^[87]] in another which I have described in a paper on arsenic, although the person lived only five hours, the whole arsenic which could be detected in the tissues and contents of the stomach did not exceed a fifteenth part of a grain;[^[88]] in an American Journal there is a striking case of a grocer, who died eight hours after swallowing an ounce of arsenic, and in whose body none could be found chemically,—at a period however antecedent to the late improvements in analysis;[^[89]] and in a case communicated to me not long ago by Mr. Hewson of Lincoln, where arsenic was given in solution, and death ensued in five hours, none of the poison could be detected either in the contents or tissues of the stomach by a careful analysis conducted according to the most modern principles.

Nevertheless, it is singular how ineffectual vomiting proves in expelling some poisons from the stomach. Those which are not easily soluble, and have been taken in a state of minute division, may remain adhering to the villous coat, notwithstanding repeated and violent efforts to dislodge them by vomiting. Many instances to this effect have occurred in the instance of arsenic. Metzger has related a case, where, after six hours of incessant vomiting, three drachms were found in the stomach.[^[90]] Mr. Sidey, a surgeon of this city, has mentioned to me an instance of poisoning with king’s yellow, in which he found the stomach lined with the poison, although the patient had vomited for thirty hours. In three cases which I have investigated arsenic was detected, although the people lived and vomited much for nearly two days;[^[91]] and Professor Orfila has noticed a similar instance in which that poison was found in the contents of the stomach, although the person had vomited incessantly for two entire days.[^[92]]

It is not easy to specify the period after which a poison that has excited vomiting need not be looked for in the stomach. It must vary with a variety of circumstances whose combined effect it is almost impossible to appreciate, such as the solubility and state of division of the poison, the frequency of vomiting, the substances taken as remedies, and the like. When the poison is in solution and the patient vomits much, an analysis may be expected to prove frequently abortive, even though the individual survives but a few hours, as in Mr. Hewson’s case already noticed. In other circumstances, however, as various facts quoted above will show, poisons may frequently be found after two days incessant vomiting; and on the whole it may be stated, that the recent improvements in analysis render the period much longer than it has generally been, and would naturally be imagined. Metzger has related the case of a woman poisoned with arsenic mixed with currants, in whose body, after eight days of frequent vomiting, he found ten or twelve currants, which gave out an odour of garlic when burnt;[^[93]] but here the dose, if there was really arsenic, must have been repeated recently before death, for it is not possible to conceive how currants could remain in the stomach so long, whatever may be thought of the possibility of arsenic remaining. It is farther proper to add, that Professor Henke of Erlangen, one of the highest living authorities in Germany, once found grains of arsenic in the gullet, although he found none in any other part of the body, of a person who survived the taking of the poison four days.[^[94]] Allowing to this fact all the weight derived from the high name of its author, I must nevertheless express great doubt whether the arsenic was not repeated more recently before death.

2. The poison may have disappeared, because it has been all absorbed. It has several times happened that in the bodies of those poisoned with laudanum, or even with solid opium, none of the drug could be detected after death. Sometimes indeed it is found, even though the individual survived the taking of the poison many hours. Thus a case related by Meyer of Berlin, in which the person lived ten hours after taking the saffron-tincture of opium; and nevertheless it was detected in the stomach by a mixed smell of saffron and opium.[^[95]] But more commonly it all disappears, unless the dose has been very large. In a case of poisoning with laudanum, which I examined here along with Sir W. Newbigging in 1823, none could be detected, although strong moral circumstances left no doubt that laudanum had been swallowed seven or eight hours before death. An instance of the same kind has been minutely related by Pyl. It was that of an infant who was poisoned with a mixture of opium and hyoscyamus, and in whose stomach and intestines none could be detected by the smell.[^[96]] Similar observations have been often made on animals; and several additional cases of the same purport, occurring in man, will be related under the head of opium.

It might be of use to quote some of the numerous errors committed by medical witnesses, in consequence of having overlooked the effect of absorption in removing poisons beyond the reach of chemical analysis. But not to be too prolix, I shall be content with mentioning a single very distinct case in point, which happened at a Coroner’s Inquest in London, in 1823. A young man one evening called his fellow-lodger to his bedside; assured him he had taken laudanum, and should be dead by the morrow; and desired him to carry his last farewell to his mother and his mistress. His companion thought he was shamming; but next morning the unfortunate youth was found in the agonies of death. The moral evidence was not very satisfactory; but that is of little consequence to my present object. The point in the case I would particularly refer to is the declaration of the medical inspector, that laudanum could not have been taken, because he did not find any by the smell or by chemical analysis in the contents of the stomach.[^[97]]

3. Poisons may not be found, because the excess has been decomposed.

Vegetable and animal poisons may be altogether destroyed by the process of digestion. This observation will explain why sometimes no poison could be found in cases of poisoning with crude opium or other vegetable solids. A French physician, M. Desruelles, has related the case of a soldier, who died six hours and a half after swallowing two drachms of solid opium, and in whose stomach nothing was found but a yellowish fluid, quite destitute of the smell of the drug.[^[98]]

Some mineral poisons, such as corrosive sublimate, lunar caustic, and hydrochlorate of tin, are also decomposed in the stomach. But they are not removed beyond the reach of chemical analysis. The decomposition is the result of a chemical, not of a vital process; and the basis of the poison may be found in the solid contents of the stomach under some other compound form. Other poisons again may be apt to elude detection by altering their form, by combining with other substances, without themselves undergoing decomposition. Thus it appears from a case related by Mertzdorff of Berlin, that, in poisoning with sulphuric acid, after the greater part of the poison is discharged by vomiting, the remainder may escape discovery by being neutralized: For, although he could not find any free acid in the contents of the stomach, he discovered 4½ grains in union with ammonia by precipitation with muriate of baryta.[^[99]]

It may be also right to mention another kind of decomposition which may render it impossible to detect a poison that has been really swallowed—namely, that arising from decay of the body. In several recent cases bodies have been disinterred and examined for poison months or even years after death. In these and similar cases it would be unreasonable to expect always to find the poison, even though it existed in the stomach immediately after death. Some poisons, such as oxalic acid, might be dissolved and then exude; others, such as the vegetable narcotics, will undergo putrefaction; and others, such as prussic acid, are partly volatilized, partly decomposed, so as to be undistinguishable in the course of a few days only. The mineral poisons, those at least which are solid, are not liable to be so dissipated or destroyed. Some authors, indeed, have said that arsenic may disappear in consequence of its uniting with hydrogen disengaged during the progress of putrefaction, and so escaping in the form of arseniuretted-hydrogen gas; and they have endeavoured to account in this way for the non-discovery of it in the bodies of the people who had been killed by arsenic, and disinterred for examination many months afterwards.[^[100]] But the supposition is by no means probable: at least arsenic has been detected in the body fourteen months, nay, even seven years, after interment. For farther details, on this curious topic, the reader may turn to the article Arsenic.

On the whole, the result of the most recent researches is that the effect of the spontaneous decay of dead animal matter in involving poisons in the general decomposition appears to be much less considerable than might be anticipated. For this most important medico-legal fact, the toxicologist is indebted to the experimental inquiries of MM. Orfila and Lesueur.[^[101]] The poisons tried by them were—sulphuric and nitric acids, arsenic, corrosive sublimate, tartar-emetic, sugar of lead, protomuriate of tin, blue vitriol, verdigris, lunar caustic, muriate of gold, acetate of morphia, muriate of brucia, acetate of strychnia, hydrocyanic acid, opium, and cantharides. They found that after a time the acids become neutralized by the ammonia disengaged during the decay of animal matter;—that by the action of the animal matter the salts of mercury, antimony, copper, tin, gold, silver, and likewise the salts of the vegetable alkaloids, undergo chemical decomposition, in consequence of which the bases become less soluble in water, or altogether insoluble;—that acids may be detected after several years’ interment, not always, however, in the free state;—that the bases of the decomposed metallic salts may also be found after interment for several years;—that arsenic, opium, and cantharides undergo little change after a long interval of time, and are scarcely more difficult to discover in decayed, than in recent animal mixtures;—but that hydrocyanic acid disappears very soon, so as to be undistinguishable in the course of a few days.

4. Lastly, the poison which has been absorbed into the system, and may consequently be detected in certain circumstances in the textures of the body at a distance from the alimentary canal, may also be removed beyond the reach of analysis, by being gradually discharged along with the excretions. It has been fully proved in recent times, that in poisoning with arsenic the poison may be found in ordinary cases, for some days after being swallowed, in the liver especially, but also in the other textures, in the blood, and in the urine; but that if a flow of urine be established and kept up, in nine or ten days, and sometimes much sooner, it can no longer be discovered anywhere by the nicest analysis.[^[102]]

Is the discovery of poison in the body or the evacuations essential to establish a charge of poisoning? It was mentioned at the commencement of the present section, that the chemical evidence is generally, and correctly, considered the most decisive of all the branches of proof in cases of poisoning. But some toxicologists have even gone so far as to maintain that without chemical evidence, or rather, in more general terms, without the discovery of poison either in the body itself or in the evacuations,—no charge of poisoning ought to be held as proved. This, however, is a doctrine to which I cannot assent. In the preceding observations on the evidence of general poisoning it has been several times alluded to as unsound; and repeated opportunities of establishing exceptions will occur in the course of this work, under the head of individual poisons. At present it may be well to illustrate its unsoundness in reference to those charges of poisoning, where no particular poison is pointed at by the medical evidence, but where a whole class of poisons must be kept more or less in view. Even here I apprehend there may be sufficient evidence in the symptoms and morbid appearances, without any chemical facts,—to render poisoning so highly probable, that in conjunction with strong moral evidence, no sensible man can entertain any doubt on the subject. Several illustrations might be here given; and some will be found scattered throughout the work. In the present place a few instances will be mentioned which cannot be conveniently arranged any where else, and which are well worthy of notice, as being striking examples of the decision of questions of poisoning without chemical evidence.

A man of doubtful character and morals, well acquainted with chemistry and medical jurisprudence, and of disordered finances, was known to harbour a design on a friend’s wife, who possessed a considerable fortune. At last he one morning invited the husband to breakfast with him at a tavern; and they breakfasted, in a private apartment, on beef-steaks, fried potatoes, eels, claret, and rum. They had scarcely commenced the meal when his guest complained of feeling unwell; and soon afterwards he vomited violently. This symptom continued, along with excruciating pain in the belly, for a long time before the prisoner sent for medical aid; indeed he did not procure a physician till the sufferer had been also attacked with very frequent and involuntary purging. The physician, who, before seeing his patient, had received the prisoner’s explanation of the apparent cause of the illness, was led at first to impute the whole to cholera caught by exposure to cold; but on returning at seven in the evening, and finding the gentleman had been dead for an hour, he at once exclaimed that he had been poisoned. On the body being inspected much external lividity was found, contraction of the fingers, and great inflammation of the stomach and intestines, presenting an appearance like that of gangrene.[^[103]] On analyzing some fluid left in the stomach, no arsenic or other poison could be detected. The attention of the inspectors was turned specially to arsenic, because the prisoner was proved to have bought that poison, and to have made a solution of some white powder in his kitchen not long before the deceased died. The prisoner in his defence stated, that the deceased had been for some time much weakened by the use of mercury, and while in this state was seized with cholera; and he likewise attempted to make it probable that the man, in despair at his not recovering from a venereal disease, might have committed suicide. The council of physicians who were required to give their opinion on the case state on the contrary, that the diseased was a healthy man, without any apparent disposition to disease; that there was no pretext whatever for supposing suicide; that the inflammatory state of the stomach and bowels supplied strong probability of poisoning with arsenic, but not certain evidence; that acute gastritis from natural causes is always attended with constipation; that the deceased presented symptoms of stupor and other signs of derangement of the nervous system remarked in rapid cases of poisoning with arsenic; that cholera is very rare at the end of November, the season when this incident occurred; and that the poison might well be discharged by vomiting. Although all the prisoner’s statements in defence were contradicted by satisfactory proof, and the medical evidence of poisoning was supported by a chain of the strongest general circumstances, the crime was considered by the court as not fully proved, because the prisoner could not be induced to confess, and because poison was not actually detected in the body. But on account of the very strong probability of his guilt, he was, in conformity with the strange practice of German courts in the like cases, condemned to fifteen years’ imprisonment.[^[104]] In this instance—considering the kind of symptoms, their commencement during a meal, the rapidity of death, the signs of violent inflammation in the stomach after so short an illness, and the facility with which the absence of poison in the contents of the stomach may be accounted for, more especially if it be supposed that the poison was administered in solution,—I consider the medical evidence of death by poisoning so very strong, that, the general evidence being also extremely strong, the prisoner’s guilt was fully demonstrated.

A case of the same kind, but of still greater interest, is that of Mary Anne M’Conkey, who was tried at the Monaghan Assizes in 1841 for the murder of her husband. I am indebted for the particulars to Dr. Geoghegan, one of the principal Crown witnesses. The prisoner who had been too intimate with another man, and had been heard to express her intention of getting rid of her husband, was observed one day before dinner to separate some greens for him from the plateful intended for the rest of the family. None of the latter suffered at all. But her husband was taken violently ill immediately after dinner, and died; and a neighbour accidentally present, who partook, though sparingly, of the same dish with him, was also similarly and violently affected but recovered. The deceased before finishing the greens said they had a disagreeable sharp taste, and was seized soon after with burning at the heart, tenderness at the pit of the stomach, vomiting, coldness, a sense of biting in the tongue and tingling through the whole flesh, excessive restlessness, occasional incoherence, locked-jaw, clenching of the hands, and frothing at the mouth; and he expired three hours after the meal. His neighbour, two minutes after finishing his greens, experienced a sense of pricking in the mouth and burning in the throat, gullet, and stomach; then salivation, a feeling of swelling in the face without actual fulness, general numbness and creeping in the skin; next excessive restlessness, coldness of the integuments, dimness of sight, and stupor; about an hour after the meal he became speechless, repeatedly fainted, frothed at the mouth, and clenched his hands; vomiting ensued, with considerable relief, and subsequently he had frequent attacks of it, with purging, tenderness of the epigastrium, cramps, and tingling in the flesh; and from these symptoms he recovered so slowly as to be unable to work for five weeks. The only morbid appearance of any note in the body of the deceased was a number of irregular brownish-black patches on the inside of the stomach. No poison could be detected in the contents or tissues of the stomach; none could be discovered in the house except a corrosive-sublimate solution which the prisoner used for a gargle; and none could be traced into her possession. A variety of circumstances of a general nature, which are passed over here for brevity, as not strictly appertaining to the present view of the case, threw very great suspicion over the prisoner. The medical witnesses deposed, that poisoning could alone explain the medical circumstances; and Dr. Geoghegan was of opinion that death was owing to some vegetable poison, although he could not specify the particular substance. He suspected, however, that it was monkshood. In these views, when consulted by him before the trial, I entirely concurred. Considering the taste observed by the deceased at the time he ate the greens, the rapidity with which he was taken ill afterwards, and the very peculiar symptoms, unlike those of any natural disease with which physicians are acquainted, and agreeing with those which are produced by monkshood,—considering also that another individual, who partook of the same dish with him, was similarly and simultaneously attacked, and with a severity proportioned to the quantity he took, while other persons who ate the same food from a different dish, did not suffer at all,—it appears to me that poisoning was clearly established; and I also think that the general evidence brought home the charge of administering the poison to the prisoner. She was condemned and executed, and confessed before execution, that she did poison her husband, and that the substance she used was the powdered root of monkshood, which is well known as a poison to the peasantry of Monaghan under the name of Blue Rocket.

It is scarcely necessary to add, that great caution must be observed in applying the general principle here inculcated. But the opposite doctrine, that no charge of poisoning can be established without the discovery of poison in the body or in the evacuations, appears to me a great error, though upheld by no mean authority. Under that doctrine few criminals would be brought to justice, were they to resort to a variety of vegetable poisons, which in certain seasons are within the reach of every one.

Section IV.—Evidence from Experiments on Animals.

Evidence from experiments on animals with articles supposed to contain poison is more equivocal than was once imagined. But it may be doubted whether some medical jurists have not overstepped the proper limits, when they hold it to constitute little or no proof at all.

Evidence from express experiments should rarely form part of a regular medical inquiry into a charge of poisoning. For in the first place, to make sure of performing an experiment well requires more experimental skill than the generality of practitioners can be expected to possess; then, as will seen in the sequel, evidence procured from this source can very rarely be more than presumptive; and lastly, if the quantity of poison in the suspected substance is great enough to affect one of the perfect animals, it may generally be recognized to a certainty by its physical or chemical properties.

For these reasons it is not likely, that, in an inquiry undertaken by a skilful toxicologist, he will put himself in the way of delivering an opinion on the force of such evidence. But it is nevertheless necessary for me to consider it in detail, because he may have to give his opinion regarding experiments made inconsiderately by others, or accidents caused by domestic animals eating the remains of substances suspected to be poisoned.

The matter subjected to trial may be either suspected food, drink, or medicine; or it may be the stuff vomited during life, or found in the stomach after death; or it may be the flesh of poisoned animals.

1. The evidence derived from the effects of suspected food, drink, or medicine is better than that drawn from the effects of the vomited matter or contents of the stomach. But an important objection has been made to both, namely, that what is poison to man is not always poison to the lower animals, and that, on the other hand, some of the lower animals are poisoned by substances not hurtful to man.

A good deal of obscurity still hangs over the relative effects of poisons on man and the lower animals. There are two species, however, whose mode of life in respect to food closely resembles our own, and which, according to innumerable experiments by Orfila, are affected by almost all poisons exactly in the same way as ourselves, namely, the cat and dog, but particularly the latter.

In general poisons act less violently on these animals; thus two drachms of opium are required to kill a middle-sized dog,[^[105]] while twenty grains have killed a man, and undoubtedly less would be sufficient. It appears that one poison, alcohol, acts more powerfully on them than on man. There are also some poisons, such as opium, which, although deleterious to them as well as to man, nevertheless produce in general different symptoms. Yet the differences alluded to are probably not greater than exist between man and man in regard to the same substances; and therefore it may be assumed, that, on the whole, the effects of poisons on man differ little from those produced on the dog and cat.

The present objection is generally and perhaps justly considered a stronger one, when it is applied to other species of animals. But it must be confessed after all, that our knowledge of the diversities in the action of poisons on different animals is exceedingly vague, and founded on inaccurate research; and there is much reason to suspect, that, if the subject is studied more deeply, the greater number of the alleged diversities will prove rather apparent than real. Both reasoning and experiment, indeed, render it probable, that some orders, even of the perfect animals, such as the Ruminantia, are much less sensible than man to many poisons, and especially to poisons of the vegetable kingdom. But so far as maybe inferred from the only accurate inquires on the subject, their effects differ in degree more than in kind. Some exceptions will without doubt be found to this statement. For example, oxalic acid, besides inflaming the stomach, causes violent convulsions in animals, but in man it for the most part excites merely excessive prostration; and opium most generally excites in man pure sopor, in animals convulsions also. Other exceptions, too, exist by reason of functional peculiarities in certain animals. Thus irritant poisons do not cause vomiting in rabbits or horses, because these animals cannot vomit; neither do they appear to cause much pain to rabbits, because rabbits have not the power of expressing pain with energy. But exceptions like these, and particularly such as are unconnected with functional peculiarities, will probably prove fewer in number, and less striking than is currently imagined. For it is, on the other hand, well ascertained, that many, indeed most of the active poisons whose effects have been examined by a connected train of experiments, produce nearly the same effects on all animals whatever from the highest to the lowest in the scale of perfection. It has been fully proved, that arsenic, copper, mercury, the mineral acids, opium, strychnia, conia, white hellebore, hydrocyanic acid, cyanogen gas, sulphuretted hydrogen, and many others, produce nearly the same effects on man, quadrupeds, birds, amphibious animals, and even on fishes and insects.[^[106]]

Accordingly there are cases, in which the evidence from experiments on animals with suspected articles of food is unequivocal. For example;—a sexton and his wife, who had got a bad name in their village in consequence of informing against the bailiff for smuggling, and who were on that account shunned by all the neighbours, accused the bailiff and his wife of having tried to poison them by mixing poison with their bread. Immediately after eating they were attacked, they said, with sickness, griping, swelling, and dizziness; and they added, that a cat was seized with convulsions after eating a part of it, had sprung away, and never returned. A large portion of the loaf was therefore sent to the Medical Inspector of the district; who reported, that it seemed exactly similar to another unsuspected loaf;—that, although he was not able to detect any poison, it might after all contain one,—vegetable poison particularly;—but that he could hardly believe it did, for he fed a dog, a cat, and a fowl several days with it, and they not only did not suffer any harm, but even appeared very fond of it.[^[107]] In this case it was clear that poisoning was out of the question. On the other hand, the effects of some poisons on man may be developed so characteristically in animals as to supply pointed evidence. Thus, in the case of Mary Bateman, an infamous fortune-teller and charm-worker, who after cheating a poor family for a series of years, at last tried to avoid detection by poisoning them, it was justly accounted good evidence, that a portion of the pudding and the honey, supposed to have been poisoned, caused violent vomiting in a cat, killed three fowls, and proved fatal to a dog in four days, under symptoms of irritation of the stomach such as were observed in the people who died.[^[108]]

It has been farther objected to experiments on animals with suspected articles of food, drink, or medicine, that it is difficult to administer poison to them in a state of concentration, and to prevent it from being discharged by vomiting. This objection, however, may be obviated by performing the experiment in the way recommended by Professor Orfila. A small opening is made into the gullet, previously detached from its surrounding connexions, the liquid part is introduced by a funnel thrust into the opening, and the solid portion previously made into little pellets is then squeezed down. Lastly, the gullet is tied under the aperture. The immediate effect of the operation is merely an appearance of languor; and no very serious symptom is observable till four or five days at soonest after the tying of the gullet. Hence if signs of poisoning commence within twenty-four hours, they are independent of the injury done by the operation.[^[109]] This process requires some adroitness to execute it well. It cannot be tried successfully but by a practised operator, who, for reasons already given, would hardly ever try experiments of the kind with suspected articles. Mention is here made of it, therefore, chiefly because it is the best mode of experimenting in those cases in which it is necessary, as will presently be seen, to determine disputed points in the physiology of poisons.

I may here shortly notice a method which has been lately proposed for detecting poisons that enter the blood, and which is founded on their effects on animals. M. Vernière suggests that advantage may be taken of the extreme sensibility of the medicinal leech to procure at least presumptive evidence, when no evidence can be procured in any other manner. He has related some experiments to prove that the leech, when placed in the blood of dogs killed by nux-vomica, is affected even when the quantity of the poison is exceedingly small.[^[110]] It is extremely doubtful whether any importance can be attached to this criterion, as every one knows that the leech is apt to suffer from a variety of obscure causes, and among the rest from some diseased states of the body.

2. In the case of the vomited matter or contents of the stomach there are other and weightier objections to experiments on animals.—In the first place, the poison which has caused death may have been either in part or wholly vomited before-hand, or absorbed, or transmitted into the intestines, or decomposed by the process of digestion. Secondly, though abounding in the matter vomited or which remains in the stomach, it may be so much diluted, as not to have any effect on an animal. And, thirdly, the animal fluids secreted during disease are believed to act occasionally as poisons.

The first two objections are so plainly conclusive as scarcely to require any illustration. It may be well, however, to mention as a pointed practical lesson, that Professor Orfila once detected a considerable quantity of arsenic in the contents of the stomach, where a prior investigation had shown that the same article produced no effect on two animals, and where the reporters from this and other circumstances declared, that in their opinion death was not owing to poison.[^[111]]

The last objection is a very important one; but there is reason for suspecting that it has been a good deal exaggerated by medical jurists.—Animal fluids are certainly poisonous when putrid. The repeated and fatal experience of anatomists, together with the precise experiments of M. Gaspard and M. Magendie,[^[112]] leave no doubt that putrid animal fluids, when introduced into an external wound, cause spreading inflammation of the cellular tissue; and although Magendie says he has found such fluids harmless when introduced into the stomach of dogs,[^[113]] it is probable, from their effects on man, that they will act as irritants on animals not habituated to their use. I believe, too, that independently of putrefaction, vomited matter or the contents of the stomach may be apt to make dogs vomit on account of their nauseous taste; and perhaps we may infer, that they will also cause some of the other symptoms of poisoning with the irritants, particularly if not vomited soon after being administered.—As to the influence of disease in rendering the contents of the stomach deleterious, it is to be observed that the effects just mentioned are probably owing to the influence of disease on the secretions, but that beyond this we know very little of the subject. In authors I have hitherto found only one fact to prove that disease can render the contents of the stomach decidedly poisonous; and on the negative side of the question there exists no facts at all. Morgagni describes the case of a child who died of tertian ague, amidst convulsions, and in whose stomach a greenish bile was found, which proved so deleterious, that a little of it given with bread to a cock caused convulsions and death in a few minutes, and a scalpel stained with it, when thrust into the flesh of two pigeons, killed them in the same manner.[^[114]] It is not easy to say what to think of this experiment; which, if admitted to the full extent of the conclusions deducible from it, would lead to the admission, that disease may impart to the secretions the properties of the most active narcotics. Farther researches are certainly required before this admission can be made unreservedly.

On the whole, it appears that in the present state of our knowledge, experiments or accidental observations on the effects of the contents of the stomach, or of vomited matter, on animals are equivocal in their import. At the same time it may be observed, as with regard to articles of food, drink, or medicine, that the effects of some poisons on man may be developed so characteristically on animals by the contents of the stomach, as to supply very pointed evidence indeed. Of the force of this statement the following example is a striking illustration. In the case of a girl, who was proved to have died of accidental poisoning with laudanum, the inspector evaporated the contents of the stomach to dryness, made an alcoholic extract from the residue, and giving this to several dogs, chickens, and frogs, found that they were all made lethargic by it, some of them oftener than once, and that a few died comatose.[^[115]] Facts such as these, agreeing so pointedly with the known effects of the poison suspected, appear to me to yield evidence almost unimpeachable.

3. The effects of the flesh of poisoned animals, eaten by other animals, constitute the least conclusive of all the varieties of the present branch of evidence. For the flesh of animals that have died of poisoning is not always deleterious; while on the other hand flesh is sometimes rendered so by natural causes, as will be seen in the Chapter on Diseased and Decayed Animal Matter.

This subject stands much in need of careful and methodic investigation. And it is of more practical importance than might be imagined at first sight. For the question has actually occurred in a legal inquiry in this country,—Whether poisoning in the human subject may be caused by the flesh of a poisoned animal?

In regard to some poisons it is well established, that animals killed by them may be eaten with impunity, such as game killed with the wourali poison, or fish by cocculis-indicus. This seems the general rule. But it is not clear that all poisons are similarly circumstanced.

The only systematic researches hitherto undertaken on this question are some recently made at Lucca by Professor Gianelli; of which however I have only seen an abstract. He found that the blood, urine, and lungs of animals poisoned with arsenic acted as a poison on small birds, such as sparrows, whether the parts were taken from the body while the animal was alive, or after death; but that alcohol, cherry-laurel water, corrosive sublimate, sulphate of copper, tartar-emetic, acetate of lead, nitrate of silver, trisnitrate of bismuth, chloride of tin, sulphate of zinc, laudanum, acetate of morphia, strychnia, and cantharides, had no such effect.[^[116]] Orfila has since shown some reason for doubting the conclusiveness of Gianelli’s investigations; and on repeating them, obtained such results as render it doubtful whether any reliance can be put upon experiments made upon small birds.[^[117]] Guérard however has ascertained, that dogs, fed on the flesh and entrails of sheep which had taken arsenic, were attacked with vomiting and purging, became reduced in flesh, and at length would not eat what was put before them; but none of them perished, or seem to have been seriously ill. Arsenic was detected in their urine.[^[118]]

The importance of the inquiry, which the preceding experiments are intended to elucidate, will appear from the following singular case, for the particulars of which I am indebted to the kindness of Mr. Jamieson of Aberdeen, who was employed by the authorities to investigate it. An elderly woman, who kept fowls which occasionally trespassed on a neighbour’s fields, one morning observed four of them very sickly; and in the course of the day they became so ill that she killed them. She cleaned and prepared two of them for cooking, buried another, and gave away the fourth to a beggar, who was afterwards lost sight of. Next day soup made with the half of one of the fowls was given to a little girl, who suffered severely from sickness and vomiting, and also to a cat, which was similarly affected for the whole evening. On the day afterwards the woman herself and a female lodger, took broth made with what remained of the fowls, and also ate the gizzards; but the remainder was thrown with the offal upon the dunghill. In the course of five or six hours both women were attacked with severe illness. One had sickness, vomiting and great coldness; but after encouraging the vomiting with hot water and then taking some spirits, she got better in the night-time, and next morning was pretty well. The other, who was the owner of the fowls, was seized somewhat later than her friend with great thirst and shivering, and next day with pains in the stomach, severe sickness, and fruitless efforts to vomit. On the sixth day, when a medical man first saw her, she had great pain throughout the abdomen, much thirst, difficult breathing, a red, dry tongue, and a very frequent, small pulse. Next day the pain and difficult breathing became worse; and in the evening, after an attack of sneezing, she became gradually insensible and motionless, in which state she remained till the tenth day, when she expired. The stomach and intestines did not present any distinct morbid appearance; but the vessels of the brain were turgid, there were about two ounces of serosity in the lateral ventricles, both corpora striata were softened anteriorly, and a clot of blood as big as an almond was contained in the right anterior lobe of the brain.—A judicial investigation being ordered, it was ascertained that the fowl which the woman buried as well as the remains of the other fowls which were thrown upon the dunghill, had been carried off. But on searching the dunghill more carefully afterwards, the contents of one of the crops, which had been taken out and examined by the lodger, were discovered in the rubbish; and in the mass Mr. Jamieson detected a considerable quantity of arsenic.

This incident happened in 1836. More lately the same gentleman met with another extraordinary attempt of the same kind. A farmer, about to be married, gave directions for killing in the evening some fowls which were to be sent to the house of his bride where the ceremony was to take place. The killing of them however was accidentally delayed; and next morning, on the hen-house door being opened, the fowls ran furiously to the well, drank water incessantly, and died in an hour. On examining the bodies, Mr. Jamieson found arsenic in large quantity in their crops and gizzards.

On each of these occasions a particular individual came under suspicion; but the evidence against them was too slight to justify the authorities in bringing a formal charge; and consequently the proceedings did not go farther. In the former instance the evidence in favour of the flesh of poisoned animals being sometimes poisonous is strong; and the history of the woman’s case, although death seems to have been caused directly by apoplexy, renders it probable that even dangerous results might accrue.

The preceding remarks will enable the medical witness to know under what circumstances accidental observations or intentional experiments on animals furnish satisfactory proof.

Before quitting the subject, however, I have to add, that there is another purpose, besides procuring direct evidence, to which experiments with animals may be applied with great propriety;—namely, the settling disputed questions regarding the physiological and pathological properties of a particular poison. The science of toxicology is not yet by any means so perfect, but in particular cases topics may arise, which have not hitherto been investigated, and which it may be necessary to determine by experiment. Experiments on animals instituted for such purposes by a skilful toxicologist are not liable to any important objection. On the trial of Charles Angus at Liverpool in 1808, for procuring abortion and murder by poison, a trial of great interest, which will be referred to more particularly afterwards, it appeared from the evidence of the crown witnesses, that the poison suspected, corrosive sublimate, could not be discovered in the stomach by certain methods of analysis; and that, although corrosive sublimate is a powerful irritant, the villous coat of the stomach was not inflamed. But then it was proved by experiments made by one of their number, Dr. Bostock, that animals might be killed with corrosive sublimate without the stomach being inflamed, and without the poison being discoverable after death by the tests he used in the case.[^[119]] An attempt was made on the side of the prisoner to throw out this line of evidence as incompetent, on the ground of the discrepant effects of poisons on man and on the lower animals. But it was admitted by the judge, on the plea that it was only to illustrate a general physiological fact, and not to infer proof of poisoning. The importance of experiments on animals to settle incidental physiological questions has lately been again acknowledged in a very pointed manner in an English court of law: for a set of experiments, to settle the question of the rapidity with which hydrocyanic acid acts, was instituted before the trial by the medical witnesses, at the request of the judge who was to try the case.[^[120]]

Section V.—Of the Moral Evidence.

It is not my object to treat under this head of the moral evidence generally, which is required to establish a charge of poisoning. But as it is well known that in criminal trials medical witnesses have for the most part nothing to do with the moral proof, while at the same time in cases of poisoning the medical and moral circumstances are always intimately interwoven and apt to be confounded together, it is necessary for me to specify those particulars of the moral evidence, which either require some medical skill to appreciate them, or fall naturally under the cognizance of the physician in his quality of practitioner. I shall enter into greater details under this section than may perhaps appear to the medical reader necessary, chiefly that I may redeem the pledge given in the introduction to the lawyer and general reader, and endeavour to show how powerful an instrument a medico-legal investigation may become in skilful hands, for throwing light on almost every branch of the evidence.

The moral or general proof in charges of poisoning is almost always circumstantial only. The circumstances of which it usually consists relate, 1. To suspicious conduct on the part of the prisoner before the event, such as dabbling with poisons when he has nothing to do with them in the way of his profession, or conversing about them, or otherwise showing a knowledge of their properties not usual in his sphere of life:—2. To the purchase or possession of poison recently before the date of the alleged crime, and the procuring it in a secret manner, or under false pretences, such as for poisoning rats when there are none on his premises, or for purposes to which it is never applied:—3. To the administration of poison either in food, drink, medicine, or otherwise:—4. To the intent of the prisoner, such as the impossibility of his having administered the poison ignorantly, or by accident, or for beneficial purposes, alleged or not alleged:—5. To the fact of other members of the family besides the deceased having been similarly and simultaneously affected:—6. To suspicious conduct on the part of the prisoner during the illness of the person poisoned,—such as directly or indirectly preventing medical advice being obtained, or the relations of the dying man being sent for, or showing an over-anxiety not to leave him alone with any other person, or attempting to remove or destroy articles of food or drink, or vomiting matter which may have contained the poison, or expressing a foreknowledge of the probability of speedy death:—7. To suspicious conduct after the person’s death, such as hastening the funeral, preventing or impeding the inspection of the body, giving a false account of the previous illness, showing an acquaintance with the real or supposed effects of poison on the dead body:—8. To the personal circumstances and state of mind of the deceased, his death-bed declaration, and other particulars, especially such as tend to prove the impossibility or improbability of suicide:—9. To the existence of a motive or inducement on the part of the prisoner, such as his having a personal quarrel with the deceased, or a hatred of him,—his succeeding to property by his death, or being relieved of a burthen by it,—his knowing that the deceased was with child by him.

Upon many of the particulars now enumerated, important evidence may be derived from the medical part of the investigation; and not unfrequently such evidence can be collected or appreciated only by means of a medico-legal inquiry.

1 and 2. On the first two articles, suspicious conduct or conversation on the part of the prisoner before the crime, and the possession or purchase of poison by him, little or nothing need be said. The medical witness may of course be asked whether the conduct or conversation proved betokens an unusual acquaintance with poisons and their effects. And his opinion may be referred to regarding the nature of suspected articles found in the prisoner’s possession. As to the purchase of arsenic under the false pretence of poisoning rats, it may be observed, that a great deal more stress is usually laid on such evidence than it seems to deserve; for there are few houses, in the country particularly, which are not more or less infected by them. On the other hand, too little weight is attached to the circumstance of the purchaser not having warned his household of poison being laid. Such conduct ought in my opinion to be accounted extremely suspicious; for so far as I have remarked, the fear with which unprofessional persons regard the common poisons is such, that I can hardly believe any master of a house would actually lay poison without warning the servants and other inmates of his having done so.

3. The next article, which relates to the proof of the administration of poison, will require some details.

Direct proof of the administration of poison by the actual giver is very rarely attainable, that part of the transaction being for the most part easily concealed. The proof of this point is justly accounted, however, a very important part of the evidence; nay, on some recent trials in this country the prosecution has failed apparently for want of such evidence, although the case was complete in every other particular. It is generally constituted by a chain of circumstances, and these are often strictly medical, as will now be shown by a few examples.

In the first place, pointed evidence as to the individual who gave the poison may be derived from the chemical investigation,—for example, from the comparative results of the analysis of the poisoned dish, and of the articles of which it consisted. I am indebted to my colleague, Dr. Alison, for the following excellent illustration from the case of William Muir, who was condemned at Glasgow in 1812 for poisoning his wife. In the course of the day on which she took ill she was visited by a farmer of the neighbourhood, who had studied physic a little in his youth. He learned from her that she had breakfasted on porridge a short time before she felt herself ill, and that she suspected the porridge to have been poisoned. He immediately procured the wooden bowl or cap in which the cottagers of Scotland keep the portion of meal used each time for making the porridge; and finding in it some meal, with shining particles interspersed, he wrapped a sample in paper, and took the proper measures for preserving its identity. He then secured also a sample from the family store in a barrel. The two particles were produced by him on the trial; and from experiments made in court the late Dr. Cleghorn was enabled to declare, that the meal from the bowl contained arsenic, and that the meal from the barrel did not. These facts, besides proving that the woman had next to a certainty taken arsenic in the porridge, likewise, in conjunction with other slight moral circumstances, established that the poison had been mixed with the meal in the house, and on the morning when the deceased took ill, before any stranger entered the house. The procedure of this farmer was precisely that which ought to be followed by the medical practitioner in a similar conjuncture.

An instance of an opposite description related by M. Barruel also deserves notice, as showing how evidence of this kind may afford, in otherwise suspicious circumstances, a strong presumption of accidental poisoning. Sixteen people near Bressières in France having been severely affected with vomiting and colic immediately after dinner, the bread, which was suspected, was examined by Barruel, and found to contain a little arsenic. The flour of which the bread was made had been taken from a large store of it, which, on being examined, was also found to be similarly impregnated. As it was extremely improbable that any one either could or would poison so large a mass of flour, to attain any malicious object, it was inferred that the arsenic had been mixed with it accidentally, and that the accident might have arisen from grain having been taken by mistake to the flour-mill to be ground, which had been intended originally for seed, and sprinkled with arsenic to destroy insects.[^[121]]

It may be worth while observing, in the present place, that in the instance of poisoned wine very important evidence may be obtained by examining whether the wine with which the cork is impregnated contains any traces of the poison. This method of investigation occurred to me in a very singular case of poisoning with arsenic in champagne, which happened in a baronet’s family in Scotland. In this instance, however, such analysis was proved to be unnecessary; for the gentleman himself brought the bottle from his cellar, broke the wires and drew the cork, immediately before the wine was drunk.[^[122]]

All evidence of the like nature, though it is at present often procured from other sources, should, for obvious reasons, be invariably collected, if possible, with the aid of a medical person. If again a medical man is called to a patient evidently affected with suspicious symptoms, and finds himself obliged to declare such to be his opinion, his thoughts, as soon as he has given directions for the treatment, should be turned towards that part of the evidence, for the securing of which he is naturally looked to as the person best qualified by previous education and his opportunities at the moment. With this view, therefore, having ascertained in what articles it is possible for poison to have been administered, he should at once endeavour to secure the remains of the particular portion partaken of by his patient, as well of the general dish, if it is an article of food, and of the ingredients of which the dish was ostensibly made, not forgetting the salt with which it was seasoned. A case occurred some years ago in the north of Scotland, in which arsenic was administered in porridge by mixing it with the salt.

It is of great consequence, before proceeding to analyze such articles, for example suspected dishes,—to be particular in investigating every thing connected with the cooking, serving, and eating of them. By doing so, not only will the chemical analysis be facilitated, but likewise facts in it will be accounted for, which might otherwise prove embarrassing, and even lead to the drawing of false conclusions from the result of the analysis. This statement is very well exemplified by the following incident which occurred to myself. In 1827 a family in Portobello were poisoned by the maid-servant; and it was believed, that, for the sake of a trick, she had, while carrying to the oven the beef subsequently used at dinner, maliciously mixed with it tartar-emetic or some other poison. One-half of the beef having been preserved, and two persons of the family having been very severely affected, Dr. Turner and I, to whom the case was remitted, made little doubt that we should discover the poison by chemical analysis: but we did not. Being subsequently employed by the sheriff to inquire into the particulars, I found that the poison had been mixed with the gravy, which had been consumed almost to the last drop,—that the gravy had been poured over the beef,—that the upper half of the beef had been eaten,—and that the remainder which we analysed had been transferred upon a different plate from that on which it was served for dinner. These particulars accounted sufficiently for the poison not having been discovered.

Another mode in which the chemical part of the inquiry may contribute to discover the individual who administered the poison is by a comparative examination of the persons of the deceased and the accused. The following very pointed illustration has been published by MM. Ollivier and Chevallier of Paris.—A woman who lived on bad terms with her husband was found dead on a roadside the morning after having been seen drunk in his company in the neighbourhood. The mouth, throat, and gullet were proved by a careful analysis to be corroded with nitric acid, the stains and traces of which were also found on various parts of her dress, and on the hair, neck, and arms, but not on her hands, and not lower down the alimentary canal than the upper fourth of the gullet. Ollivier, suspecting from these appearances, that she had not taken the acid voluntarily, requested to see the husband; whereupon there were found on his coat, trousers, and hands, a great number of stains, which, like those on the deceased, were proved by chemical analysis to have been produced by nitric acid. Here it was scarcely possible to avoid inferring, that the man got these stains while endeavouring to force his intoxicated wife to take the poison Marks of nail scratches were also observed round the mouth and on the throat; whence it was reasonably inferred, that, having failed in his original plan, he had suffocated her with his hands.[^[123]]

While these illustrations are given of the conclusiveness of the chemical evidence in fixing the administration of poison on a particular individual, it is essential likewise to observe that the same kind of evidence may be at times equally conclusive of the innocence of a person unjustly suspected. This obvious and important application of a chemical inquiry is forcibly suggested by the following particulars of an incident related by M. Chevallier:—An individual was accused by a woman of having tried to poison her; and she represented that he had put the poison into her soup, while it stood from one day to another in an iron pot. On making a careful analysis of some of the soup which remained, Chevallier found it so strongly impregnated with copper, that, supposing the sulphate was the salt mixed with the soup, ten ounces must have contained twenty-two grains. It then occurred to him, that it was important to examine the iron pot, in which the poisoned soup was represented to have been kept; for the probability was that a large quantity of the copper, if any salt of that metal had really been contained in the soup, would have been thrown down by the superior affinity of the iron, and consequently that a coppery lining would be found on the inside. He was led, however, to anticipate that no copper would be found there, because there was no iron dissolved in the soup, as would have been the case if copper had been precipitated from it by the iron of the pot. And accordingly he not only found no copper lining the inside of the pot; but likewise, on following the process described by the accuser as the one pursued in cooking the soup and in subsequently poisoning it, he satisfied himself by express trial that there was nothing in the circumstances of the case which could have prevented the iron from exerting its usual action on the salts of copper. These conclusions, coupled with certain facts of general evidence, proved substantially that the suspected person had nothing to do with the crime charged against him; and he was therefore discharged.[^[124]] A case somewhat similar will be related under the head of Imputed Poisoning.

In the second place, evidence as to the person who administered the poison may be procured by considering the commencement of the symptoms, in relation to the time at which particular articles have been given in a suspicious manner by a particular individual. The import of facts of this nature can be properly appreciated only by the medical witness; for he alone can be acknowledged as conversant with the symptoms which poisons produce, the intervals within which they begin to operate, and the circumstances in which their operation may be put off or accelerated.

Few cases will occur in which it is not possible to procure evidence of the kind, when diligently sought for. It is often too very decisive in its operation on judicial proceedings. In the case of Margaret Wishart tried at the Perth Spring Circuit in 1827 for poisoning her blind sister, a man who lodged with the prisoner and cohabited both with her and with the deceased, appeared at first from general circumstances to be implicated in the crime. He had left the house, however, on the morning of the day before that on the evening of which the deceased took ill; and he did not return till after her death. Now her illness commenced suddenly and violently; and arsenic was the poison which caused it.[^[125]] It was quite clear, therefore, that the poison could not have been administered, at least in a dangerous dose, so early as the day before she was taken ill; and such I stated to be my opinion, on a reference from the Lord Advocate. The evidence being also otherwise insufficient, the man was set at liberty. In the case of Mrs. Smith tried here in February of the same year, this branch of the evidence was made the subject of question under more doubtful circumstances. The deceased certainly died of poisoning with arsenic, and the prisoner was strongly suspected of being the poisoner for many reasons, and among others because, on the evening before the morning on which the deceased took ill, the prisoner gave her in a suspicious manner a white-coloured draught. Here the possibility of the draught having been the cause of the symptoms must be admitted. But as they did not appear for eight hours after the draught was taken, I stated in my evidence that it was improbable the dose, if it contained arsenic at all, contained a quantity sufficient to cause the violent symptoms and death which followed.[^[126]]

The correspondence in point of time between the appearance of symptoms of poisoning, and the administration of suspicious articles by an individual, constitutes still more decisive proof in a set of cases, in which it is of great value, as the chemical evidence is generally defective,—namely, where poisoning is attempted with repeated moderate doses. If the several renewals or exacerbations of illness correspond with the periods when suspicious articles have been given by the same individual, the circumstantial evidence of the administration may be even tantamount to direct proof. Thus, on the trial of Miss Blandy for the murder of her father, it was proved, that Mr. Blandy on several occasions, after the prisoner received certain suspicious powders from her lover, was taken ill with vomiting and purging; and that on two occasions recently before his death, when he got from his daughter a bowl of gruel which contained a gritty sediment, he was attacked after a very short interval with pricking and heat in the throat, mouth, stomach, and bowels,—with sickness, vomiting, gripes, and bloody diarrhœa.[^[127]] Here the proof of administration by the prisoner was complete.

These examples will show how the evidence of a particular person’s criminality may be affected by the relation subsisting in point of time between the commencement of the symptoms and the suspicious administration of particular articles. But farther, the special period at which the symptoms begin may even at times supply strong evidence of his instrumentality, although there may be no direct proof from general evidence of his having been concerned in administering anything whatever in a suspicious manner. This statement is well exemplified by the case of Mrs. Humphreys, who was convicted at the Aberdeen Autumn Circuit in 1830 for poisoning her husband, by pouring sulphuric acid down his throat while he was asleep. It was clearly proved, as will be seen under the head of sulphuric acid, that the deceased died of this poison; and the administration was brought home to the prisoner in the following singular manner. The only inmates of the house were the deceased, the prisoner, and a maid-servant. The deceased got a little intoxicated one evening at a drinking party in his own house; and after his friends all left the house, and the street-door was barred inside, he went to bed in perfect health, and soon fell fast asleep. But he had slept scarcely twenty minutes, when he suddenly awoke with violent burning in his throat and stomach; and he expired in great agony towards the close of the second day. Now sulphuric acid, when it occasions the violent symptoms observed in this instance, invariably excites them in a few seconds, or in the very act of swallowing. It was, therefore, impossible that the man could have received the poison at the time he was drinking with his friends; and as he knew he had not taken any thing else afterwards, and it was fully proved that he had been asleep before his illness suddenly began,—it followed that the acid must have been administered after he fell asleep, the accomplishment of which was rendered easy by a practice he had of sleeping on his back with his mouth wide open. But, after he gave the alarm, the door was found barred as when he went to bed. Consequently no one could have administered the poison except his wife or servant; and it was satisfactorily proved, that no suspicion could attach to the latter. Such was one of the principal train of circumstances, which, as it were by a process of elimination, led to the inference that the wife was undoubtedly the person who administered the poison. Other circumstances of a similar tendency were also derived from the medical evidence; but these it is unnecessary to detail at present. I have related the particulars of the whole case fully elsewhere.[^[128]] The prisoner strenuously denied her guilt after being sentenced, but confessed before her execution.

4. The next article in the moral evidence relates to the intent of the person who is proved to have administered poison. When the administration is proved, little evidence is in general required to establish the intent. It is sufficient that the giver knew the substance administered was of a deadly nature; and in regard to any of the common poisons this knowledge is sufficiently constituted by his simply knowing its name.

In some cases, however, the exact nature of the poison is not established with certainty; and then something else may be required to prove the prisoner’s knowledge, and through that knowledge his intent. In the case of Charles Munn, formerly alluded to [p. [50]], arsenic was the poison presumed to have been taken by the deceased. But the purchase or possession of it by the prisoner was not for some time satisfactorily established; neither was there any chemical evidence, the deceased having lived forty days and upwards after taking the poison. It was proved, however, that whatever it was which had been administered, the prisoner knew very well that what he gave was deleterious; because he persuaded the deceased, who was pregnant by him, to take it by assigning to it properties which no drug either possesses, or is so much as thought by the vulgar to possess. On one occasion he persuaded her that it would show whether she was with child, and on another that it would prevent people from knowing she was with child. In such cases, then, good evidence may be derived from the arguments used by the giver to persuade his victim to take the poison; and sometimes, as in the instance now mentioned, it will lie with the medical witness to inform the court whether or not the reasons assigned are false.

Sometimes it has been pleaded by the prisoner that he gave the poison by mistake. In all such cases, if he descends to particulars, which he cannot help doing, there is every likelihood that the falsehood of the defence will be made evident by the particulars of the story not agreeing with other particulars of the moral or medical evidence. At present it is only necessary to allude to inconsistencies in his story with the medical facts. No general rules can be laid down on the method of investigating a case with a view to evidence of this kind: I must be satisfied with an illustration from an actual occurrence. On the trial of Mr. Hodgson, a surgeon, at the Durham Autumn Assizes in 1824, for attempting to poison his wife, it was clearly proved, that pills containing corrosive sublimate, and compounded by the prisoner, were given by him to her in place of pills of calomel and opium, which had been ordered by her physician. But it was pleaded by him, that, being at the time intoxicated, he had mistaken, for the shop-bottle which contained opium, the corrosive-sublimate bottle which stood next it. This was certainly an improbable error, considering the opium was in powder, and the sublimate in crystals. But it was not the only one which he alleged he had committed. Not long after his wife took ill, the physician sent the prisoner to the shop to prepare for her a laudanum draught, with water for the menstruum. When the prisoner returned with it, the physician, in consequence of observing it to be muddy, was led to taste it, before he gave it to the sick lady: and finding it had the taste of corrosive sublimate, he preserved it, analyzed it, and discovered that it did contain that poison. The prisoner stated in defence, that he had a second time committed a mistake, and instead of water had accidentally used for the menstruum a corrosive-sublimate injection, which he had previously prepared for a sailor. This was proved to have been impossible; for the injection contained only five grains to the ounce, while the draught, which did not exceed one ounce, contained fourteen grains.[^[129]]

I believe it must be allowed, that, as the medical inquiries preparatory to trial are commonly conducted without the inspector being made acquainted with the moral circumstances in detail, it is rarely possible for him to foresee what points should be attended to, with the view of illustrating the intent. But the case now related will show that it is impossible for him to render his inquiries too minute or comprehensive; and more particularly, it shows the propriety of ascertaining, whenever it is possible, not only the nature but likewise the quantity of the poison.

5. The next article among the moral circumstances,—the simultaneous illness of other members of the family besides the person chiefly affected,—depends for its conclusiveness almost entirely upon the researches and opinion of the medical witnesses.

The fact, that several persons, who partook of the same dish or other article, have been seized about the same time with the same symptoms, will furnish very strong evidence of general poisoning. A few diseases, such as those which arise from infection or from atmospheric miasmata, may affect several persons of a family about the same time; and hysteria, and epilepsy, have been communicated to several people in rapid succession.[^[130]] But I am not aware, that, among the diseases which resemble well marked cases of poisoning either with irritants or with narcotics, any one ever originates in such a way as to render it possible for several persons in a family to be attacked simultaneously, except through the merest and therefore most improbable accident. Cholera perhaps is an exception. But when cholera attacks at one time several people living together, it arises from bad food, and is properly a variety of poisoning. In such cases, too, the fallacy may in general be easily got the better of, by finding that the store or stock, from which the various articles composing the injurious meal have been taken was of wholesome quality.

Hence it may be laid down as a general rule, that, perhaps if two, but certainly if three or more persons, after taking a suspected article of food or drink, are each affected with symptoms, furnishing of themselves presumptive evidence of poisoning, and have been seized nearly about the same time, and within the interval after eating within which poisons usually begin to act,—the proof of poisoning is decisive. Several late cases might, in my opinion, have been decided by this rule. Thus it might have decided the important case of George Thom tried at Aberdeen in 1821 for poisoning the Mitchells, and likewise that of Eliza Fenning, about whose condemnation some clamour was made in London in 1815. In both instances, as will be mentioned under the head of arsenic, the symptoms were developed so characteristically, that from them alone poisoning with arsenic might have been inferred almost to a certainty. But even if the symptoms had been somewhat less characteristic, all doubt of general poisoning was set aside by the fact, that four persons in the former case, and five in the latter, were similarly and simultaneously affected, and all of them at an interval after eating, which corresponded with the interval within which arsenic usually begins to act.

Sometimes it happens, that while one or more of a party at a certain meal suffer, others escape. Such an occurrence must not be hastily assumed as inconsistent with poison having been administered at that meal. For the guilty person may have slipped the poison into the portion taken by the individual or individuals affected.

If it be proved that all who ate of a particular dish have suffered, and all who did not have escaped, the kind of moral evidence now under review becomes strongest of all. It is well for the medical jurist to remember also, that such evidence is very useful in directing him where chiefly he should look for poison.

At other times it happens that the several people affected, suffer in proportion to the quantity taken by each of a particular dish. Too much importance ought not to be attached to the absence of that relation; for it has been already mentioned that habit, idiosyncrasy, and the state of fulness of the stomach at the time, will modify materially the action of poisons. But when present, it will often form strong evidence.—A good illustration of what is now said may be found in the case of Thomas Lenargan, tried in Ireland for the murder of his master, Mr. O’Flaherty. He had for some time carried on an amour with O’Flaherty’s wife; and afterwards, to get rid of the troublesome surveillance of the husband, contrived to despatch him by poison. The crime was not suspected for two years. Among the facts brought out on the trial the most pointed were, that O’Flaherty’s daughter and two servants were affected at the same time with the very same symptoms as himself; that they had partaken of the same dish with him; that the severity of their several complaints was in proportion to the quantity each had taken; and that others of the family, who did not eat it, were not affected.[^[131]]

Another remarkable instance of this kind has been recorded by Morgagni. A clergyman, while travelling in company with another gentleman and two ladies, was setting out one afternoon to resume his journey after dining at an inn, when he was suddenly taken ill with violent pain in the stomach and bowels, and soon after with vomiting and purging. One of the ladies was similarly affected, but in a less degree; and likewise the other gentleman, though in a degree still less: but the other lady did not suffer at all. Morgagni found, that this lady was the only one of the party who had not tasted a dish of soup at the commencement of dinner. But he was puzzled on finding that the gentleman who suffered least had taken the largest share of the soup, while the clergyman had taken less than either of the two that were seized along with him. He then remembered, however, that in the district where the accident happened, it was the custom to use scraped cheese with the soup in question; and on inquiry he was informed that they had each added to the soup a quantity of cheese proportioned to the severity of their illness. Here, therefore, Morgagni was led to suspect the presence of poison; and accordingly, after the whole party had fortunately recovered, the innkeeper acknowledged, that in the hurry of preparation, he had served up to his guests cheese seasoned with arsenic to poison rats.[^[132]] This interesting anecdote shows, that the truth in such cases is not always to be discovered without minute inquiry and considerable adroitness. In the case of poisoning with arsenic in wine formerly alluded to,—where all the individuals at table, to the amount of six, were severely affected during dinner,—the soup was the article suspected, because all had partaken of it; and, accordingly, the soup and vomited matter were sent to me for analysis. On detecting a trace of arsenic in the vomited matter, but none in the soup, I suggested that some other article might have been used in common by the party, and mentioned the wine as a probable article of the kind. It turned out that all had drunk a single glass of champagne from a particular bottle; and in the wine remaining in this bottle arsenic was found in the proportion of half a grain per ounce.[^[133]]

Cases of this nature are so instructive that no apology need be made for mentioning one example more which lately came under my own notice. In the case of Mary Anne Alcorn, convicted here in the summer of 1827, of having administered poison to her master and mistress (a case already referred to for another purpose, p. [75]), it was proved that a white powder was introduced in a suspicious manner into the gravy of baked beef, which gravy was subsequently poured over the beef. Now the master of the family dined heartily on beef, potatoes and rice-pudding, and mixed the greater part of the beef gravy with his pudding; the mistress ate moderately of the first slices of the beef, took very little gravy, even to the beef, and none at all to the pudding; a little girl, their niece, dined on pudding alone, without gravy; and the prisoner dined after the family on the beef and potatoes. Accordingly the master suffered so severely as for two or three days to be in danger of his life, the mistress was also severely, but by no means so violently affected, the little girl did not suffer at all, and the servant had merely slight pain and sickness at stomach. The evidence thus procured was exceedingly strong, more particularly when coupled with the fact, that the beef used was half of a piece, the other half of which had been used by the family two days before, without any ill consequences.

6. The next article of the moral evidence relates to suspicious conduct on the part of the prisoner during the illness of the person poisoned. Under this head it is necessary merely to state what I conceive to be, with reference to the present branch of the proof, the duty of the medical practitioner who happens to attend a case of poisoning.

In such a conjuncture he is undoubtedly placed in a situation of some delicacy. But on considering the matter attentively, good reasons will appear why he should adopt the course, which, I believe, our courts of justice will expect of him, and keep some watch over the actions of any individual who is suspected of having committed the crime. On the one hand, no one else is by education and opportunities so capable of remarking the motions of the different members of the family dispassionately, without officiousness, and without being observed. And on the other hand, it is undoubtedly a part of his private duty as practitioner, to protect his patient against any farther criminal attempts, as well as part of his public duty to prevent the vomited matter and other subjects of analysis from being secretly put away or destroyed. No one can be so occupied without many accessary particulars coming under his notice. And certain it is, that on several trials the practitioner has contributed, with great credit to himself, a considerable part of the pure moral proof. For an example of discreet and able conduct under these trying circumstances, the reader will do well to refer to that of Dr. Addington, the chief crown witness, both as to medical and moral facts, in the case of Miss Blandy.[^[134]] It is almost unnecessary to add, that in acting as now recommended, the physician must conduct himself with circumspection, in order to avoid giving unnecessary offence, or alarming the guilty person.

7, and 9. On the seventh article, which respects the conduct of the prisoner after the death of the deceased, and on the ninth, which relates to the existence of a motive or inducement to the crime, nothing need be said here. But on the

8th article of the moral evidence,—comprehending the death-bed declaration of the deceased, his state of mind, his personal circumstances and other points which prove the possibility or impossibility of voluntary poisoning—a few remarks are required, because an important and little understood part of the practitioner’s duty is connected with this branch of the proof.

The question as to the possibility of the poisoning being voluntary is one upon which the medical attendant will be expected to throw some light, and into which he will also naturally inquire for his own satisfaction. In doing so his attention will be turned to circumstances purely moral, which may not only decide that question, but may also criminate a particular individual. His inquiries must therefore be conducted with discretion, and for obvious reasons should be confined as much as possible to the patient himself. They are to be conducted not so much by putting questions, as by leading him to disburden his mind of his own accord; and it is well to be aware, that there is no one of whom a patient is so ready to make a confident on such an occasion as his medical attendant.

If disclosures of consequence are made, and the attendant should feel it his duty to look forward to the future judicial proceedings and to the probability of his appearing as a witness, he ought to remember the general rule is, that his account of what the patient told him is not evidence in the eye of the law, unless it was told under the consciousness of the approach of death. Of late, however, the rigour of this principle in law has been occasionally departed from in Scottish practice; and in regard to medical facts ascertained in the way here mentioned, many strong reasons might be assigned for such relaxation. Evidence of the kind is technically called the death-bed declaration of the deceased, and is justly accounted very important.

Here it is right to take notice of a part of the death-bed evidence, although it does not properly belong to the question of suicide, because it should always be collected if possible by the medical attendant, and with much greater care than is generally bestowed on it even by him—I mean the history of the symptoms previously to his being called in. On this part of the history, including particularly the time and manner in which the illness began, medical conclusions of extreme consequence are often subsequently founded: On a single fact or two may depend the fate of the prisoner. It is not enough, therefore, in my opinion, that such evidence formed a part of the death-bed declaration. If a fact derived at second hand from the deceased, and stated too by him from memory, is a material element of any of the medical opinions on the trial, it is of much importance that the information be procured by a medical man; and that the person who procured it, whether professional or not, was aware at the time of the probability of its becoming important. Such evidence, although not collected with these precautions, is admissible; but I have so often had occasion to witness the carelessness with which the previous history of cases is inquired into both in medical and medico-legal practice, that I do not see how it is possible to put trust in evidence of the kind, unless it bear marks of having been collected with care, and under an impression of its probable consequence. These statements are well illustrated by the following example:—On the trial of Mrs. Smith for poisoning her maid-servant with arsenic, it was proved that some drug was administered by the prisoner in a suspicious manner on a Tuesday evening. Now it appeared at the trial improbable that this drug contained a fatal dose of arsenic, because to her fellow-servants, of whom one slept with her, and others frequently visited her, the deceased did not appear to be ill at all for eight hours after, or seriously ill for nearly a day. On the contrary, however, a surgeon, who was called to see her on the following Saturday, a few hours before her death, deposed that, according to information communicated by herself, she had been ill with sickness, vomiting, purging, and pain in the stomach and bowels since the Tuesday evening. This evidence, if it could have been relied on, would have altered materially the features of the case, as it would have gone far to supply what all the medical witnesses considered defective, namely, proof of the administration. But at the time the surgeon made his inquiries, he did not even suspect that the girl laboured under the effects of poison. Neither he therefore nor his patient could have been impressed with that conviction of the importance of the information communicated, which was necessary to insure its accuracy, particularly as it related to a matter usually of so little consequence in ordinary medical practice as the precise date of the commencement of an illness; and it would consequently have been rash to adopt it in face of more direct and contrary evidence. Any one who examines the details of this trial as I have reported them, will at once see how much the case turned on the point now alluded to.[^[135]]

CHAPTER III.
OF IMAGINARY PRETENDED, AND IMPUTED POISONING.

The present seems the most convenient place for noticing the general mode of procedure by which the medical jurist may detect cases of imaginary, feigned, and imputed poisoning. It is by no means easy to lay down rules for the investigation of cases suspected to be of such a kind. But an attempt will be made to state the leading points to be attended to, and to illustrate them by the circumstances of a few examples of each variety.

Imaginary poisoning should rarely be the occasion of deception or embarrassment. The same wandering of the imagination which has led to a belief of injury from poison, will commonly also lead to such extravagant notions relative to the mode of administration and the symptoms, as will infallibly point out the true nature of the case to one who is well acquainted with the real effects of poisons. It is easy, nevertheless, to conceive cases which may be embarrassing; and certainly, in every instance, the physician should proceed in his inquiries with caution.

It appears to me that in the first place, without seeming to take up at once the conviction of his patient, he should scrupulously abstain from treating it lightly, and should on the whole act rather as if he suspected poison had been given. Allowing his patient therefore apparently credit for the truth of his suspicions, the medical attendant should request him to give a full history of existing symptoms, of their origin and progress, of their relation in point of time to various meals, and of the mode and vehicle in which the supposed poison was administered. No unprofessional person can possibly go through such a narrative, without stating many circumstances which are wholly irreconcilable with the idea of poisoning generally, and still more of the administration of a particular poison.

I have met with two instances of imaginary poisoning, the nature of which was thus at once made obvious by a host of impossibilities in the narrative of the patient. One of these may be here given as an example. An elderly lady, who had certain expectancies of the death of a relation, conceived that the family of her relative had resolved to defraud her of her supposed rights. She afterwards imagined that an attempt was made to poison her, and camphor was the poison she fixed on as the article which had been administered. In its general or moral particulars the narrative was all plausible and suspicious enough; but unluckily for its consistency, she stated that the poison could only have been given in wine,—that she did not remark any particular taste in the wine,—that her illness did not begin till the day after she took it; and although she alleged, without any leading question on my part, that camphorous perspiration was exhaled on the subsequent day, the whole train of symptoms differed entirely in every other respect from a case of poisoning, and resembled closely in their origin and progress a case of slight general fever. The incompatibility of her story with the idea of poisoning with camphor will be readily understood by referring to what is afterwards said of the effects of that substance.

Feigned or pretended poisoning is more apt to escape suspicion, and when suspected is commonly more difficult to develope satisfactorily; for the actor has it in his power to lay his plans with care, and even to become acquainted with the properties of the poisons whose effects he intends to feign. Still he can rarely enact his part so well as to deceive a skilful physician both by existing symptoms and by his history of their origin and progress; much less can he contrive his scheme so adroitly that it shall not be unfolded by the refinements of chemical analysis.

The investigation of such a case will be directed of course in the first instance to the state and progress of the symptoms. Here, as in imaginary poisoning, it is of moment to conceal from the individual the suspicion entertained of his falsehood. For even if a person who has actually taken poison knows he is unjustly suspected of feigning, it is not improbable that he might try to mend his story with impossibilities, and so lead the physician into error. In a case of feigned poisoning an excellent mode of investigation is, after hearing out the individual’s own story, to put a number of questions involving an alternative answer, one alternative being compatible and the other incompatible with the alleged nature of his illness. No unprofessional person can stand such a system of interrogation, if skilfully pursued. Not only will his answers be often wrong; but likewise his manifest perplexity how to answer will of itself supply evidence of falsehood.

In the next place, great attention must be paid to the chemical analysis. A person who feigns poisoning will commonly produce the poisoned remains of a dish, or some other article, which he represents himself to have swallowed. Sometimes the substance contained in it will prove on analysis not to be poison at all, as in an instance I remember reading some years ago in a London newspaper of pretended poisoning with arsenic, where the dregs of a bowl of gruel contained, not arsenic, but finely pounded glass. Sometimes the quantity of a real poison contained in the remains of a dish may indicate, in what is said to have been swallowed, a portion wholly incompatible with the mildness or severity of the symptoms. Sometimes the vomited matter, even the matter first vomited, may not contain any of the alleged poison. Sometimes poison found in matter alleged to have been vomited may yield compounds during analysis which are not animalized, showing that it never was in the stomach. Sometimes the quantity of poison contained in such matter may be greater than that alleged to have been taken. Sometimes the quantity contained in the first matter vomited may be less than that contained in what is vomited or said to be vomited subsequently. By these and many other such inconsistencies the falsehood of the story may be unequivocally unfolded.

The following example will illustrate some of the rules now laid down. A young married female, in the seventh month of pregnancy, having been discovered by her friends to be secretly addicted to dram-drinking, appeared to be much annoyed in consequence of the discovery; and one evening was found apparently very ill by her husband on his return from work. She represented that she had taken arsenic with a view to self-destruction, that she was in great torture, and that she was sure she must soon die. It was accordingly found, on reference to a neighbouring apothecary, that she had the same forenoon purchased about a drachm and a half of arsenic for the pretended purpose of poisoning rats; and in the bottom of a teacup, in which she said she mixed it, there was left a small quantity of white powder, that proved on analysis to be pure oxide of arsenic. Notwithstanding these strong facts, the mildness of the symptoms and the composure with which she complained of her tortures led her friends to suspect she was feigning. On investigating her case I first ascertained, in farther corroboration of her story, that the powder was nowhere to be found. But she then stated in reply to questions involving an alternative answer, that the arsenic had a sour taste, and that the pain began in the lower part of the belly, and spread upwards. She likewise said that she vomited a mouthful or two into a chamber-pot twenty minutes after taking the poison; that she vomited no more till the apothecary was sent for, who gave her emetics of sulphate of zinc, carefully preserving the discharges; and that she only vomited when emetics were given. When I first saw her, five hours after the alleged date of the taking of the arsenic, the skin was warm and moist, the face full and flushed, the pulse frequent and firm, the muscular strength natural. The chamber-pot contained only a small quantity of the fæces of a child and apparently a little water, but no vomited matters, and no white powder. The fluid discharged in presence of the apothecary was found on careful analysis to contain a large quantity of zinc, but not an atom of arsenic. She gradually recovered from the illness under which she laboured at the time I saw her, and in two days she admitted she was quite well, but continued to insist that she had taken the poison.—M. Tartra has related a singular case of the same kind, where a young woman feigned poisoning with nitric acid, and was not detected for several days.[^[136]]

Imputed poisoning differs in general from feigned poisoning only in so far as the symptoms which are feigned are imputed to the agency of another.

The imputation of the crime of poisoning by feigning or actually producing the symptoms, and contriving that poison shall be detected in the quarters where in actual cases it is usually sought for, has been not unfrequently attempted. Two important continental cases have already been referred to for other purposes [pp. [66], [76]]; and I may here relate the heads of two English cases, which are of great interest, and will serve to illustrate the mode of procedure in such circumstances.

The first of these, which I have related elsewhere in detail,[^[137]] is a striking example of the power of science in eliciting the truth, and redounds highly to the credit of Mr. Thackrah, the medical gentleman who conducted the investigation.

Samuel Whalley was indicted at York Spring Assizes in 1821, for maliciously administering arsenic to Martha King, who was pregnant by him. The woman King swore, that the prisoner, after twice trying, but in vain, to prevail on her to take drugs for the purpose of procuring abortion, sent her a present of tarts, of which she ate one and a half,—that in half an hour she was seized with symptoms of poisoning with some irritant poison,—and that she continued ill for a long time after. Mr. Thackrah found arsenic in the tarts that remained untouched, and likewise in some matter that was vomited in his presence after the administration of an emetic, as well as in other vomited matters which were preserved for him between his first and second visits. Her appearance, however, did not correspond with the complaint she made of her sufferings, her pulse and tongue were natural, and on careful investigation the following inconsistencies were farther detected. 1. She said she felt a coppery taste in the act of eating the tarts, a taste which arsenic certainly does not possess. 2. From the quantity of arsenic in the tarts which remained she could not have taken above ten grains, while even after repeated attacks of vomiting, the alleged matter subsequently preserved contained nearly fifteen grains. 3. The matter first vomited contained only one grain, while the matter alleged to have been vomited subsequently contained fifteen grains. 4. The time at which these fifteen grains were alleged to have been vomited was not till between two and three hours after the symptoms began; in which case the symptoms would before that time have been in all probability violent. The prisoner was acquitted, and the prosecutor and another woman who corroborated her deposition afterwards confessed that they had entered into a conspiracy to impute the crime to him, because he had deserted her on finding she was too intimate with other men.

Another case not less interesting in its details was communicated to me by my colleague Dr. Traill, who was consulted by the medical attendant, Mr. Parr of Liverpool. A man accused his sister-in-law of administering poison in his tea. He stated that he was seized with pain in the stomach and uneasiness in the head half an hour after taking the tea; and when visited soon after, the countenance was anxious, the skin pallid, the pulse frequent, the throat red; and while Mr. Parr was examining the throat, a quantity of matter was vomited, containing a white, gritty, crystalline substance, which was afterwards ascertained to be oxalic acid. The following circumstances, however, proved that the poison could not have been given in the tea. The man alleged that he remarked in the very first mouthful an acrid taste, followed by sweetness, which is not the taste of oxalic acid. Notwithstanding this warning, he drank the greater part of the tea. He stated that the poison was dissolved in the tea, yet he vomited some oxalic acid in the solid form. Granting he was mistaken in supposing the whole poison dissolved, the quantity swallowed must in that case have been large; and nevertheless the symptoms were mild, though no vomiting took place for about an hour, and next day he was almost well. Four other individuals had tea at the same time from the same tea-pot, without sustaining any harm; and what remained of the infusion did not contain any oxalic acid. Finally, his niece took what he left of his tea in the cup, without remarking any unusual taste; and in the unwashed cup not a trace of oxalic acid could be detected. It was quite plain, therefore, that the man’s accusation was false; and certain points of general evidence, coupled with the medical facts, afterwards proved that he must have taken the oxalic acid himself.

It has been alleged, that attempts have been made to impute the crime of poisoning by introducing poisonous substances into the body after death; and although I have not been able to find any actual instance of such ingenious atrocity mentioned by authors, it must be acknowledged to be quite possible; and the medical jurist should therefore be prepared for the requisite investigations. Every case may be clearly made out by attending to the relative effects of poisons on the dead and on the living tissues;—a subject which will receive some notice under the head of the principal poisons in common use.

PART SECOND.
OF INDIVIDUAL POISONS.

CHAPTER I.
OF THE CLASSIFICATION OF POISONS.

After the preliminary observations on General Poisoning, I proceed next to treat of Poisons Individually. The subsequent remarks will be confined in a great measure to the most common poisons, which will be examined minutely. The rest being mere objects of curiosity, and hardly ever taken by man either intentionally or by accident, it will be sufficient to point out their leading properties.

It may be well to point out in the first instance the poisons in most general use. These will appear from the following Tables. The first is compiled from a Parliamentary Return of the cases of fatal poisoning brought before the coroners of England in two years ending with 1838.

1.	Arsenical	White arsenic	185
		Yellow arsenic	1
				186
2.	Acids	Sulphuric acid	32
		Nitric acid	3
		Oxalic acid	19
				54
3.	Mercurials	Corrosive sublimate	12
		White mercury	1
		Turbith-mineral	1
		Mercury (?)	1
				15
4.	Other mineral irritants	Tartar-emetic	2
		Sulphate of iron	1
		Chloride of tin	1
		Subacetate of lead	1
		Bichrom. of potash	1
		Percussion powder	1
		Carbonate of potash	1
		Black-ash	1
				9
5.	Veget. irritants	Colchicum	3
		Hellebore	1
		Savin	1
		Cayenne	1
		Castor seeds	1
		Morison pills	1
				8
6.	Anim. irrits.	Cantharides	2
7.	Opium	Opium or Laudan.	180
		Opium & nitric acid	1
		Poppy-syrup	4
		Godfrey’s Cordial	6
		Morphia	1
		Acetate of morphia	1
				193
8.	Hydrocyanic acid	Med. Hydroc. acid	27
		Do. and Laudanum	1
		Ess. oil of Almonds	5
		Bay-leaves	1
				34
9.	Other veget. Narcotics	Nux-vomica	3
		Strychnia	2
		Belladonna	2
		Hemlock	1
		Monkshood	2
		Spirits	4
		Fungi	4
				18
10.	Narcot. gases.	Coal-gas		2
11.	Unascertained			22
		Total		543

In France, in seven years, from 1825 to 1831, inclusive, there were 216 trials for poisoning, at which 273 persons were charged with the crime, and only 102 condemned. In 94 cases occurring between November 1825 and October 1832, the substances employed were as follows.[^[138]]

Arsenic	54
Orpiment	1
Verdigris	7
Corrosive sublimate	5
Fly-powder	3
Tartar-emetic	1
Sulphate of zinc	1
Acetate of lead	1
Cerusse	1
Mercurial ointment	1
Cantharide
Nux-vomica	4
Opium	1
Sulphuric acid	1
Nitric acid	1
Unascertained	5

In the subsequent seven years there were 218 trials, and 153 prisoners condemned. Among 194 of these the following were the poisons used.[^[139]]

Metallic arsenic	5
Arsenious acid	132
Arsenite of copper	1
Compounds of copper	13
Corrosive sublimate	10
Artificial orpiment	3
Sulphate of zinc	1
Tartar-emetic	1
Cerusse	1
Sulphuric acid	5
Nitric acid	2
Muriatic acid	1
Hydrocyanic acid	1
Ammonia	1
Belladonna	1
Opium	3
Morphia	1
Nux-vomica	1
Cantharides	10

In Denmark, in five years ending with 1835, there were 99 cases of poisoning of all sorts, 16 by arsenic, 74 by sulphuric or nitric acid, 4 by potash, 1 by an unascertained caustic substance, 2 by opium, 1 by litharge, and 1 by copper. Only 5 cases, namely, 3 by arsenic and 2 by sulphuric acid, were cases of murder, or attempt to murder.[^[140]]

The classification of poisons has hitherto defied the ingenuity of toxicologists. Formerly it was thought sufficient to arrange them in three great classes, according as they are derived from the mineral, the vegetable, or the animal kingdom. It is evident, however, that the only sound basis of arrangement is their action on the animal economy; for such a classification is the only one which can be useful in practice. Now, when we consider what has been said on their mode of action, or the symptoms produced in consequence of that action, it must at once be perceived, that no system founded on either of these circumstances can be logically correct. It would be very desirable, if their mode of action could be adopted as the basis of arrangement; but both reasoning and experience have proved this to be impracticable. One very distinct class indeed might be formed of purely local poisons, comprehending the mineral acids, the fixed alkalies, and one or two of their chemical compounds. But a vast proportion of the other poisons which act locally have also a general or remote action; and on the other hand there are few of the latter description which do not likewise act locally. Hence if all which possess this double action were arranged in one class, that class would include nine-tenths at least of known poisons; so that, in truth, the labour of classification would still remain to be overcome.

It would be even more fruitless to attempt an arrangement of poisons according to their medium of action; for no sure criterion is known, by which a poison acting through direct transmission of an impulse along the nerves can be distinguished from one that acts by entering the blood.

Neither is the embarrassment of the toxicologist materially less, if he attempts to classify poisons according to the symptoms they induce in man. This is the principle now generally followed, and which in common with others I shall pursue. But the reader will be at no loss to discover that the partitions which separate the classes are exceedingly slight, and that very many poisons might be arranged without impropriety in either of two classes.

The preceding statements show the impossibility of founding a good system of arrangement on the only basis which can be acknowledged philosophical and practical; and consequently, that, as the science of toxicology now stands, we must altogether despair of forming one that shall be even moderately satisfactory.

On the whole I see no reason for deviating from the classification adopted in the first edition of the present work, being a modification of that previously followed by Professor Orfila. In this classification poisons are divided into irritants, narcotics, and narcotic-acrids.

The class of irritants includes all poisons whose sole or predominating symptoms are those of irritation or inflammation; the narcotics those which produce stupor, delirium, spasms, paralysis, and other affections of the brain and nervous system; and the narcotico-acrids those which cause sometimes irritation, sometimes narcotism, sometimes both together. Some writers still adopt a fourth class, called septics, because they give rise to putrefaction in the living body. But modern physiology will scarcely sanction the continuance of such a class of poisons. For assuredly no substance can cause putrefaction in the living body.

CHAPTER II.
CLASS FIRST.
ON IRRITANT POISONS GENERALLY.

The class of irritant poisons comprehends all whose sole or predominant action consists in exciting irritation or inflammation. That is, it comprises both those which have a purely local, irritating action, and likewise many which also act remotely, but whose most prominent feature of action still is the inflammation they excite wherever they are applied.

This subject will be introduced with an account of the general symptoms and morbid appearances caused by the irritants, and a comparison of these with the symptoms and morbid appearances of the natural diseases which are chiefly liable to be confounded with irritant poisoning, or mistaken for it.

Section I.—Of the Symptoms of the Irritant Poisons, compared with those of natural diseases.

The symptoms caused by the irritating poisons, taken internally, are chiefly those of violent irritation and inflammation of one or more divisions of the alimentary canal.

The mouth is frequently affected, especially when the poison is easily soluble, and possesses a corrosive as well as irritating power. The symptoms referrible to the mouth are pricking or burning of the tongue, and redness, swelling and ulceration of the tongue, palate, and inside of the cheeks.

The throat and gullet are still more frequently affected; and the affection is commonly burning pain, sometimes accompanied with constriction and difficulty in swallowing, and always with redness of the visible part of the throat and gullet.

The affection of the throat and mouth precedes every other symptom when the poison is an active corrosive, and more particularly when it is either a fluid poison or is easily dissolved. Nay, sometimes burning pain of the mouth, throat, and gullet occurs during the very act of swallowing.—On the contrary if the poison is soluble with difficulty, and is only an irritant, not a corrosive, and still more if it is only one of the feebler irritants, the throat is frequently not affected sooner than the stomach, occasionally not at all.

The stomach is the organ which suffers most invariably from the operation of irritant poisons. The symptoms referrible to their operation on it are acute and general burning pain, sometimes lancinating or pricking pain,—sickness, vomiting, tenderness on pressure, tension in the upper part of the belly, and occasionally swelling. Of these symptoms the sickness is generally the first to develope itself. In the instance of corrosive irritants pain commonly commences along with it. The matter vomited is at first the contents of the stomach, afterwards tough mucus, streaked often with blood and mingled with bile, frequently clots of purer blood. The powerful corrosives affect the stomach the moment they are swallowed; irritants which are either liquid or very soluble also affect it very soon; but the more insoluble irritants, such as arsenic, generally do not begin to act till half an hour or even more than a whole hour has elapsed.—The stomach may be affected without any other part of the alimentary canal participating in the injury; but much more frequently other parts suffer also, and in particular the intestines.

The action of irritant poisons on the intestines is marked by pain extending over the whole belly, sometimes even to the anus. This pain, like that of the stomach, is often a sense of burning; but it is also frequently a pricking or tearing pain, and still more frequently a twisting, intermitting pain like that of colic. It is seldom attended with much swelling, but often with tension, and tenderness of the whole belly; and at times the inflammatory state of the mucous coat of the intestines is clearly indicated by excoriation of the anus and prolapsus of the rectum, which is of a bright red colour. The pain of the bowels is most generally attended by purging, rarely with constipation, frequently with tenesmus. The matter discharged, after the alimentary and feculent contents have passed, is chiefly a mucous fluid, often abundant, often also streaked with blood or mixed with considerable quantities of blood. In some cases the intestines are affected when no other part of the alimentary canal suffers, not even the stomach. But much more generally the stomach and intestines are affected together.

In a few very aggravated cases of poisoning with the irritants the whole course of the alimentary canal, from the throat to the anus, is affected at one and the same time.

The symptoms now briefly enumerated are accompanied in almost every instance with great disturbance of the circulation—quick, feeble pulse—excessive prostration of strength,—coldness, and clammy moisture of the skin.

The other symptoms, which are often united with the preceding, do not belong to the irritants as a class. Perhaps, however, among the symptoms of the class may be mentioned those of irritation and inflammation of the windpipe and lungs, and those of irritation in the urinary organs. A great number of the irritant poisons cause hoarseness, wheezing respiration, and other signs which indicate the spreading of the inflammation of the throat to the windpipe: some likewise cause darting pains throughout the chest: and not a few are very apt to cause strangury and other signs of inflammation of the urinary passages.

Of the effects of the irritants when applied externally little need be said at present. Their most striking external symptoms will be noticed under the head of one of the orders of this class, the vegetable acrids. In the chapter on the local action of poisons some account was given of the several effects which are produced by the application of poisons to the skin. It is there stated that some produce merely redness, that others cause blistering, that others bring out a crop of deep-seated pustules, that others corrode the tissues chemically, and so give origin to a deep slough, and that others excite spreading inflammation of the cellular tissue under the skin and between the muscles.

Such is a general view of the symptoms caused by the irritant poisons. This topic will be afterwards taken up in detail under the head of the several species. At present an important subject remains for consideration, namely, the natural diseases whose effects are apt to be mistaken for the effects of poison. The remarks now to be made might be extended to many diseases. In fact, they might be extended to all which prove fatal suddenly, for all such diseases are apt in peculiar circumstances to give rise to a suspicion of poisoning. But those only will be here noticed which occasion the greatest embarrassment to the medical jurist, and which are most likely to come under his review in courts of law. They are the following:—Distension and rupture of the stomach; rupture of the duodenum, biliary ducts, uterus, or other organs in the belly; the effects of drinking cold water; bilious vomiting and common cholera; malignant cholera; inflammation of the stomach; inflammation and perforation of the intestines; inflammation of the peritonæum; spontaneous perforation of the stomach; melæna and hæmatemesis: colic, iliac passion and obstructed intestine.

1. Distension of the Stomach.—Mere distension of the stomach from excessive gluttony may cause sudden death. Generally indeed the symptoms and appearances in the dead body show that death is the consequence of apoplexy; but sometimes not. In order to preserve the continuity of the succeeding remarks on the diseases of the stomach which imitate poisoning, it may be useful to consider in the present place all the varieties of the effects of distension.

Excessive distension of the stomach, then, sometimes causes sudden death by inducing apoplexy, which is commonly of the congestive kind,—that is, without rupture of vessels. Mérat has related an instructive case of this kind. A man in good health, while greedily devouring an excellent dinner, became suddenly blue and bloated in the face; a clammy sweat broke out over his body; and he died almost immediately. On dissection the stomach was found enormously distended with food, and the vessels of the brain were so gorged, that the brain appeared too large to be contained within the skull.[^[141]]

There is reason, however, to suppose that death from distension is the consequence not always of apoplexy,—but sometimes of an impression on the stomach itself. Sir Everard Home relates the case of a child, who, being left by its nurse beside an apple-pie, was found dead a few minutes afterwards, and in whose body no appearance of note could be discovered, except enormous distension of the stomach with the pie.—A still more distinct case in point forms the subject of a medico-legal report by Wildberg. A corpulent gentleman died suddenly fifteen minutes after dinner; and as he lived on bad terms with his wife, a suspicion arose that he had been poisoned. His wife said that he fell asleep immediately after dinner; but had not slept many seconds, when he suddenly awoke in great anguish, called out for fresh air, exclaimed he was dying, and actually expired before his physician, who was instantly sent for, could arrive. Wildberg found the stomach so enormously distended with ham, pickles, and cabbage-soup, that, when the belly was laid open, nothing could be seen at first but the stomach and colon. Some white powder, found on the villous coat of the stomach, was at first suspected to be arsenic; but it proved on analysis to be merely magnesia, which the gentleman had been in the habit of taking frequently. The diaphragm was pushed high into the chest by the distended stomach. There was not any particular congestion in the brain. Wildberg very properly ascribed death to simple over-distension of the stomach.[^[142]]—In all such cases the symptoms may be suspicious; but when carefully considered they can scarce be said to resemble closely the effects of irritant poisoning; and at all events the appearances in the dead body will at once distinguish them.

2. Rupture of the Stomach is not a common occurrence; but it sometimes imitates in its symptoms the effects of the irritant poisons.

It is generally the consequence of over-distension, combined with efforts to vomit. The cause of it seems to be, that the abrupt turn which the gullet makes in entering an excessively distended stomach acts as a valve, so that the contents cannot be discharged by vomiting. A case of this kind is related by M. Lallemand in his Inaugural Dissertation at Paris in 1818.[^[143]] A woman convalescent from a tedious attack of dyspepsia, being desirous to make amends for her long privations as to diet, ate one day to satiety. Ere long she was seized with a sense of weight in the stomach, nausea, and fruitless efforts to vomit. Then she all at once uttered a piercing shriek, and exclaimed that she felt her stomach tearing open; afterwards she ceased to make efforts to vomit, soon became insensible, and in the course of the night she expired. In the fore part of the stomach there was a laceration five inches long; and a great deal of half-digested food had escaped into the cavity of the abdomen. The coats of the body of the stomach were healthy; but the pylorus or opening into the intestines was indurated; which had been the cause of her dyspepsia.

In other cases of death from rupture the laceration is caused not by the accumulation of food, but by the accumulation of gases arising from depraved digestion, constituting a disease almost the same as that which attacks cattle that have fed on wet clover. A singular example of this rare affection, in which death was preceded by the symptoms of irritant poisoning, has been noticed by Professor Barzelotii.[^[144]]—Another case, which appears to have been of the same kind, is mentioned in a late French journal. A child, a twelvemonth old, after eating cabbage-soup, died during the night unperceived by its mother. On the body being examined, a great quantity of fetid gas escaped from the abdomen, and a smooth laceration like an incised wound, three inches in length, was found in the lesser arch of the stomach.[^[145]]

In other cases, however, it is not easy to say what occasions the injury. An instance, for example, has been related, where the accident followed the drinking of a little shrub and water. The individual, a man of middle age, who had been long liable to fits of severe pain in the stomach, going off with vomiting, was suddenly seized the day after one of his fits with violent pain in the epigastrium, extreme tenderness and tension of the muscles, and for a short time with violent vomiting. In seventeen hours he expired. On dissection a dark-brown fluid was found in the cavity of the belly, and the fore part of the stomach presented a laceration four inches long. There were likewise several lacerations, one of them three inches long, which intersected the peritonæal coat alone.[^[146]] A case probably similar in nature has been described by Dr. Roberts of London, that of a man who died of convulsions in five hours, and presented after death a long rent in the stomach, with escape of its contents into the general cavity of the belly.[^[147]]

Another rare variety of rupture of the stomach must also be particularly noticed, because the course of the symptoms imitates very closely a case of poisoning with the irritants. It is partial rupture,—or laceration of the inner coat only. A very interesting case of that description has been related by Mr. Chevallier. A youth of fourteen, on the evening after a Christmas feast, at which he ate and drank heartily, was attacked with violent and frequent vomiting. Next morning he said he felt as if the blood in his heart was boiling, he was unable to swallow, the pulse became irregular, and pressure on the heart or stomach gave him excruciating agony. These symptoms continued till the following day, when he vomited two pounds of blood at successive intervals, and soon afterwards expired. The inner coat of the stomach was torn in many places, and that of the duodenum was lacerated almost completely round. No other disease existed in the bowels or elsewhere.[^[148]]

Some of the cases now mentioned could hardly be distinguished from the effects of certain irritant poisons by the symptoms only. But the morbid appearances in the stomach will at once determine their real nature.

Rupture of the stomach, it may be observed, does not always occasion the symptoms hitherto related. Sometimes it causes instant death. Thus a healthy coal-heaver in London, while attempting to raise a heavy weight, suddenly cried out, clapped his hand over his stomach, drew two deep sighs, and died on the spot. On dissection a lacerated hole was found in the stomach, big enough to admit the thumb; and the stomach did not contain any food.[^[149]] This case, along with those of Dr. Roberts and Mr. Weekes, will show that rupture may take place without previous distension.

3. Rupture of the Duodenum is a very rare accident from internal causes. The following instance resembles considerably the symptoms of irritant poisoning. A gentleman, 48 years old, quarrelled violently with another while playing billiards immediately after dinner. Soon afterwards he was seized suddenly with violent pain in the stomach, vomiting, cold extremities, and a failing pulse; and he died very soon. The mucous coat of the duodenum was found much inflamed, and four inches and a half from the pylorus there was a lacerated hole involving a third of the circumference of the gut.[^[150]]

4. Under the next head may be classed rupture of the other organs of the belly. Rupture of the Biliary Ducts for example, an extremely rare accident, has been known to imitate the symptoms of irritant poisoning, as the following case will show.—An elderly lady, after a slight attack of jaundice, was seized with violent pain in the stomach, and vomiting recurring in frequent fits, and in seventeen hours with extreme tenderness, tension of the muscles, coldness of the skin, and failure of the pulse. She expired in twenty-four hours; and after death the hepatic duct was found torn across, a gall-stone lay at the opening of the cystic duct, the peritonæum was here and there inflamed, and three pounds of blood and bile were effused into the cavity of the abdomen.[^[151]]—The nature of such cases will be always apparent on dissection, but by no means always from the symptoms.

In like manner rupture of the uterus or its appendages may in certain circumstances occasion similar symptoms, and so be mistaken for the operation of poison. A striking example of the kind once came under my notice. A middle-aged woman much addicted to drinking, and on that account living on indifferent terms with her husband, was suddenly seized at two in the afternoon with pain in the belly, afterwards with vomiting and purging, then with extreme exhaustion and coldness of the extremities; and at ten in the evening she expired. A suspicion of poisoning having arisen in the neighbourhood, a judicial inspection was ordered by the sheriff of Linlithgowshire, where the case happened; and the examination was entrusted to her medical attendant, Mr. Robertson, and myself. On inquiry, it was found that she had taken nothing whatever after breakfasting at eight in the morning, six hours before; and farther, that the pain had begun violently in the lower part of the belly. These two circumstances alone were almost, if not altogether, incompatible with the idea of irritant poisoning having been the occasion of death. But all doubt was completely removed by the inspection of the body; for the lower part of the belly was filled with a great quantity of clotted blood, which had proceeded from the rupture of a Fallopian conception.

5. The next accident which may be noticed on account of its being liable to be mistaken for the effects of poison is sudden death from drinking cold water.

In Britain the most common form of death from this cause appears to have been instant death, arising from the impression on the stomach. It is not an uncommon thing for people to drop down instantaneously and die on the spot, in consequence of drinking freely of cold water or other fluids while over-heated.[^[152]] There is an interesting report on a case of this kind by Pyl in his Memoirs and Observations. The individual had been quarrelling with a companion, and in the height of a fit of violent passion swallowed a glass of beer; when he dropped down senseless and motionless, and died immediately. His wife suspecting the administration of poison, demanded a judicial inquiry; but nothing was found in the body to account for death. Pyl therefore came to the conclusion that the man died from the sudden impression caused by the cold beer.[^[153]] Dr. Currie, after quoting several instances of the like kind, relates the following remarkable case which occurred to himself. A young man, having just sat down, panting and bathed in sweat, after a severe match at tennis, drank greedily from a pitcher of water fresh drawn from a neighbouring pump. Suddenly he laid his hand on his stomach, bent forward, became pale, breathed laboriously, and in a few minutes expired.[^[154]]

But when combined with exposure to a burning sun, as in hot climates, drinking cold water when the body is over-heated seems often to excite along with irritation in the stomach congestive apoplexy. Dr. Watts has given a good account of these effects as they occurred in the neighbourhood of New York during the hot season of 1818. During the summer of that year the thermometer often stood in the shade so high as 92°; and the labourers in consequence could not be restrained from drinking frequently and excessively of cold water. Many were attacked with pain in the stomach, sickness, giddiness, and fainting; next with difficult breathing, and rattling in the throat; then with apoplexy; and not a few perished.[^[155]] These symptoms are very like the effects of some narcotico-acrid poisons.

Lastly, drinking cold water sometimes causes symptoms more nearly allied to those of the pure irritants. Thus some persons, on eating ices, or drinking iced-water, or cold ginger-beer in the hot days of summer, are attacked with violent colic. Others in the like circumstances are attacked with violent fits of vomiting.[^[156]] Haller has even mentioned an instance of a man, who after swallowing a large draught of cold water while over-heated, was seized with symptoms of acute gastritis, and died in fifteen days: and in the dead body the stomach was found gangrenous and ulcerated at its fundus.[^[157]] M. Guérard relates a similar case, that of a quarter-master who, swallowing iced-beer after a hurried journey in a hot day, was attacked in six hours with shivering, then with heat and tightness in the pit of the stomach, vomiting of every thing he took, anxiety, thirst and frequency of the pulse; next with extreme prostration, cessation of pain, hiccup, and lividity of the face; and he expired in five days. Signs of inflammation were found in the stomach, such as great redness internally, with spots of extravasation, and a blackish matter like what he vomited.[^[158]] Cholera has also been sometimes referred to the same cause. In the hot summer of 1825 it was remarked that a great number of persons who used to frequent a particular coffee-house in the Palais-Royal at Paris, and the owner among the rest, were severely affected with cholera. Poison being suspected to be the cause, a judicial inquiry was instituted. It was proved, however, that similar accidents had been observed at other coffee-houses, in other cities, and likewise in former hot seasons; and when the whole medical evidence was referred to a commission of physicians and chemists, they gave their opinion, that the disease was owing to the incautious use of ices and iced-water in an unusually hot summer.[^[159]] Perhaps cholera arising thus may prove fatal. The following extraordinary case, which appears to have been of this nature, was communicated to me by the late Dr. Duncan, junior. A bookbinder in this city, previously in excellent health, rose one morning at six to kindle his fire, and took a large draught of cold water from a pitcher used in common by the whole family. He went immediately to bed again, complaining of pain in the pit of the stomach, and extreme anxiety, and affected with incessant vomiting. In twelve hours he died without any material change in the symptoms, and no disease whatever could be detected in the dead body. Dr. Duncan satisfied himself from general circumstances, that poisoning was quite out of the question; so that, however extraordinary it may appear, his death could be accounted for in no other way than by ascribing it to the cold water.—Hoffmann says he was acquainted with instances where fatal inflammatory fever was induced by drinking too freely of cold water, and a suspicion of poisoning in consequence excited.[^[160]]

6. Of Bilious Vomiting and Simple Cholera.—Of all the diseases which are apt to be confounded with the effects of the irritant poisons, there is none which it is of so much importance that the medical jurist should be able to distinguish as cholera. A trial for poisoning with the common poisons hardly ever occurs, but an attempt is made to ascribe death to that disease; for it is very frequent, and its symptoms bear a close resemblance to those of the principal poisons of the class we are now considering.

It is unnecessary to give here a detailed account of the symptoms of simple cholera. There is the same burning pain in the stomach and bowels as in irritant poisoning, the same incessant vomiting and frequent purging, the same tension and tenderness of the belly, the same sense of acridity in the throat, and irritation in the anus, the same depression and anxiety, the same state of the pulse.

It would be wrong, however, to infer from these resemblances that the two affections are always undistinguishable. Some cases of irritant poisoning certainly cannot be distinguished by their symptoms from cholera. Many other cases are similarly circumstanced, because their particulars cannot be accurately collected. But there is no doubt that in others the distinction between poisoning and cholera may be drawn by the physician who has been able to ascertain the symptoms in detail. At present those points of difference only will be noticed which relate to the irritants as a class; others will be mentioned under the head of poisons individually.

The first difference is, that in cholera the sense of acridity in the throat does not precede the vomiting, as it sometimes does in poisoning. In cholera this sensation is caused by the vomited matter irritating the throat, or perhaps by the irritation in the stomach being propagated upwards by continuity of surface. But, whatever may be its cause, it is certain that the sense of acridity or burning sometimes remarked in cholera never begins before the vomiting. In many cases of poisoning, though certainly not in all, it is the first symptom.—The next difference is, that in cholera the vomiting is never bloody. I have been at some pains to investigate this point: and I have been unable to find any instance of the cholera of this country, which has been accompanied with sanguinolent vomiting; neither is such a symptom mentioned in any accounts I have read of malignant cholera. This article of diagnosis will, of course, be open to correction from the experience of other practitioners. Lastly, a material difference is, that the simple cholera of this country very seldom proves fatal so rapidly as poisoning with the irritants usually does. Death from irritant poisoning is on the whole seldom delayed beyond two days and a half, and frequently happens within thirty-six hours, sometimes within six hours, or even less. Malignant cholera frequently proves fatal in as short a time; but with regard to the cholera of this country, I believe it may be laid down as a rule hitherto unshaken by all the controversy to which the subject has given rise,—that death is not often caused by it at all, and that death within three days is very rare indeed. A few cases of death within that period, nay, even within twelve hours, have certainly occurred; but their great rarity is obvious from the fact, that many practitioners of experience have not met with a single instance, and others with only one case in the course of a long practice. Dr. Duncan, senior, mentioned to me a case, the only one of the kind he had met with, which commenced soon after the individual ate a sour orange in the Edinburgh theatre, and which proved fatal in twelve hours. Dr. Duncan, junior, also met with a single case, which was the instance already noticed of cholera produced by drinking cold water. Dr. Abercrombie also once, and once only, met with a case fatal within two days.[^[161]] Mr. Tatham, a late writer on this subject, met with an instance which proved fatal in twelve hours.[^[162]] Dr. Burne of London has likewise related an instance of death within fifteen hours occurring in a child.[^[163]] And I was informed in 1831 of a case at Leith which ended fatally in twenty-six hours, and was at first supposed by the unprofessional inhabitants of the place to be an instance of epidemic or malignant cholera. My colleagues, Drs. Home, Alison, and Graham, never met with an instance fatal in so short a time as two or three days; at a meeting of the Medico-Chirurgical Society of this city, none of the members present could remember to have seen such a case;[^[164]] and of the witnesses who were brought to swear to this point on a well-known trial, all of them physicians of extensive practice, not one could depose that such a case had ever come within his personal observation.[^[165]] It has been stated however in a controversial publication written by the late Dr. Mackintosh of this place, that the author had seen many cases fatal within the period now mentioned.[^[166]] This is incomprehensible. For my own part, I cannot help repeating, as the result of the whole inquiry, that simple cholera rarely causes death in this country, in the period within which irritant poisoning commonly proves fatal,—that, consequently, every case of the kind will naturally be apt to lead, in peculiar circumstances, to suspicion of poisoning,—and that in charges of poisoning, rapid death under symptoms of violent irritation in the alimentary canal, like those of cholera, must always be considered an important article of a chain of circumstantial or presumptive evidence.

7. Of Malignant Cholera.—The history of this disease affords a fair promise that, in so far as British practitioners are concerned, it may ere long be excluded from the list of those which imitate irritant poisoning. Meanwhile, however, malignant cholera must be allowed to bear, in its essential symptoms and their course, a marked resemblance to poisoning with the irritants. So much indeed is this the case that some authors have actually compared its phenomena to the effects of arsenic, tartar-emetic, and other powerful acrids. In many cases the two affections are undoubtedly not so distinguishable by symptoms as to warrant a physician to rely on the diagnosis in a medico-legal inquiry. But in many other instances the distinction may be drawn satisfactorily. Thus the uneasiness in the throat which sometimes attends cholera never precedes the vomiting. The vomiting in cholera is never bloody. The colour and expression of the countenance and whole body are peculiar. In frequent instances the early signs which resemble poisoning are followed by a secondary stage, sometimes of simple coma, sometimes of typhoid fever, which a practised person may easily distinguish from the secondary phenomena produced by some irritants. Lastly, no mistake can arise where the patient, before presenting the symptoms common to both affections, experiences violent burning pain or certain tastes, during or immediately after the swallowing of food, drink, or some other article.

8. Of Inflammation of the Stomach.—Chronic inflammation of the stomach is a common disease; which, however, on account of the slowness of its course, is not liable to be confounded with the ordinary effects of irritant poisons. Acute inflammation, on the contrary, follows precisely the same course as that of irritant poisoning. But great doubts may be entertained whether true acute gastritis ever exists in this country as a natural disease. Several of my acquaintances, long in extensive practice, have stated to me, that their experience coincides entirely with that of Dr. Abercrombie, who observes he has “never seen a case which he could consider as being of that nature.”[^[167]] An important observation of the same purport has been made by M. Louis, one of the most experienced and accurate pathologists of the present time. He says, that during six years’ service at the hospital of La Charité, during which he noticed the particulars of 3000 cases and 500 dissections, he did not meet with a single instance of fatal primary gastritis. The disease only occurred as a secondary affection or complicating some other disease which was the cause of death.[^[168]] So far as I have hitherto been able to inquire among systematic authors, the descriptions of idiopathic acute gastritis appear to have been taken from the varieties caused by poison.

The following are the only specific accounts I have hitherto met with of an affection of the nature of idiopathic acute gastritis; and the reader will be at no loss to perceive that in each of them it admits of being viewed differently. The first two are the cases of inflammation referred by Haller and Guérard to drinking cold water incautiously [p. [100]]. The next is a remarkable incident related by Lecat, and occurring in 1763. A girl, nineteen years old, was attacked while in good health with shivering, faintness, acute pain in the belly, cold extremities and imperceptible pulse; and she died in sixteen hours. The stomach was found red, and checkered with brownish patches and gangrenous pustules (probably warty black extravasation): yet it was supposed to have been ascertained that she had not taken any thing deleterious.[^[169]] This narrative is certainly to appearance pointed. But when it is added, that the girl’s mother was attacked about the same time with precisely the same symptoms and died in four hours, I think the reader, when he also considers the imperfect mode in which chemical inquiries were then conducted, will by no means rest satisfied with Lecat’s assurance that nothing deleterious was swallowed. The last is an equally singular case given by Dr. Hastings, of Worcester, where poisoning with cantharides was suspected. A young lady, liable to indigestion, but at the moment in better health than usual, was attacked with sickness before breakfast and after it with vomiting. Three days elapsed before she was seen by her medical attendant, who found her sinking under incessant vomiting, severe pain in the loins, strangury, bloody urine, and swelling of the clitoris, attended with red extravasation of the eyes, and a red efflorescence on the skin. Death followed next day amidst convulsions; and there was found in the dead body extravasation of blood between the kidneys and their outer membrane, into the pelvis of each kidney, and into the bladder,—redness of the bronchial membrane, and gorging of the air-cells with blood,—and general redness of the inside of the stomach, with numerous extravasated spots in the submucous coat.[^[170]] It seems to have been clearly proved at the coroner’s inquest that poisoning was here out of the question. But the case appears rather to have been one of renal irritation or inflammation than of gastritis, and the affection of the stomach secondarily merely.

The question as to the possibility of acute gastritis being produced by natural causes is one of very great interest to the medical jurist. For its possible occurrence is the only obstacle in the way of a decision in favour of poisoning, from symptoms and morbid appearances only, in certain cases by no means uncommon, which are characterised by signs of violent irritation during life, early death, and unequivocal marks of great irritation in the dead body, namely, bright redness, ulcers, and black, granular, warty extravasation. In regard to these effects, it may with perfect safety be said, that they can very rarely indeed all arise from natural causes; and for my own part, the more the subject is investigated, the more am I led to doubt whether they ever arise in this country from any other cause than poison. The possible occurrence of a case of the kind from natural causes must be granted. But this concession ought not to take away from the importance of the contrary fact as one of the particulars of a chain of circumstantial proof.

In whatever way the fact as to the existence of idiopathic acute gastritis may eventually be proved to stand, an important criterion of this disease, as of cholera, will be that the sense of burning in the throat, if present at all, does not precede the vomiting.

9. Inflammation of the Intestines in its acute form is more common than inflammation of the stomach, as a natural disease. It is generally accompanied, however, with constipation of the bowels. Acute enteritis, unless we choose with some pathologists to consider cholera as of that nature, is very rarely attended with purging.

There is a variety of intestinal inflammation, observed only of late by pathologists,[^[171]] but now well known, which bears a close resemblance to the effects of the irritants. It is a particular variety of ulceration commonly situated near the end of the small intestines, accompanied at first with trifling or insidious symptoms, and terminating suddenly in perforation of the gut. It begins with tubercular deposition under the mucous membrane in roundish patches. Then an ulcer appears on the middle of one or more of these patches, gradually spreads over them, and at the same time penetrates the other coats. At last when the peritoneal coat alone is left, some trifling accident ruptures it, the fæcal matters escape into the sac of the peritonæum, and the patient dies in great agony in the course of one or two days, or in a few hours. Such cases, if not distinguished by the symptoms, will be at once recognized by the morbid appearances. Perforation of the intestines, with similar symptoms, also takes place without the previous tubercular deposit, by simple ulceration of the coats.[^[172]]

Another form of intestinal inflammation may also be here particularized, because it imitates the effects of the irritants in the cases in which they prove slowly fatal. It is a form of aphthous ulceration of the mucous membrane of the alimentary canal, which appears to affect almost every part of it from the throat downwards, and begins commonly in the throat. I once met with a remarkable case in which it appeared in the form of little white ulcers in the back of the throat, and gradually travelled downwards to the stomach and from that to the intestines,—being characterized by burning pain in every one of its seats, and successively by difficulty of swallowing, by sickness, vomiting, and tenderness of the stomach, and finally by purging. Such cases resemble the slow forms of poisoning with arsenic. But they differ in attacking the several divisions of the alimentary canal in turn, while in the examples of poisoning with arsenic now alluded to, the whole canal from the mouth to the anus is affected simultaneously. Dr. Abercrombie has described a similar disorder, which he appears to have occasionally seen affecting both the stomach and intestines at the same time; but he seems to doubt whether it ever occurs as an idiopathic disease, or independently of some co-existing or preceding fever or local inflammation.[^[173]]

10. Inflammation of the Peritonæum, or lining membrane of the belly, will not require many remarks. When acute, it is rarely attended in its early stage by vomiting; rarely also by irregular action of the intestines, and never by diarrhœa; and it is at once distinguished in the dead body by unequivocal marks of peritonæal inflammation, which are very seldom caused by irritant poisons.[^[174]]

11. The subject of Spontaneous Perforation of the Stomach is an important topic for the medical jurist, because both the symptoms before death and the appearances in the dead body are occasionally very like the effects of some of the most active irritant poisons. The following is a statement of the most material facts hitherto ascertained on this subject; but it must be premised that a good deal of obscurity still hangs over some parts of it.

Spontaneous perforation of the stomach is of three kinds. One is the last stage of some varieties of scirrhus. The indurated membrane ulcerates, the ulcer penetrates first the villous, then the muscular, and at last the outer or peritoneal coat, so that the contents of the stomach escape into the belly. The symptoms of the perforation are a sense of something giving way in the pit of the stomach, acute pain gradually extending over the whole abdomen, great tenderness and tension, excessive prostration, and death commonly within twenty-four hours. The symptoms which precede the perforation in general clearly indicate organic derangement of the stomach, namely, aggravated dyspepsia of long standing. Several cases of this description may be seen in a thesis by M. Laisné,[^[175]] a pupil of Professor Chaussier. Two characteristic cases have been published by Dr. Crampton;[^[176]] and Mr. Alfred Taylor has referred to several others, the stomachs of which are preserved in Guy’s Hospital Museum, and gives the particulars of some which had occurred in the practice of that institution or to his friends.[^[177]] Occasionally no symptom exists prior to the perforation, as in an instance related by Dr. Kelly of a stout healthy servant, who was suddenly seized with excruciating pain in the stomach and expired in eighteen hours, and in whose body the stomach was found perforated in the middle of an extensive thickening and induration of the villous coat.[^[178]]

The second variety of perforation takes place by simple ulceration without previous scirrhus. In one of Dr. Crampton’s papers will be found some remarks by Mr. Travers, along with a case of this kind. The subject of it was a man of a strumous habit, who enjoyed good health, till one day at dinner he was suddenly attacked with acute pain in the pit of the stomach, and died in thirteen hours. The stomach was found perforated in the centre of a superficial ulcer of the mucous coat, occupying two-thirds of the ring of the pylorus.[^[179]] This case shows that the present variety of perforation may take place without the preliminary organic disease being indicated by any symptom. The circumstances under which it commenced are peculiarly important in relation to the medical jurisprudence of poisoning. Another case which has been lately described with great exactness by M. Duparcque, was preceded only by very trivial dyspeptic symptoms. Here the whole mischief arose from a small ulcer eight lines long and five in breadth on the inside of the stomach, and not more than a line and a half in diameter at the perforation through the peritonæum.[^[180]] Several excellent examples of the same disease have been related by Dr. Abercrombie.[^[181]] In one of these the ulcer in the centre of which the perforation had been formed, was not bigger than a shilling, and the rest of the stomach quite healthy. A very instructive case of a similar nature, but of unusual duration, has been related by Mr. Alfred Taylor. A young woman, after suffering for some time from nausea and constant craving for food, but inability to indulge it, and occasionally from pain in the stomach, was attacked suddenly with the usual symptoms of perforation, and died forty-two hours afterwards. The villous coat of the stomach, though generally healthy, presented at the lesser curvature several small elevated points, and in the middle of two of these a sharply-defined ulcer, one affecting the mucous coat only, while the other, which was half an inch in diameter where it affected the mucous coat, perforated the muscular and peritonæal coats by a hole no bigger than a crow-quill.[^[182]] A case still more remarkable has been also related by the same author, where the circumstances naturally gave rise to a strong suspicion of poisoning. A young female in a noble family, subject to slight dyspepsia, was suddenly attacked, three hours after a meal, with violent vomiting and pain in the belly. Collapse soon ensued, and in fifteen hours she died, under so strong suspicions of poisoning that various antidotes were administered. This suspicion was in some measure borne out by proofs of an intrigue having been carried on between her and a male person in the house, and by the discovery after death of the signs of recent sexual intercourse. On examining the cavity of the abdomen, however, there was found, at the upper and back part of the stomach near the pylorus, an oval perforation, half an inch wide, surrounded by a firm, smooth, almost cartilaginous margin, without any inflammation near it. Mr. Taylor properly points out, that the sudden occurrence of such violent symptoms so long after a meal is incompatible with the action of any poison which could cause perforation in fifteen hours; and that the characters of the perforation were those of a natural disease long latent. He could not detect a trace of any poison in the stomach.[^[183]]—In some cases, as in that of M. Duparcque, the pain at the moment the perforation is completed is not at first violent, because the close proximity of some adjoining organ, such as the liver, prevents the contents of the stomach from escaping for a time, so that inflammation of the peritonæum is but gradually developed.

The third variety of spontaneous perforation is of a much more singular kind. It is produced not by ordinary ulceration, but by a jelly-like softening of the coats. The gelatinization sometimes extends over a great extent of surface, affecting chiefly the villous coat, so that the aperture through the other membranes is surrounded by extensive pulpiness of the internal membrane. It is seldom accompanied by vascularity. Its symptoms are exceedingly obscure. In adults there is very rarely any symptom at all till the perforation is complete;[^[184]] in children, as appears from a paper by Dr. J. Gairdner of this city, and another by Dr. Pitschaft, a German author,[^[185]] the early symptoms indicate an obscure chronic gastritis. The nature of this singular disease will be discussed in the section on the morbid appearances. At present it may merely be observed, that the injury caused to the coats of the stomach seems to be precisely the same with the gelatinization, which is sometimes found after death in persons who had no symptoms of an affection of the stomach, and which is ascribed by John Hunter,[^[186]] and most British pathologists, to the solvent action of the gastric juice in the dead body. This disease is well described by Laisné in his thesis formerly quoted. The following is a good example: a young lady, previously in good health, was awakened at three one morning with excruciating pain in the stomach, which nothing could alleviate. She expired seven hours after; and on dissection two holes were found in the back part of the stomach, surrounded with much softening of the villous coat.[^[187]] Another case will be mentioned in page [118].—The appearances produced by this disease have been mistaken for the effects of corrosive poisons.

12. The gullet may be perforated in a similar manner either with or without symptoms. Under the head of the morbid appearances ([119]) two instances will be mentioned in which there were no corresponding symptoms. In the following case symptoms did pre-exist. A man, six weeks after being bit by a dog, which was killed without its state of health having been ascertained, was attacked with a sense of strangling, impossibility of swallowing, delirium, excessive irritability, glairy vomiting; and he died within twenty-four hours. The gullet, a little above the diaphragm, was perforated by a hole two-thirds of an inch in diameter, with thin edges; and effusion had taken place into the posterior mediastinum.[^[188]]

13. Perforation of the alimentary canal by worms may here also be noticed shortly as a disease liable in careless hands to be confounded with irritant poisoning. This is far from being a common accident, and very rarely takes place during life. In most of the cases in which it has been witnessed the symptoms antecedent to death were those not of irritant, but of narcotic poisoning, and were then owing simply to the great accumulation of worms in the alimentary canal. On this subject the reader is referred to the article Epilepsy in the introductory remarks on the effects of the narcotic class of poisons. But at times the symptoms have been like those of irritant poisoning. Thus the following is a case of perforation by worms during life giving rise to all the phenomena and symptoms of peritonæal inflammation. A soldier at Mauritius was seized with slight general fever and severe pain, at first in the pit of the stomach, and afterwards over the whole belly, which on the third day began to enlarge. A tendency to suppression of urine and costiveness ensued, then bilious vomiting; and he died on the fourth day, the belly having continued to increase to the end. On dissection, several quarts of muddy fluid were found in the sac of the peritonæum, the viscera were agglutinated by lymph, a round worm was discovered among the intestines between the navel and pubes, and the ileum was perforated six inches from the colon by a hole corresponding in size with the worm.[^[189]]—A singular case, not however fatal, but which confirms the fact, that worms may make their way through the intestines and other textures during life, is mentioned in Rust’s journal. A woman after a tedious illness first vomited several lumbrici, and was then seized with a painful swelling in the left side, which in the process of time suppurated, and discharged along with the purulent matter three other worms of the same species.[^[190]] Another instance of the same kind, where the perforation of the gut succeeded strangulated hernia, and was followed by the discharge of two lumbrici and ultimate recovery, is detailed in the Revue Médicale.[^[191]]

Symptoms like those of narcotico-acrid poisoning may be caused by worms without perforation. A girl, eight years old and in excellent health, was suddenly seized with violent colic pains, vomiting, bloody stools, tenderness and swelling of the belly, followed by convulsions and coma, and proving fatal in seven hours. No other explanation of the case could be discovered on dissection except the presence of several hundred ascarides in the intestines and thirteen in the stomach.[^[192]]

14. The next diseases to be mentioned are melæna and hæmatemesis, or purging and vomiting of pure or of altered blood.

It is hardly possible to mistake them for poisoning, as the pain which accompanies them is seldom acute, and the discharge of blood generally profuse.

15. The last are colic, iliac passion, and obstructed intestine. As the symptoms of some poisons are the same with those of colic, it is of course sometimes impossible to distinguish the natural disease from the effects of poison by attending to the abdominal symptoms only. But the distinction in severe cases of poisoning may almost always be drawn from collateral symptoms and extraneous circumstances.—The iliac passion is distinguished by a complete reversion of the vermicular motion of the intestines in consequence of which the fæces are often discharged by vomiting. I am not aware that stercoraceous vomiting is ever caused by poisoning.—A case has been recorded in Corvisart’s journal, in which iliac passion, originating in obstruction of the ileum by hardened fæces, and proving fatal in twenty-six hours, gave rise to a judicial inquiry into the possibility of poisoning.[^[193]] Another instance, that led to a strong suspicion of poisoning, has been lately published by M. Rostan, in which there was continued vomiting and pain of abdomen, proving fatal in two days, and arising from the small intestines being obstructed by an adventitious band.[^[194]] In this case the first inspectors failed to observe the true cause of the symptoms; but Rostan and Orfila, who were appointed to examine the body a second time, discovered the constriction, and were unable to find any poison in the stomach by analysis. Stercoraceous vomiting occurred during life; which might have been held sufficient to settle the real nature of the case.—Obstruction of the intestines arising from twisting of the gut, intussusception, foreign bodies, or strangulated hernia, is easily known by the seat where the pain begins, by the obstinate constipation, and also by the excessive enlargement of the belly,—which last, however, is rather an equivocal symptom.

The preceding observations will enable the medical jurist to determine, how far a diagnosis may be drawn from the symptoms between poisoning with the irritant and the diseases which resemble it. It will be remarked that the most embarrassing disease, on account of its frequency, and peculiar symptoms, is cholera. Cholera, however, may be recognised in some instances even considered in regard to the irritants as a class; and we shall presently find that it may be distinguished still better from the effects of some individual poisons.

Section II.—Of the Morbid Appearances caused by Irritant Poisons, compared with those of certain natural diseases.

The next subject for consideration is the morbid appearances produced by the irritants as a class, together with those of a similar nature, which arise from natural causes.

The powerful irritants, which are not corrosives, produce simply the appearances characteristic of inflammation of the alimentary canal in its various stages,—in the mouth, throat, and gullet vascularity, and also, if the case has lasted long enough, ulceration;—in the stomach, vascularity, extravasation of blood under and in the substance of the villous coat and likewise into the cavity of the organ, abundant secretion of tough mucus, deposition of coagulable lymph in a fine network, ulceration of the membranes, occasionally perforation, preternatural softness of the whole or of part of the villous coat, and on the other hand sometimes uncommon hardness and shrivelling of that coat; in the intestines vascularity, extravasation, and ulceration.—Sometimes several of these appearances are to be seen in the whole alimentary canal at once. In poisoning with arsenic or corrosive sublimate it is no unusual thing to meet with redness or ulceration of the throat, great disease in the stomach, vascularity of the small intestines, ulcers in the great intestines, and excoriation of the anus.—When the poison is an active corrosive much more extensive ravages are sometimes caused, particularly in the stomach. After poisoning by the mineral acids, for example, the whole mucous membrane of the stomach is at times found wanting; nay, large patches of the whole coats may be wanting, and the deficiency supplied by the adhesion of the margin of the aperture to the adjoining viscera, and the conversion of the outer membrane of these viscera into an inner membrane for the stomach.

Of the appearances here briefly enumerated the particulars will be related partly under what is now to be said of the appearances arising from natural causes, which are liable to be confounded with the effects of poisons, partly under the head of individual poisons.

Of redness of the stomach and intestines from natural causes, and its distinction from the redness caused by poisons.

Simple redness of the alimentary mucous membrane in all its forms, whether of mere vascularity, or actual extravasation, not only does not distinguish poisoning from inflammatory disorders of natural origin, but will even seldom distinguish the effects of poison from those of processes that occur independently of disease, and subsequent to death. On the subject of real inflammation, as distinguished from redness originating after death, or pseudo-morbid redness, as it is commonly termed,—a subject of great consequence to the medical jurist,—the reader may consult with advantage a paper by Dr. Yelloly,[^[195]] an essay by MM. Rigot and Trousseau,[^[196]] or that of M. Billard.[^[197]] The former authors proved by experiment, that various kinds of pseudo-morbid redness may be formed, which cannot be distinguished from the parallel varieties caused by inflammation; that these appearances are formed after death, and not till three, five, or eight hours after it; that they are to be found chiefly in the most depending turns of intestines, and in the most depending parts of each turn, or of the stomach; and that after they have been formed, they may be made to shift their place, and appear where the membrane was previously healthy, by simply altering the position of the gut. M. Billard, on the other hand, has laid down their characters, and made a minute arrangement of the several kinds. He has divided them into ramiform, capilliform, punctated, striated, laminated, and diffuse redness,—terms which need hardly be explained. I must be content with merely referring to these sources of information for a particular account of the appearances in question. But it may be right at the same time to quote an instance of the most aggravated form of pseudo-morbid redness, in order to convince the reader that all forms may equally arise from the same causes. Among other example, then, which have been related of laminated redness, or redness in patches from extravasation, M. Billard mentions the case of a man who hanged himself, and in whose body was found, on the mucous membrane of the small intestine where it lay in the right flank, “a large, amaranth-red patch, six finger-breadths wide, covered with bloody exudation, and not removable by washing:” and in the lower pelvis there was a similar patch of even larger dimensions.[^[198]]

Although morbid and pseudo-morbid redness of the inner coat of the alimentary canal cannot be distinguished from one another by any intrinsic character, M. Billard thinks this may be done by attending to collateral circumstances. According to his researches, redness is to be accounted inflammatory only when it occurs in parts not depending in position, or is not limited to such parts: when the mesenteric veins supplying the parts are not distended, nor the great abdominal veins obstructed at the time of death; when the reddened membrane is covered with much mucus, particularly if thick, tenacious, and adhering; when the mucous membrane itself is opaque, so that when dissected off and stretched over the finger, the finger is not visible; when the cellular tissue which connects that membrane with the subjacent coat is brittle, so that the former is easily scratched off with the nail.

Some observations may be here also made on another appearance, allied to the present group, but which there is strong reason to believe always indicates some violent irritation at least, if not even irritation from poison only, in the organ where it is found. It is an effusion under the villous coat of the stomach, and incorporation with its substance, of dark brownish-black, or as it were charred, blood; which is thus altered either by the chemical action of the poison, or by a vital process. In many cases of poisoning with the mineral acids, oxalic acid, arsenic, corrosive sublimate, and the like, there are found on the villous coat of the stomach little knots and larger irregular patches and streaks, not of a reddish-brown, reddish-black, or violaceous hue, like pseudo-morbid redness, but dark-grayish-black, or brownish-black, like the colour of coal or melanosis,—accompanied too with elevation of the membrane, frequently with abrasion on the middle of the patches, and surrounded by vascularity. This conjunction of appearances I have never seen in the stomach, unless it had been violently irritated; and several experienced pathologists of my acquaintance agree with me in this statement. It bears a pretty close resemblance to melanosis of the stomach;[^[199]] but is distinguished by melanotic blackness being arranged in regular abruptly-defined spots, and still better by melanosis not being preceded by symptoms of irritation in the stomach.

Referring to what was already said under the head of the symptoms of gastritis [p. [102]], I must again express my doubts whether the appearances now described ever arise in this country from natural disease. In the intestines they are sufficiently familiar to the physician, as arising from idiopathic enteritis, and from dysentery. But in the stomach their existence as the effect of natural disease is very doubtful.

Another kind of coloration of the inner membrane of the stomach, which may be shortly alluded to, because it has actually been mistaken for the effect of irritation from poison, although by no means like it,—is staining of the membrane with a reddish, brownish, yellowish, or greenish tint, observed in bodies that have been kept some time, and produced by the proximity of the liver, spleen, or colon if it contains fæces. No unprejudiced and skilful inspector could possibly mistake this appearance for inflammation. But under the impulse of prejudice it has been considered such, and imputed to poison. On the occurrence of such stains an attempt was made by the French to ascribe to poison the death of the republican general Hoche. He died rather suddenly on his way from Frankfort to join his troops; and as poisoning was suspected, the body was opened in the presence of three French army-surgeons, and a French and two German physicians. The only appearance of note in the alimentary canal was two darkish spots on the villous coat of the stomach. The surgeons drew up a report which imputed his death to poison; but the physicians refused to sign it; and other medical people who were subsequently added to the commission decided with the latter.[^[200]] The surgeons probably would not have been so hasty, if they had not known that the result of their complaisance would have been the levying of a heavy fine on the inhabitants.

The last kind of discoloration of the inner coat which requires mention is dyeing from the presence of coloured fluids in the contents. A remarkable instance has been recorded where redness of this nature was mistaken for inflammation, and the death of the individual in consequence ascribed at first to poison. A person long in delicate health died suddenly after taking a laxative draught; and the stomach, as well as the gullet, being found on dissection red and livid in various places, it was hastily inferred by his medical attendants, that these appearances were the effect of poison, and that the apothecary had committed some fatal error in compounding the draught. But another physician, who was acquainted with the deceased, although he did not attend him professionally, strongly suspected he had died a natural death; and happening to know he was in the practice of taking a strong infusion of corn-poppy, inferred that the supposed signs of inflammation were merely stains arising from the habitual use of this substance. Accordingly, on making the experiment, he found that in dogs to which a similar infusion was given, appearances were produced identically the same.[^[201]]

Of the effusion of mucus and lymph from natural causes.—The abundant secretion of tough mucus in the stomach is a sign of that organ having been irritated. But the effusion of lymph is more characteristic. This may be produced by natural inflammation as well as by irritating poisons. As arising from either cause, however, it is rare; and certainly by no means so common as would be supposed from what is said in systematic works; for tough mucus has been often mistaken for it. Reticulated lymph adhering to the villous coat, and accompanied with corresponding reticulated redness of that coat, such as I have seen in animals poisoned with arsenic or oxalic acid, is an unequivocal sign of inflammation.

Of idiopathic ulcers and perforation of the stomach and intestines, and their distinction from those caused by poison.—Both ulceration and perforation may be produced by natural disease. In the ulceration produced by poisons there is generally speaking nothing to distinguish it from natural ulcers; but that caused by some poisons, such as iodine, is said to differ by the surrounding coloration of the membrane; and when the ulcer is caused by a sparingly soluble poison in a state of powder, such as arsenic, the cavity of the ulcer is sometimes filled with the powder. Perforation is a rare effect of the simple irritant poisons; but it is often caused by corrosives. It is imitated by two of the varieties of perforation from natural disease.

The form of natural perforation caused by a common ulcer is precisely the same as that caused by the simple irritants, and is incapable of being distinguished, except when it is attended with scirrhus.

By far the most remarkable variety, however, of spontaneous perforation is that which takes place, without proper inflammatory action, from simple gelatinizing of the coats. It is very apt to be mistaken, and in a celebrated trial, which will be immediately noticed, was actually mistaken for the effect of corrosive poison.

It may be situated on any part of the stomach, but is oftenest seen on the posterior surface. It is sometimes small, more often as big as a half-crown, frequently of the size of the palm, and occasionally so great as to involve an entire half of the stomach. Sometimes there is more than one aperture. The margin is of all shapes, commonly fringed, and almost always formed of the peritoneum, the other coats being more extensively dissolved. In one instance, however, the peritonæal surface was on the contrary the most extensively destroyed;[^[202]] and in a case which occurred in the infirmary here, and was pointed out to me by the late Dr. W. Cullen, the peritonæum alone was extensively softened, and partly dissolved, so as to lay the muscular coat bare on its outer surface. The gelatinization therefore sometimes, though very rarely, begins on the outside of the stomach. Internally the whole is surrounded by pulpiness of the mucous coat, generally white, occasionally bluish or blackish, never granulated like an ulcer, very rarely vascular; and when vascular, the blood may be squeezed out of the loaded and open vessels. The organs in contact with the hole are also frequently softened. Thus an excavation is sometimes found in the liver or spleen; or the diaphragm is pierced through and through. The margins of the latter holes are without any sign of vascular action, but are generally besmeared with a dark pulpy mass, the remains of the softened tissue. The pulp never smells of gangrene; with which, indeed, this species of softening is wholly unconnected. The edge of the hole in the stomach never adheres to the adjoining organ; yet, even when the hole is very large, the contents of the stomach have not always made their escape. Often the dissolution of the coats is incomplete. John Hunter and others, indeed, have said that a stomach is rarely seen without more or less solution of the mucous coat.[^[203]] The best account of the appearances in this state is given by Jaeger of Stuttgardt.[^[204]]

The circumstances under which this extraordinary appearance occurs are singularly various. Professor Chaussier and the French pathologists conceive it to be always a morbid process constituting a peculiar disease; and doubtless cases have occurred in which death appears to have arisen from the stomach being perforated during life by gelatinization.[^[205]] But it has been found much more frequently, when death was clearly the consequence of a different disease, and when there did not exist during life a single sign of disorder in the stomach. Thus it has been found in women who died of convulsions after delivery,—in children who died convulsed or of hydrocephalus,—after death from suppuration of the brain, both natural and the result of violence,—from coma following an old ulcer of the back, which communicated with the spinal canal,—from diseased mesenteric glands,—from phthisis,—from nervous fever,—and after sudden death from fracture of the skull or hanging:[^[206]] and in all of these circumstances it has occurred without any previous symptom referrible to a disorder in the stomach.

The opinions of pathologists are divided as to its nature. The French conceive it arises from a morbid corrosive action, which, however, may extend after death, in consequence of the fluids acquiring a solvent power. Hunter ascribed it entirely to the solvent power of the gastric juice after death. There are difficulties in the way of both doctrines. A full examination of the whole inquiry, which is one of much interest and considerable complexity, would be misplaced in this work; but some remarks are called for, by reason of the important medico-legal relations of the subject, and the uncertainty in which it is at present involved.

In the first place, then, it appears difficult, if not impossible, to comprehend how a vital erosive action can account for the perforations observed after death from diseases wholly unconnected with the stomach, and unattended during life by any symptom of disorder in that organ. For, not to dwell on other less weighty arguments,—on the one hand, there is during life no symptom of perforation, an accident which if deep stupor be not present at the same time is always attended with violent symptoms when it arises from any cause but gelatinization,—and on the other hand, there is frequently no escape of the contents of the stomach into the cavity of the abdomen, though the hole is of enormous size, and its edge not adherent to the adjoining organs.—All such perforations, however, are perfectly well accounted for, on the other theory, by what is now known of the properties of the gastric juice. This will appear from the following exposition.

The power of the gastric juice to dissolve the stomach and other soft animal textures was long thought to be fully proved by the well-known researches of Spallanzani,[^[207]] Stevens,[^[208]] and Gosse.[^[209]] In later times doubts were entertained on the subject in consequence of negative results having been obtained by other experimentalists, more especially by Montégre.[^[210]] But these apparently discrepant facts and opinions have been reconciled by the ulterior experiments of Tiedemann and Gmelin on digestion;[^[211]] who found that the nature and quality of the fluid secreted by the stomach vary much in different circumstances,—that, when its villous coat is not subjected to some stimulus, the fluid which lines it is not acid, and does not possess any particular solvent action,—but that when the membrane is stimulated by the presence of food or other sources of excitement, the quality of the secretion is materially changed, for it becomes strongly acid and is capable of dissolving alimentary substances both in and out of the body. And still more lately the solvent power of the proper gastric juice over the stomach, and its capability of producing perforation in animals after death, have been established in the most satisfactory manner by Dr. Carswell,[^[212]] who has shown by a series of incontrovertible facts,—that in the rabbit when killed during the digestion of a meal, and left for some hours afterwards in particular positions, all the phenomena of spontaneous gelatinized perforations observed at times in man, may be easily produced at will,—that acidity of the gastric juice is an invariable circumstance when such perforations are remarked,—and that the appearances in question as they occur in the rabbit are the result of chemical action alone, and occur only after death. Thus, then, the physiological experiments of Tiedemann and Gmelin, together with the investigations of Carswell, not merely establish positively the fact, that the stomach may be perforated after death by the gastric juice, but likewise account clearly for the negative results obtained by other experimentalists. For example, passing over earlier experiments, they explain sufficiently the negative results obtained by Dr. Pommer of Heilbronn,[^[213]] an experimentalist of some reputation in Germany; for, falling into the error of some of the less recent experimentalists on this subject, he made his observations on animals killed slowly by starving,—in which circumstance there is no proper gastric juice in the stomach, and consequently no solvent action can exist.

These statements relative to the causes and phenomena of gelatinized perforation in the stomach supply the strongest possible presumption which analogy can furnish, that a great proportion of spontaneous gelatinized perforations in the human subject are owing to the action of the gastric juice after death. And this presumption is increased to something not far removed from demonstration by the circumstance, that in man the process of softening has actually been traced extending in the dead body. This interesting fact was first noticed by Mr. Allan Burns.[^[214]] In the body of a girl who died of diseased mesenteric glands he found an aperture in the fore part of the stomach with the usual pulpy margin, and the liver in contact with the hole uninjured. In two days more the liver opposite the hole had become pulpy, and its peritonæal coat quite dissolved; and the back part of the stomach opposite the hole was also dissolved, so that only its peritonæal coat remained. Dr. Sharpey has communicated to me a similar observation. On finding in the body of a child the stomach perforated and gelatinized, but the adjoining organs uninjured, he sewed up the body, to show the appearances to some of his friends next day. By that time the peritonæal surfaces of the spleen and left kidney were found much softened and pulpy where they lay in contact with the hole in the stomach. I have since met with a similar occurrence where the perforation affected the duodenum (p. [120]).

It must be admitted, then, that the action of the gastric juice after death is quite sufficient to account for the greater number of gelatiniform perforations in the human stomach.

But in the second place, it seems scarcely possible to explain every perforation of the kind in this way. The solvent action of the gastric juice for example, affords no explanation of a singular case related by M. Récamier,[^[215]] where, after death in the secondary stage of small-pox, the stomach was transparent and brittle, and perforated in the splenic region by a gelatinized hole large enough to admit the fist,—although the fluid in the stomach was subsequently found incapable of dissolving another stomach, and almost destitute of free acid. And still less will the solvent action of the gastric juice account for such cases as those of Laisné and Gastellier, quoted in pp. [107]–8, or the French medico-legal case to be mentioned in p. [118],—where death is preceded by a short illness, indicating a violent disorder of the stomach, and sometimes even characterized by all the marked symptoms of perforation. In the last description of cases, which are comparatively very rare, it seems necessary to admit that the gelatinization takes place during life; unless, indeed, it be supposed that the stomach is first perforated during life by ordinary ulcerative absorption, and then gelatinized after death, in consequence of the irritation existing before death having given rise to an unusual secretion of gastric juice.

Passing now to the differences between these gelatinized perforations, and the perforations caused by corrosive poisons, it may in the first instance be observed, that the margin of a corroded aperture is sometimes of a peculiar colour,—for example, yellow with nitric acid, brown with sulphuric acid or the alkalis, orange with iodine. But a much better, perhaps indeed an infallible criterion, and one of universal application, is the following. Either the person dies very soon after the poison is introduced, in which case vital action may not be excited in the stomach: or he lives long enough for the ordinary consequences of violent irritation to ensue. In the former case, as a large quantity of poison must have been taken, and much vomiting cannot have occurred, part of the poison will be found in the stomach: In the latter case, the poison may have been all ejected; but in consequence of the longer duration of life, deep vascularity, or black extravasation must be produced round the hole, and sometimes too in other parts of the stomach; changes which will at once distinguish the appearance from a gelatinized aperture. There is no doubt that the stomach may be perforated by the strong corrosives, and yet hardly any of the poison be found in the stomach after death. Thus in a case related by Mertzdorff of poisoning with sulphuric acid, where life was prolonged for twelve hours, he could detect by minute analysis only 4½ grains of the acid in the contents and tissue of the stomach. But then the hole was surrounded by signs of vital reaction, and so was the spleen upon which the aperture opened.[^[216]] Judging from what I have often seen in animals killed with oxalic acid, which is the most rapidly fatal of all corrosives, so that little time is allowed for vital action, and also several times in persons who had died quickly from the action of sulphuric acid, I believe no poison can dissolve the stomach, without such unequivocal signs of violent irritation of the undissolved parts of the villous coat, as will secure an attentive observer from the mistake of confounding with these appearances the effects of spontaneous erosion. Spontaneous erosion is very generally united with unusual whiteness of the stomach, and there is never any material vascularity.

Resting on the description now given of the spontaneous and poisonous varieties of corrosion, it is an easy matter to decide a controversy, which at the time it occurred made a great deal of noise, and upon which the opinions of toxicologists have been unnecessarily divided. It is the question regarding death by poison which occurred in the trial of Mr. Angus at Liverpool in 1808 for the murder of his housekeeper Miss Burns. The poison suspected was corrosive sublimate. The symptoms were those of irritation in the alimentary canal,—vomiting, purging, and pain. In the dead body there was not any particular redness either of the intestines or of the stomach. But on the fore part of the stomach an aperture was found between the size of a crown piece and the palm of the hand; it had a ragged, pulpy margin; and the dissolution of the inner coat extended two inches from it all round the hole. No mention is made of adhesion or coloration of the margin. This description, it will be remarked, answers exactly that given above of spontaneous gelatinized perforation; and the absence of the signs of vital action around the hole and in the rest of the stomach is incompatible with the effects of a strong corrosive poison, unless death had occurred very soon after it was swallowed. This, however, was out of the question; for then the poison would have been found in the stomach,—which it was not.[^[217]]

The case of Angus is not the only instance in recent times of spontaneous perforation having given rise to an opinion by medical men in favour of poisoning, and consequently to a criminal trial. Six years afterwards a similar incident occurred in France. A young woman near Montargis having died of a short illness, and a large erosion having been found in the stomach after death, six practitioners, on a view of the parts, and without referring to the antecedent symptoms or attempting an analysis of the contents of the stomach, declared that she died of the effects of some corrosive poison. The husband and mother-in-law, against whom there does not appear to have been a shadow of general evidence, were therefore imprisoned and subsequently tried for their lives. Luckily, however, an intelligent physician of the town saw the error of the reporters, and after vainly endeavouring to persuade them to revise their opinion, was the means of the case being remitted to the medical faculty of Paris. That distinguished body, with Professor Chaussier at its head, gave a unanimous and decided opinion, not only that there was not any proof of poisoning, but likewise that the woman could have died of nothing else than spontaneous perforation. The leading features of the medical evidence will at once show how indefensible the conduct and opinion of the original reporters were. The last meal taken by the woman before she became ill, and the only one at which poison could have been administered by the prisoners, was her supper; her illness did not begin till past six next morning; the symptoms were mortal coldness, fainting, general pains, headache, pain in the stomach, purging and colic, without vomiting, and she died after twenty-four hours’ illness; the morbid appearances were general redness of the stomach, softening and pulpy destruction of a third part of its posterior parietes, and nevertheless the presence in the stomach of a pint and a half of fluid matter, containing evidently the remains of soup taken by the woman after she felt unwell. On the decision of the Parisian faculty the prisoners were discharged; and the original reporters were deservedly handled with great severity in several publications that appeared not long after.[^[218]]

Of perforations of the Gullet and Intestines from natural causes, and their distinctions from those produced by poisons.—The intestines, and sometimes even the gullet, may be perforated by the same erosive or solvent process as the stomach. Thus Mr. Allan Burns observes, that in four plump children, whose previous history he could not learn, he found every part of the alimentary canal, from the termination of the gullet down to the beginning of the rectum, reduced to a gluey, transparent pulp, like thick starch. The bodies were quite free from putrefaction; but the abdomen exhaled a very sour smell when opened. No other organic derangement could be detected.[^[219]] The particulars of a similar case, with an account of the symptoms, have been lately published by Mr. Smith, a London surgeon. In the body of a child who died of protracted diarrhœa subsequent to weaning, the whole intestines, from the duodenum to the sigmoid flexure of the colon, were found fourteen hours after death gelatinous, semitransparent, and so soft and brittle that they could not bear their own weight, but tore when lifted between the fingers. The stomach and rectum were healthy.[^[220]] I lately met with the following instance, where the erosion clearly took place after death. In the body of a girl who died within twelve hours of poisoning with red-precipitate, the stomach and duodenum were found much inflamed, but quite entire and firm three days after death. Eighteen days afterwards, when I had an opportunity of examining these organs, their textures remained firm everywhere, except a few inches below the pylorus, where I found two apertures in the duodenum, each as big as a crown, and surrounded by extensive jelly-like softening.

The following case from Laisné’s treatise shows that the gullet may be also dissolved in the same way. A woman three days after delivery was attacked with puerperal peritonitis, and died in four days. In the belly were found the usual morbid appearances of peritonitis: but in addition there was in the lower part of the gullet a large oval aperture two inches long, which penetrated through the posterior mediastinum into the lungs.[^[221]] Another singular instance of the same kind has already been mentioned under the head of the symptoms (see p. [107]). Another has been described by Dr. Marshall Hall. In a child who died of bronchitis, an opening was found in the gullet about the size of a pea, so that the canal of the gullet communicated with the sac of the pleura; and several veins appeared also to have been opened.[^[222]] The stomach was likewise perforated.

It is not difficult to draw the distinction between these perforations and the effects of poison. The throat and gullet may be partially disorganized or corroded by the strong corrosives; but they are very rarely penetrated, since the greater part of the poison must pass into the stomach or be rejected by vomiting. Destruction of the mucous coat is a common consequence, and stricture occasionally follows; but I have hitherto met with only one instance among the innumerable published cases of poisoning with the mineral acids, alkalis, and other corrosives, where the gullet was perforated. In that case the perforation was the result of slow ulceration from poisoning with sulphuric acid, where life was prolonged for two months.[^[223]] Perforation from simple corrosion never occurs. The intestines are never perforated by chemical corrosion from within, for either the poison is in a great measure expelled from the stomach by vomiting, or the pylorus contracts and prevents the passage of every poison that is sufficiently concentrated to corrode. Both the small and great intestines might be corroded from without, in consequence of the poison escaping through a hole in the stomach. I am not acquainted, however, with any case of the kind where, intestinal perforation has occurred.

When the intestines are pierced by true ulceration, it is impossible to tell whether it arose from natural disease or an irritant poison.

The mode of forming a diagnosis between the symptoms and appearances of irritant poisoning and those of natural disease being thus explained, the different species of poisons which have been arranged in the class of irritants will now be considered in their order.

The irritant class of poisons may be divided into five orders: the acids and their bases; the alkalies and their salts; the metallic compounds; the vegetable and animal irritants; the mechanical irritants. In a short appendix some substances will be mentioned which are not usually considered poisonous, but are capable of causing violent symptoms when taken in large doses.

The greater number of poisons included in the first order have a very powerful local action. Most of them possess true corrosive properties when they are sufficiently concentrated. Most of them likewise act remotely. One of them, oxalic acid, is evidently not so much an irritant as a narcotico-acrid; but since its most frequent action as seen in man is irritation, it seems inexpedient to break the natural arrangement for the sake of logical accuracy. This is far from being the only instance where the toxicologist is compelled to violate the principles of philosophical classification.

In the present Order are included four of the mineral acids, the sulphuric, nitric, muriatic and phosphoric, with their bases, phosphorus, sulphur, and chlorine: To these may be added iodine and bromine, with their compounds, and also oxalic and acetic acid, two of the vegetable acids.

CHAPTER III.
OF POISONING WITH THE MINERAL ACIDS.

Of the mineral acids, the most important, because the most common, are sulphuric, hydrochloric, and nitric acids. They are remarkably similar in their effects on the animal economy. Phosphoric acid is of much less consequence, and will be noticed cursorily.

Sulphuric acid (vitriolic acid, vitriol—oil of vitriol), hydrochloric acid (muriatic acid,—spirit of salt) and nitric acid (aqua-fortis), have been long known to be possessed of very energetic properties; and consequently cases of poisoning with them have often been observed. The instances of the kind hitherto published have been chiefly the result of suicide; a considerable number have originated in accident; and, however extraordinary it may appear, a few have been cases of murder. Tartra, in an excellent memoir on the subject of poisoning with nitric acid, quotes an instance of a woman having been poisoned while in a state of intoxication by that acid being mixed with wine and poured down her throat.[^[224]] Valentini has related the case of a woman who was killed by frequent doses of sulphuric acid given under the pretence of administering medicines.[^[225]] In 1829 an hospital servant was condemned at Strasbourg for trying to murder his wife in like manner, by first making her ill with tartar-emetic and then giving her sulphuric acid in syrup, under the pretence of curing her.[^[226]] At the Aberdeen autumn circuit in 1830 a woman Humphrey was convicted of murdering her husband by pouring the same acid down his throat while he lay asleep with his mouth open.[^[227]] On the whole, considering the powerful taste and excessively acrid properties of these poisons, it is probable that they will seldom be resorted to for the purpose of making away with another person, who is an adult, and in a state of consciousness. Of late, however, there have been several instances in our country of murder committed on infants in this barbarous manner. A woman Malcolm was executed here in 1808 for murdering her own child, an infant of eighteen months, by pouring sulphuric acid down its throat;[^[228]] another woman Clark was tried for the same crime at Exeter in 1822; a man was executed lately at Manchester for murdering in the same way his son, a child four years and a half old;[^[229]] and the particulars of an interesting trial will be presently noticed, that of Overfield, who was executed at Shrewsbury in 1824, for poisoning his child in the like manner.[^[230]]

In a medico-legal point of view, the mineral acids are interesting on another account. Of late a new crime has arisen in Britain, the disfiguring of the countenance by squirting oil of vitriol on it. It originated in Glasgow, during the quarrels in 1820, between masters and workmen regarding the rate of wages,[^[231]] and became at last so frequent, that the Lord Advocate, in applying for an act of Parliament to extend the English Stabbing and Maiming act to Scotland, added a clause which renders the offence now alluded to capital. In 1828 a woman Macmillan was tried here and condemned under that act.[^[232]] The crime afterwards became common in England. Three cases were noticed in the newspapers as having occurred in London, in November, 1828; and two others near Manchester in the spring of 1829. It is now much less frequent.

The mineral acids are also very interesting on scientific grounds. They afford the purest examples of true corrosive poisons, their poisonous effects depending entirely on the organic injury they occasion in the textures to which they are applied. It is of use to set out, in investigating the effects of poisons, by determining the phenomena presented under such circumstances. When made aware of the rapidity with which other irritating poisons prove fatal, and the slight signs they commonly leave of their operation, one cannot fail to be struck with discovering what the animal frame will sometimes endure from these the most violent of all irritants, and nevertheless recover.

In laying down the mode of determining by chemical evidence a case of supposed poisoning with any of the three mineral acids mentioned above, it will be unnecessary to notice any of their chemical properties, except those from which their medico-legal tests are derived.

The only common properties that require notice are, their power of reddening the vegetable blue colours, for showing which litmus-paper is commonly used, and is most convenient: and their power of staining and corroding all articles of dress, especially such as are made of wool, hair, and leather. This last property is specified, though a familiar one, because it always forms important evidence in criminal cases. In order to give precision to such evidence, it is necessary to remember, that if the article of dress is a coloured one, it is generally rendered red by the mineral acids; but that the vegetable acids also will redden most articles of dress, although they do not corrode them.

I.—Of Poisoning with Sulphuric Acid.

Sulphuric acid is extensively employed in very many trades, is used even for some domestic purposes, and is consequently familiar to every one. Hence it is the mineral acid which has been most commonly used as a poison, especially for committing suicide. Of 35 cases of poisoning with the mineral acids which occurred in England in the years 1837 and 1838, 32 were caused by this acid (p. [90]).

Section I.—Of the Tests for Sulphuric Acid.

Sulphuric acid is known as a poison chiefly in the form of the concentrated commercial acid. But a few cases of poisoning have also been produced by blue-liquor or the solution of indigo in strong sulphuric acid; and one instance[^[233]] has been recorded of poisoning with the aromatic sulphuric acid of the Pharmacopœias, which is an infusion of aromatics in a mixture of sulphuric acid, ether and alcohol. In the following remarks on its tests, it will be sufficient to consider it first in the concentrated form,—secondly, in a state of simple dilution,—and thirdly, when mixed with various impurities, more especially with vegetable and animal matter. The acid solution of indigo may be known by the tests for the concentrated acid, and its blue colour, removable by a solution of chlorine; and the aromatic sulphuric acid may be distinguished by its odour and the tests for the diluted acid.

1. When concentrated it is oily-looking, colourless, or brownish from having acted on organic particles, without odour, much heavier than water, and capable of quickly corroding animal substances. If from these properties, and its effect in reddening litmus, its exact nature be not considered obvious, it may be heated with a few chips of copper; when sulphurous acid is disengaged and may be readily recognised by its odour.

2. When diluted, it may be distinguished from all ordinary acids by solution of nitrate of baryta occasioning a heavy white precipitate of sulphate of baryta, which is insoluble in nitric acid. Selenic and sulphurous acids, however, and also, as Mr. Alfred Taylor informs me he has lately found, the fluo-silicic acid, are similarly acted on in all respects. But selenic and fluo-silicic acids in all forms, and sulphurous acid in a state of solution, are so seldom met with, being known only in the laboratory of the scientific chemist, that they can scarcely be considered sources of fallacy. Sulphuric acid may at once be distinguished from sulphurous acid, by the latter possessing a peculiar pungent odour. From the two other acids it may be distinguished by collecting and drying the barytic precipitate, mixing this with charcoal, converting it into sulphuret of barium by heating it in a platinum spoon before the blowpipe, and then adding diluted muriatic acid to the sulphuret, so as to disengage sulphuretted hydrogen gas,—which again is easily known by its odour, or its property of blackening paper dipped in solution of acetate of lead. A much more important source of fallacy than these is the possible presence of a bisulphate in solution, or a neutral sulphate along with any other free acid; for these substances will present the same reactions with litmus and barytic salts as free sulphuric acid itself. Much has been published lately upon this point; but the difficulty has not yet been satisfactorily overcome. It may be got rid of indeed by proving, that no bisulphate or neutral sulphate is present. Their absence may be shown by no solid residuum being left on evaporating the suspected fluid, or at least no more than a mere haziness, owing to the sulphate of lead which commercial sulphuric acid always contains in small quantity. Or as Orfila suggests, we may establish their absence still better by concentrating the fluid, and finding that neither carbonate of soda, which would cause a precipitate with earthy or metallic bases, nor chloride of platinum, which would do so with potash or ammonia in combination, nor fluo-silicic acid, which precipitates soda salts, has any effect when applied to separate portions of the subject of inquiry. But suppose it appears in the course of these trials that one or more bases are actually present, how is it to be settled whether the sulphuric acid, indicated by litmus and a salt of baryta, is really free or not? To this question I must reply, that no method has yet been proposed, which is at once satisfactory and easily available. Mr. Alfred Taylor proposes to concentrate the fluid, and agitate it with alcohol, in the hope that the alcohol will remove sulphuric acid, and not a sulphate, from the water.[^[234]] But it removes sulphuric acid from a bisulphate even when dry, and still more when a little water is present. Orfila[^[235]] proposes, in the case of sulphuric acid in vinegar,—where there is both a vegetable acid and a neutral sulphate of lime,—to concentrate to a sixth, and agitate the residuum with four times its volume of sulphuric ether, in the expectation that this fluid will remove the free acid alone, and separate it from sulphates. But notwithstanding the authority of his name for the fact, pure ether will not remove sulphuric acid from a watery fluid; and etherized alcohol, which does remove it, takes it away also, like alcohol itself, from bisulphates. These results I have observed in some careful trials made along with Dr. Douglas Maclagan. I suspect, therefore, that where sulphates or bisulphates do exist, there is no absolutely satisfactory way of determining whether free sulphuric acid also co-exists, except by a quantitative analysis, for ascertaining whether the amount of acid and of bases corresponds with this supposition or not. And it is scarcely necessary to add, that so operose a method is scarcely applicable to ordinary medico-legal investigations.

3. It is seldom that the medical jurist is called on to search for sulphuric acid in either of the states already mentioned. Much more generally it has mingled with and acted on various organic substances. The circumstances in which it has usually to be sought for in the practice of medical jurisprudence are twofold,—on the one hand, in stains on clothes,—and on the other, in vomited matter, the contents of the stomach, or organic mixtures generally.

Process for analyzing stains on clothes.—When sulphuric acid is thrown upon your clothes, it produces a permanent red, reddish-brown, or yellowish stain, destroys the cloth entirely or renders it brittle, and in consequence of its strong attraction for water keeps the stain long in a moist state. In the course of the decomposition of the cloth a part of the acid is itself decomposed, sulphurous acid being disengaged. But it is an important medico-legal fact, that after a time the change either goes on very slowly, or is arrested altogether, possibly by the dilution of the acid with moisture from the atmosphere; and that consequently it may be discovered in a free state in stains after a much longer interval than would à priori be expected. In the case of Macmillan formerly alluded to, Dr. Turner and I, who were employed by the crown to examine the different injured articles of dress, found on a man’s hat, stock, shirt-collar and coat many discoloured and corroded spots, which were sour to the taste fourteen days after the crime was committed; in the subsequent case of Mrs. Humphrey I discovered six-tenths of a grain of free sulphuric acid in two small spots on a blanket seven weeks after the crime; and from an express experiment on the same blanket with two drops of acid of known strength, it appeared that only one-half of the acid disappeared in seven weeks. It may therefore be inferred, that, in every instance where stains have been produced by concentrated sulphuric acid on clothes, at least on woollen clothes, and no attempt has been made to remove the remaining acid by washing or neutralization, a sufficient quantity will be present even after several weeks to admit of being satisfactorily detected by chemical analysis.

The following are the steps of the process which appear to me the most delicate and equivocal. Cut away the stained spots; boil them for a minute or two in several successive small portions of distilled water; and filter if necessary. Next prove the acidity of the fluid by litmus, and likewise by the taste if the quantity of solution is large enough to allow of so coarse a test being used; and with a few drops ascertain the existence of sulphuric acid in one form or another by nitrate of baryta and nitric acid, as mentioned in the process for the pure diluted acid. If no precipitate appears, the search for sulphuric acid is at an end. But if a precipitate is produced, ascertain the absence of bisulphates and sulphates by proving the absence of bases, according to the method described in the process for the simple diluted acid. If, however, bases be found in material proportion to the acid, the analysis is subject to all the difficulties mentioned above in speaking of the detection of the diluted acid in similar circumstances.

Process for the contents of the stomach and other complex mixtures.—When sulphuric acid has been mixed with various mineral and organic substances, it may in no long time cease to exist in the free state. Part may be decomposed by organic matter in the way formerly mentioned. Or the whole may be neutralized at once by earthy or alkaline carbonates, administered purposely as antidotes. Or it may also be neutralized more slowly by the gradual development of ammonia in consequence of the decay of the animal matter co-existing in the mixture. Thus in a case mentioned by Mertzdorff of a child killed in twelve hours with sulphuric acid, the contents of the stomach did not redden litmus, but on the contrary had an ammoniacal odour; and they contained a considerable quantity of a soluble sulphate, probably the sulphate of ammonia.[^[236]] In like manner MM. Orfila and Lesueur found that when this acid was left some months in a mixture which contained putrefying azotized matter, it was gradually neutralized by ammonia.[^[237]] It appears from Orfila’s latest researches,[^[238]] that in most cases of acute poisoning with this substance some free acid will be found in the contents or tissues of the stomach, provided alkalis or earths were not given as antidotes, and the examination of the body be made before decay sets in.

The detection of sulphuric acid in complex organic mixtures, simple though it appears at first sight, is one of the most difficult problems in medico-legal chemistry. The difficulty arises from a variety of sources,—from the probable presence of neutral sulphates along with free hydrochloric, acetic, or some other acid,—the possible presence of a bisulphate,—the occasional neutralization of the sulphuric acid by antidotes given during life, or ammonia evolved during decay after death,—or its neutralization, together with the development of a different free acid, by its having displaced this acid from a salt existing in the mixture.

The subject was investigated in most of its relations in the last edition of the present work, and a process proposed which overcame some difficulties, but left others untouched. The inquiry has been since undertaken also by M. Devergie and Professor Orfila, but with most success in Germany by Dr. Simon.[^[239]] The result of all these researches is, that a satisfactory process for detecting sulphuric acid in organic mixtures still remains to be discovered. Meanwhile the most eligible method appears to me to be the following.

a. If the mixture be acid, add distilled water, if necessary, boil, filter, and test a few drops of the fluid with nitrate of baryta, followed by nitric acid. If there be no precipitate, the search for sulphuric acid is at an end. If a precipitate form, distil the fluid from a muriate of lime or oil bath, at a temperature not above 240°, till the residuum acquire a thick syrupy consistence; and preserve apart the last sixth of the distilled liquor. In this liquor test for hydrochloric acid by litmus-paper and nitrate of silver, and for acetic acid by litmus-paper, and the odour and taste of the liquid. If these acids be not in the distilled fluid, they are not in the residuum. In a portion of this residuum search for nitric acid, and in another portion for oxalic acid, by the processes for these poisons in complex mixtures. If all these acids be thus proved to be absent, it is most unlikely that the acidity of the mixture is owing to any other but sulphuric acid, especially in the case of the contents or textures of the stomach.

Dilute now what remains of the syrupy extract, and add nitrate of baryta with nitric acid. If a precipitate arise, there is a strong presumption that the acidity of the mixture was owing either to a bisulphate or to free sulphuric acid. And between these the question may be almost settled, first by the probability or improbability of a bisulphate having come in the way, and secondly, by the symptoms and morbid appearances. The result however cannot justify more than a presumptive opinion.—But if hydrochloric, acetic or nitric acid be indicated in the subject of analysis, or an acid sulphate, the whole process is vitiated, and it is scarcely possible to arrive at any trustworthy conclusion.

The difficulties adverted to above have been made the ground-work of various processes; which however seem to me all imperfect.—It has been proposed to divide the mixture into two equal parts, to precipitate one directly by a barytic salt, to do the same with the other after drying and incinerating it, to compare the weight of the precipitates, and to infer the presence of free sulphuric acid if the former is more than double the latter. Various objections however may be brought against this check, not the least serious being its difficulty in ordinary hands, whenever the precipitates are none of them considerable.—Simon proposes to exhaust the residuum of evaporation with absolute alcohol, in the hope that free sulphuric acid will alone be taken up;[^[240]] but he himself found that neutral sulphates are dissolved partially; and besides, alcohol removes sulphuric acid from bisulphates.—Orfila proposes to remove free sulphuric acid by agitating the concentrated liquor with sulphuric ether, and separating and evaporating off the ether; for he holds that all neutral and acid salts of sulphuric acid are insoluble in ether.[^[241]] This proposal is unaccountable. Simon stated in his paper three years before, that ether does not remove sulphuric acid from watery fluids containing it. And Dr. Douglas Maclagan and I, on inquiring into the matter, found that we could not, by means of ether, separate a particle of sulphuric acid from an ounce of rice soup and mucilage to which ten drops of the acid had been added. The process of Orfila for establishing the absence of bases in a simple watery solution is applicable to organic mixtures also, after incineration. But if bases be present in material quantity, all the difficulties now in question remain in full force.

b. When the mixture is neutral, sulphuric acid may be detected in it by the first steps of the preceding process. But the inference, that it once existed free can only be drawn when the subject of examination is not in a state of decay, when the quantity of sulphate of baryta obtained is considerable, when the administration of an antidote is proved, and when the ashes after incineration contain the antacid base which is said to have been administered. Even then the inference is only presumptive.

Section II.—Of the Mode of Action of Sulphuric Acid, and the Symptoms caused by it in Man.

It was formerly observed that the action of the strong mineral acids is independent of the function of absorption. They act by the conveyance along the nerves of an impression produced by the irritation or destruction of the part to which they are applied. There is very little difference between the three acids in the symptoms they excite or the action they exert.

When sulphuric acid is introduced directly into a vein it causes death by coagulating the blood. Thus, when Professor Orfila injected in the jugular vein of a dog half a drachm diluted with an equal weight of water, he observed that the animal at once struggled violently, stretched out its limbs, and expired; and on opening the chest immediately, he found the heart and great vessels filled with coagulated blood.[^[242]]—Nitric acid and hydrochloric acid act in the same way.

If, on the other hand, they are introduced into the stomach, the blood as usual remains fluid for some time after death; the symptoms are referrible almost solely to the abdomen; and in the dead body the stomach is found extensively disorganised, and the other abdominal viscera sometimes inflamed. If the dose be large, and the animal fasting, death may take place in so short a time as three hours: but in general it lives much longer.[^[243]]

When the strong mineral acids are applied outwardly, they irritate, inflame, or corrode the skin. The most rapid in producing these effects is the nitric, or rather the nitrous acid. The strong, fuming nitrous acid even causes effervescence when dropped on the skin.

Orfila has proved that sulphuric acid, as well as the two other mineral acids, is absorbed; for they may be detected in the urine, when they are introduced either into the stomach or through a wound.[^[244]] He could not succeed, however, in detecting any of them in the liver or spleen; in which organs it will be seen, hereafter, that various other poisons may be discovered by chemical analysis. But Mr. Scoffern seems to have found sulphuric acid in the kidney, even although the individual survived the taking of the poison nearly two days.[^[245]] It is also worthy of remark, that, as will be proved presently, these acids may pass through the coats of the stomach by transudation, and so be found on the surface of the other organs in the belly.

Toxicology is indebted to M. Tartra for the first methodic information published respecting the symptoms caused in man by sulphuric acid and the other mineral acids:[^[246]] but many important additional facts have been made known by numberless cases of poisoning which have since appeared, chiefly in the periodic journals.

The symptoms caused by all the three acids are so nearly the same, that after a detailed account of those occasioned by sulphuric acid, it will not be necessary to add much on the subject under the head of nitric and muriatic acid.

M. Tartra considers that four varieties may be observed in the effects of the mineral acids. 1. Speedy death from violent corrosion and inflammation; 2. Slow death from a peculiar organic disease of the stomach and intestines; 3. Imperfect recovery, the person remaining liable ever after to irritability of the stomach; 4. Perfect recovery.

1. The most ordinary symptoms are those of the first variety,—namely, all the symptoms that characterise the most violent gastritis, accompanied likewise with burning in the throat, which is increased by pressure, swallowing, or coughing;[^[247]]—eructations proceeding from the gases evolved in the stomach by its chemical decomposition;—and an excruciating pain in the stomach, such as no natural inflammation can excite. The lips are commonly shrivelled, at first whitish, but afterwards brownish in the case of sulphuric acid. Occasionally there are also excoriations, more rarely little blisters. Similar marks appear on other parts of the skin with which the acid may have come in contact, such as the cheeks, neck, breast, or fingers; and these marks undergo the same change of colour as the marks on the lips. I had an opportunity of witnessing this in the case of the man who was disfigured by the Macmillans (p. [122]) with sulphuric acid. He was cruelly burnt on the face as well as on the hands, which he had raised to protect his face; and the marks were at first white, but in sixteen hours became brownish. The inside of the mouth is also generally shrivelled, white, and often more or less corroded; and as the poisoning advances, the teeth become loose and yellowish-brown about the coronæ. The teeth sometimes become brown in so short a time as three hours.[^[248]] Occasionally the tongue, gums, and inside of the cheeks are white, and as it were polished, like ivory.[^[249]] There is almost always great difficulty, and sometimes complete impossibility, of swallowing. In the case of a child related by Dr. Sinclair, of Manchester, fluids taken by the mouth were returned by the nose; and the reason was obvious after death; for even then the pharynx was so much contracted as to admit a probe with difficulty.[^[250]] On the same account substances taken by the mouth have been discharged by an opening in the larynx which had been made to relieve impending suffocation. The matter vomited, if no fluids be swallowed, is generally brownish or black, and at first causes effervescence, if it falls on a pavement containing any lime. Afterwards this matter is mixed with shreds of membrane, which resemble the coats of the stomach, and sometimes actually consists of the disorganised coats, but are generally nothing more than coagulated mucus. The bowels are obstinately costive, the urine scanty or suppressed; and the patient is frequently harassed by distressing tenesmus and desire to pass water. The pulse all along is very weak, sometimes intermitting, and towards the close imperceptible. It is not always frequent; on the contrary, it has been observed of natural frequency, small and feeble in a patient who survived fifteen days.[^[251]] The countenance becomes at an early period glazed and ghastly, and the extremities cold and clammy. The breathing is often laborious, owing to the movements of the chest increasing the pain in the stomach,—or because pulmonary inflammation is also at times present,—or because the admission of air into the lungs is impeded by the injury done to the epiglottis and entrance of the larynx. To these symptoms are added occasional fits of suffocation from shreds of thick mucus sticking in the throat, and sometimes croupy respiration, with sense of impending choking.

Such is the ordinary train of symptoms in cases of the first variety. But sometimes, especially when a large dose has been swallowed, instead of these excruciating tortures, there is a deceitful tranquillity and absence of all uneasiness. Thus, in the case of a woman who was poisoned by her companions making her swallow while intoxicated aqua-fortis mixed with wine, although she had at first a good deal of pain and vomiting, there were subsequently none of the usual violent symptoms; and she died within twenty hours, complaining chiefly of tenesmus and excessive debility.[^[252]] Occasionally eruptions break out over the body:[^[253]] but their nature has not been described.

Death is seldom owing to the mere local mischief, more generally to sympathy of the circulation and nervous system with that injury. According to Bouchardat death arises from the acid entering the blood in sufficient quantity to cause coagulation.[^[254]] But although this certainly happens sometimes to the blood in the vessels of the stomach and adjacent organs, as will be proved under the head of the morbid appearances, there is no evidence that the same takes place throughout the blood-vessels generally, or in the great veins and heart in particular. Bouchardat’s proofs of the detection of sulphuric acid in the blood are not satisfactory.

The duration of this variety of poisoning with the acids is commonly between twelve hours and three days. But sometimes life is prolonged for a week[^[255]] or a fortnight;[^[256]] and sometimes too death takes place in a very few hours. The shortest duration among the numerous cases of adults mentioned by Tartra is six hours;[^[257]] but Dr. Sinclair, of Manchester, has related a case which lasted only four hours and a half;[^[258]] a man lately died in the Edinburgh Infirmary within four hours; and Professor Remer of Breslau once met with a case fatal in two hours.[^[259]]

The quantity required to produce these effects has not been ascertained, and must be liable to the same uncertainty here as in other kinds of poisoning. The smallest fatal dose of sulphuric acid I have hitherto found recorded was one drachm. It was taken with sugar by mistake for stomachic drops by a stout young man, and killed him in seven days.[^[260]] An infant of twelve months has been killed in twenty-four hours by half a tea-spoonful, or about thirty minims.[^[261]] A man has recovered after taking six drachms.[^[262]]

2. The second variety of symptoms belong to a peculiar modification of disease, which is described by Tartra in rather strong language. It begins with the symptoms already noticed; but these gradually abate. The patient then becomes affected with general fever, dry skin, spasms and pains of the limbs, difficult breathing, tension of the belly, salivation, and occasional vomiting, particularly of food and drink. Afterwards membranous flakes are discharged by vomiting, and the salivation is accompanied with fœtor. These flakes are often very like the mucous membrane of the stomach and intestines; and such they have often been described to be. More probably, however, they are of adventitious formation; for the mere mucous coat of the alimentary canal cannot supply the vast quantity that is evacuated. There is no doubt, however, that the lining membrane of the alimentary canal is occasionally discharged. Dr. Wilson has mentioned an instance of the ejection by coughing of about nine inches of the cylindrical lining of the pharynx and gullet six days after sulphuric acid was taken.[^[263]] Sometimes worms are discharged dead, and evidently corroded by the poison.[^[264]] Digestion is at the same time deranged, the whole functions of the body are languid, and the patient falls into a state of marasmus, which reduces him to a mere skeleton, and in the end brings him to the grave. Death may take place in a fortnight, or not for months. In one of Tartra’s cases the patient lived eight months. The vomiting of membranous flakes continues to the last.

3. The third variety includes cases of imperfect recovery. These are characterized by nothing but the greater mildness of the primary symptoms, and by the patient continuing for life liable to attacks of pain in the stomach, vomiting of food and general disorder of the digestive function.

4. The last variety comprehends cases of perfect recovery, which are sufficiently numerous even under unpromising appearances. From the average of 55 cases recorded by Tartra it appears that the chances of death and recovery are nearly equal. Twenty-six died, 19 of the primary, 7 of the secondary disorder. Twenty-nine recovered, and of these twenty-one perfectly. Suicidal are for obvious reasons more frequently fatal than accidental cases.

Tartra has not taken notice in his treatise of another form of poisoning with the strong acids,—in which the injury is confined to the gullet and neighbouring parts. In Corvisart’s Journal there is the case of a man, who began to drink sulphuric acid for water while intoxicated, but suddenly found out his error before he had swallowed above a few drops; and consequently the chief symptoms were confined to the throat. After his physician saw him he was able to take one dose of a chalk mixture; but from that time he was unable to swallow at all for a fortnight.[^[265]] Martini likewise met with a similar instance of complete dysphagia from stricture in the gullet caused by sulphuric acid.[^[266]] His patient recovered.

It also appears exceedingly probable, that the strong acids may cause death, without reaching the stomach or even the gullet, by exciting inflammation and spasm of the glottis and larynx. Such an effect may very well be anticipated from an attempt to commit murder with these poisons; as the person, if he retains consciousness at the time, may become aware of their nature before he has swallowed enough to injure the stomach.

Thus, Dr. A. T. Thomson says in 1837, that he once met with the case of a child, who, while attempting to swallow strong sulphuric acid by mistake for water, died almost immediately, to all appearance from suffocation caused by contraction of the glottis; and it was ascertained after death that none of the poison had reached the stomach.[^[267]] Professor Quain describes a similar case, occurring also in a child, where impending death was prevented by artificial respiration, and acute bronchitis ensued, which proved fatal in three days. In this instance thickening of the epiglottis and great contraction of the upper opening of the larynx showed the violent local injury inflicted there, inflammation could be traced down the trachea into the bronchial tubes, but no trace of injury could be detected in the gullet and stomach.[^[268]] In a very interesting and carefully detailed case by Mr. Arnott, where the poison taken was the nitric acid, the injury was confined in a great measure to the gullet and larynx,—the stomach, which was distended with food at the time, being very little affected. The chief symptoms at first, besides great general depression, were croupy respiration and much dyspnœa, which became so urgent, that laryngotomy was performed, and with complete relief to the breathing. But the patient nevertheless rapidly sunk under the symptoms of general exhaustion, and died in thirty-six hours without presenting any particular signs of the operation of the poison on the stomach; and the traces of action found there after death were trifling.[^[269]]

The importance of the fact established by these cases will appear from the following medico-legal inquiries. A Prussian medical college was consulted in the case of a new-born child, in which the stomach and intestines were healthy, and did not contain poison, but in which the cuticle of the lips was easily scraped off, the gums, tongue, and mouth yellowish-green, as if burnt, the velum and uvula in the same state, the rima glottidis contracted, and the epiglottis, larynx, and fauces violently inflamed. The College declared, that a concentrated acid had been given, and that death had been occasioned by suffocation. Sulphuric acid was found in the house; and the mother subsequently confessed the crime.[^[270]] A case was formerly quoted (p. [75]), where MM. Ollivier and Chevallier found traces of the action of nitric acid on the lips, mouth, throat and upper fourth of the gullet, but not lower. In this instance the reporters came to the opinion from the absence of injury in the more important parts of the alimentary canal, as well as from the marks of nail scratches on the neck, and the gorged state of the lungs, that death had been produced by strangling, after an unsuccessful attempt by the forcible administration of nitric acid. It is quite possible, however, that death might quickly ensue from the effects of the poison on the throat and gullet. In the course of the judicial inquiries M. Alibert stated that he had known repeated instances of death from swallowing nitric acid, although none of it reached lower down than the pharynx. Ollivier in his paper doubts the accuracy of this statement; but the cases quoted above show clearly that such injury may be done to the glottis as will be adequate of itself to occasion death.[^[271]]

It seems farther not improbable that, among the terminations of poisoning with the strong mineral acids, scirrhous pylorus must also be enumerated. This is a very rare effect of the action of corrosive poisons. But M. Bouillaud has related an instance of death from scirrhous pylorus in its most aggravated shape, which supervened on the chronic form of the effects of nitric acid, and which proved fatal in three months.[^[272]]

In some circumstances the stomach seems to acquire a degree of insensibility to the action of the strong acids. Tartra, in alluding to what is said of certain whisky-drinkers acquiring the power of swallowing with impunity small quantities of the concentrated acids, has related the case of a woman at Paris, who, after passing successively from wine to brandy and from that to alcohol, at last found nothing could titillate her stomach except aqua-fortis, of which she was seen to partake by several druggists of veracity.[^[273]] The fire-eating mountebanks too are said to acquire the same power of endurance; but much of their apparent capability is really legerdemain. On the other hand, a very extraordinary sensibility to the action of the diluted mineral acids has been supposed to exist in the case of infants at the breast,—so great a sensibility, that serious symptoms and even death itself have been ascribed to the nurse’s milk becoming impregnated with sulphuric acid, in consequence of her having taken it in medicinal doses. By two writers in the London Medical Repository griping pains, tremors and spasms have been imputed to this cause;[^[274]] and a writer in the Medical Gazette says he has seen continued griping, green diarrhœa and fatal marasmus ensue,—apparently, he thinks, from ulceration of the gastro-intestinal mucous membrane.[^[275]] Without questioning the great delicacy and tenderness of that membrane in infants, I must nevertheless express my doubts whether so small a quantity taken by a nurse, amounting in the cases in question only to four or six drops a day, could really produce fatal or even severe effects on her child.

Sulphuric acid is not less deadly when admitted into the body through other channels besides the mouth. Thus, it may prove fatal when introduced into the rectum. A woman at Bruges in Belgium had an injection administered, in which, being prepared hastily in the middle of the night, sulphuric acid had been substituted by mistake for linseed-oil. The patient immediately uttered piercing cries, and passed the remainder of the night in excessive torture. In the morning the bed-clothes were found corroded, and a portion of intestine had apparently come away; and she expired not long afterwards.[^[276]]

Death may also be occasioned by the introduction of this acid into the ear. Dr. Morrison relates a case of the kind, where nitric acid, which is analogous in action, was poured by a man into his wife’s ear, while she lay insensible from intoxication. She awoke in great pain, which continued for two or three days. In six days an eschar detached itself from the external passage of the ear; and this was followed by profuse hemorrhage, which recurred daily more or less for a month. On the day after the eschar came away, and without any precursory symptom referrible to the head, she was attacked with complete palsy of the right arm, and in eight days more with tremors and incomplete palsy of the rest of that side of the body. These symptoms subsequently abated; but they again increased after an imprudent exertion, and she died in a state of exhaustion seven weeks after the injury. The whole petrous portion of the temporal bone was found carious, but without any distinct disease of the brain or its membranes.[^[277]]

Sulphuric acid and the other mineral acids are equally poisonous when inhaled in the form of gas or vapour; and they then act chiefly by irritating or inflaming the mucous membrane of the air-passages and lungs. For some observations on their effects in this form both on plants and animals the reader may refer to the Chapter on Poisonous Gases.

Sulphuric acid belongs to the poisons alluded to under the head of General Poisoning,—of whose operation satisfactory evidence may be occasionally drawn from symptoms only. If immediately after swallowing a liquid which causes a sense of burning in the throat, gullet, and stomach, violent vomiting ensues, particularly if the vomited matter is mixed with blood; if the mouth becomes white, and stripped of its lining membrane, and the cheeks, neck, or neighbouring parts show vesications, or white, and subsequently brown excoriated spots;—if the clothes show red spots and are moist and disintegrated there,—I cannot see any objection to the inference, that either sulphuric or muriatic acid has been taken. In this opinion I am supported by a good authority, Dr. Mertzdorff, late medical inspector at Berlin.[^[278]]

Section III.—Of the Morbid Appearances caused by Sulphuric Acid.

The outward appearance of the body in cases of Tartra’s first variety in the action of the acids is remarkably healthy; every limb is round, firm, and fresh-looking.

On the lips, fingers, or other parts of the skin, spots and streaks are found where sulphuric acid has disorganized the cuticle. These marks are brownish or yellowish-brown, and present after death the appearance of old parchment or of a burn; sometimes there are little blisters.[^[279]]

The lining membrane of the mouth is more or less disorganized, generally hardened, and whitish or slightly yellowish. The pharynx is either in the same state, or very red or even swelled. The rima glottidis, as in the case described by Dr. Sinclair and in that of Mr. Arnott, is sometimes contracted, the epiglottis swelled, or on the contrary shrivelled, and the commencement of the larynx inflamed.[^[280]] The gullet is often lined with a dense membrane, adhering firmly, resembling the inner coat, but probably in general a morbid formation; and the subjacent tissue is brown or red. Sometimes, however, the inner coat or epithelian of the gullet loses its vitality, and is detached in part or altogether. In Mr. Arnott’s case the pharynx and upper gullet were lined by a pale lemon-coloured membrane, which in the lower two-thirds of the canal was completely detached and was plainly the œsophageal membrane; in the case related by Mertzdorff, the whole inner coat of the gullet, as well as that of the throat, epiglottis, and mouth, was stripped from the muscular coat;[^[281]] and in Dr. Wilson’s case (p. [131]), which proved fatal in ten months, the upper third of the gullet shone like an old cicatrix, and the lower two-thirds were narrowed, vascular, and softened on the surface.[^[282]] In a few rare cases of chronic poisoning with the mineral acids the gullet is found perforated by an ulcerative process;[^[283]] but it is never perforated by their corrosive action in quickly fatal cases. Occasionally the gullet is not affected at all, though both the mouth and the stomach are severely injured; and an instance has even been published where the acid, in this instance the nitric, left no trace of its passage downwards till near the pylorus.[^[284]]

The outer surface of the abdominal viscera is commonly either very vascular or livid, or bears even more unequivocal signs of inflammation, namely, effusion of fibrin and adhesions among the different turns of intestine; and these appearances may take place although the stomach is not perforated.[^[285]] The cause of this appearance, which is seldom observed in poisoning with other irritants, more especially with the metallic irritants, is that the acid passes through the membranes of the stomach by transudation during life,—as will be proved immediately. It must be observed, that the peritonæum is sometimes quite natural after death from sulphuric acid, even although the stomach was perforated. I have seen this in a case which proved fatal in twelve hours. An important appearance in the abdomen, to which less attention has been hitherto paid than it deserves, is gorging of the vessels beneath the peritonæal membrane of the stomach and adjoining organs with dark, firmly coagulated blood, arising from the acid having transuded through the membranes and acted on the blood chemically. My attention was first turned to this appearance by an interesting case, which I saw in 1840 in the Royal Infirmary of this city, and of which an able account has been published by Dr. Craigie.[^[286]] The whole vessels of the stomach were seen externally to be most minutely injected and gorged, and the blood in them was coagulated into firmly-cohering cylindrical masses, as if the vessels had been successfully filled with the matter of an anatomical injection. This appearance was also observed in the superior mesenteric arteries, in the omental vessels, and over the greater part of the mesentery. It was occasioned by the chemical action of the acid coagulating the colouring matter and albumen; for the clotted blood was strongly acid to litmus-paper. So too was the peritoneal surface of the stomach, omentum and intestines. And the acid had transuded through the stomach and into the omentum and tissues of the intestines during life; for in the first place, there was no perforation of the stomach, and secondly, I ascertained that there was no free acid either in the matter discharged from the stomach before death after the free administration of antacids, or in the contents of the stomach obtained at the examination of the dead body.

The stomach, if not perforated, is commonly distended with gases. It contains a quantity of yellowish-brown or black matter, and is sometimes lined with a thick paste composed of disorganized tissue, blood and mucus. The pylorus is contracted.

The mucous membrane is not always corroded. If the acid was taken diluted, the coats may escape corrosion; but there is excessive injection, gorging, and blackness of the vessels, general blackness of the membrane, sometimes even without softening, as in a case related by Pyl of a woman who first took aqua-fortis and then stabbed herself.[^[287]] More commonly, however, along with the blackness there is softening of the rugæ or actual removal of the villous coat, and occasionally regular granulated ulceration with puriform matter on it.[^[288]] The stomach is not always perforated. But if it is, the holes are commonly roundish, and the coats thin at the margin, coloured, disintegrated, and surrounded by vascularity and black extravasation. In some rare cases there is no mark of vital reaction except in the neighbourhood of the aperture. A case of this kind is related by Mertzdorff: The margin of the hole was surrounded to the distance of half an inch with apparent charring of the coats, and this areola was surrounded by redness; but the rest of the stomach was grayish-white.[^[289]] I examined with the late Dr. Latta of Leith a similar case, where the limitation of the injury was evidently owing to the stomach having been at the time filled with porridge. The patient, a child two years old, died in twelve hours; and on the posterior surface of the fundus of the stomach, towards the pylorus, there was a hole as big as a half-crown, which was surrounded to the distance of an inch with a black mass formed of the disorganized coats, and of incorporated charred blood. But the rest of the stomach was quite healthy. The most remarkable instance of chemical destruction of the coats yet known to me is a case mentioned by Mr. Watson of this city, where suicide was effected by cutting the throat about half an hour after two ounces of sulphuric acid had been swallowed. The individual was at first thought to have died simply of the wound of the throat. But on dissection the usual signs of acid poisoning were found; and among other effects, it was observed that nearly three-fourths of the stomach had been entirely destroyed.[^[290]] The perforation, if the patient lives long enough, is generally accompanied with a copious effusion into the belly of the usual muddy liquor of peritonitis; and the outer surface of the viscera feels unctuous, as if from a slight chemical action of the acid on them. The acid has actually been found in the contents poured out from the stomach into the sac of the peritonæum.[^[291]]

One would expect to find the acid always in the stomach when it is perforated. Nevertheless it is sometimes almost all discharged. In Mertzdorff’s case, that of an infant who was killed in twelve hours, a hole was found in the stomach ¾ths of an inch in diameter, and the contents of the stomach were effused into the belly: yet by a careful analysis the whole acid he could procure from the contents and tissues together was only 4½ grains. Sometimes of course the disappearance of the acid may be owing, as in Dr. Craigie’s case, to the effectual administration of antacids during life.

The inner coat of the duodenum often presents appearances closely resembling those of the stomach. Sometimes, however, as in the case just related from Mertzdorff, and in the infant I examined, the inner coat of the small intestines is not affected at all, probably because in such rapid cases the pylorus retains a state of spasmodic contraction till death or even after it.

The urinary bladder is commonly empty. The thoracic surface of the diaphragm is sometimes lined with lymph, indicating inflammation of the chest. In the case which was fatal in two hours [p. [131]], Professor Remer found the surface of the lungs, as well as that of the liver and spleen, brown and of a leathern consistence, and the tissue beneath scarlet;—appearances which he thinks arose from the acid penetrating in vapour and acting chemically. I have not found this appearance mentioned by any other writer; but I have seen it in animals poisoned with oxalic acid. The blood in the heart and great vessels has been several times seen forming a firm black clot. Kerkring[^[292]] relates an instance of the kind; in Dr. Latta’s case the appearance was very distinct; and it is dwelt on strongly in a recent paper by M. Bouchardat.[^[293]] Bouchardat thinks this state of the blood is simply the effect of the absorbed acid; but coagulation of the blood in the heart and great vessels,—a striking appearance in contradiction to what is observed after death from most other poisons,—is more probably the healthy state of the blood, and not the effect of the particular poison.

The general appearance of the body of those who have died of the second or chronic variety of poisoning with the acids, is that of extreme emaciation. The stomach and intestines are excessively contracted: The former has been found so small as to measure only two inches and a half from the cardia to the pylorus, and two inches from the lesser to the greater curvature.[^[294]] Tartra says the intestines are sometimes no thicker than a writing quill. They are in other respects sound outwardly, except that they sometimes adhere together.

Internally the pylorus is contracted. In a case of slow poisoning, fatal in three months, which has been described by Dr. Braun of Fürth, the chief appearance besides excessive emaciation was a thickening of the coats round and behind the pylorus to such a degree that the opening of the pylorus was formed of an almost cartilaginous ring several lines broad, and only wide enough to pass a quill.[^[295]] There are spots over the stomach apparently of regenerated villous tissue, smoother and redder than the natural membrane. At the points where the stomach adheres to the neighbouring organs, its coats are sometimes wanting altogether, so that when its connections are torn away, perforations are produced. The other parts of the body are natural.

It may in some circumstances be necessary to determine from the appearances in the dead body whether sulphuric acid has been the occasion of death or has been introduced into the body after death. This may always be easily done. If a few drachms of sulphuric acid be injected into the anus immediately after death, and the parts be examined in twenty-four hours, it will be found, that wherever the acid touches the gut, its mucous coat is yellowish and brittle, its muscular and peritonæal coats white, as if blanched, and the blood in the vessels charred; the injury is confined strictly to the parts actually touched, is surrounded by an abrupt line of demarcation, and shows no sign of inflammatory redness. Nitric acid produces nearly the same effects. The whole tunics are yellow, and the disorganization is greater. For these facts we are indebted to Orfila.[^[296]]

In closing this account of the morbid appearances, some observations will be required on the force of evidence derived from them; because circumstances may exclude all other branches of medical proof. In many instances both of acute and of chronic poisoning with the strong acids, I conceive, contrary to the general statements of most systematic writers on modern medical jurisprudence, that distinct evidence might be derived from morbid appearances only. Thus, what fallacy can intervene to render the following opinion doubtful? In a case several times alluded to as described by Mertzdorff, there were vesicles and brown streaks on the lips, neck, and shoulders, similar to the effects of burning,—almost total separation of the lining membrane of the mouth, throat, epiglottis, and gullet,—perforation of the stomach, with a margin half an inch wide, which was extensively charred, and surrounded by a red areola. From the appearances alone Mertzdorff declared that the child must have been poisoned with sulphuric acid. Perhaps he should have said sulphuric or muriatic acid.

Or take the case of Richard Overfield, who was condemned at Shrewsbury Assizes in 1824 for murdering his own child, a babe three months old, by pouring sulphuric acid down its throat. In the dead body the following appearances were found: The lips were blistered internally and of a dark colour externally; the gullet was contracted and its inner coat corroded; the lining membrane of the mouth and tongue of a dull white colour; the great curvature of the stomach corroded and converted into a substance like wet brown paper; the stomach perforated and a bloody-coloured fluid in the sac of the peritonæum.[^[297]] If to these appearances be added the fact that the child’s dress was reddened, what is there to prevent the medical jurist from declaring, without reference to chemical evidence, that this case must have been one of poisoning by sulphuric acid or some other mineral acids?

In like manner in the case of Mrs. Humphrey, who was condemned at Aberdeen in 1830 for murdering her husband by pouring sulphuric acid down his throat while he was asleep, there was found, on examining the dead body, two brown spots on the outside of the lips,—whiteness of the inside of the lips and of the gums,—glazing of the palate,—redness, with here and there ash-coloured discoloration, of the uvula, posterior part of the throat, pharynx and epiglottis,—abrasion of most of the inner coat of the gullet,—erosion and dark-red ulceration of the inner coat of the stomach in winding furrows. When to these appearances it is added, that the man was in good health only forty-seven hours before death, and was taken ill instantaneously and violently with burning pain in the throat and stomach,[^[298]] it is not easy to see what other opinion could be formed of the case, unless that he died of poisoning with a mineral acid, and probably with sulphuric acid.

Among the appearances justifying an opinion where chemical evidence happens to be wanting, not the least important seems to me to be the peculiar turgescence and induration of vessels under the peritonæum of the stomach and neighbouring organs, occasioned by the chemical coagulation of blood in them. It is an appearance, which, when once seen, cannot be confounded with any natural morbid phenomenon I have ever witnessed.

I am far from desiring to encourage rashness of decision, or to revive the loose criterions of poisoning relied on in former times. But there cannot, in my opinion, be a rational doubt that in the instance of sulphuric acid there may often be distinct exceptions to the general law regarding the feebleness of the evidence from morbid appearances; and that a witness would certainly be guilty of thwarting the administration of justice, if, relying on general rules, he refused to admit such exceptions. What natural disease could produce appearances like those described above? Assuredly no form of spontaneous perforation bears any resemblance to that caused in most cases of death from sulphuric acid; nor is it easy to mention any combination of natural diseases which could produce the peculiar conjunction of appearances remarked in the case of the man Humphrey.

Section IV.—Of the Treatment of Poisoning with Sulphuric Acid.

Since this acid and the other mineral acids act entirely as local irritants, it may be inferred that their poisonous action will be prevented by neutralizing them. But in applying that principle to the treatment it is necessary to bear in mind their extremely rapid operation; for if much time is lost in seeking for an antidote, irreparable mischief may be caused before the remedy is taken. Should it be possible then to administer chalk or magnesia without delay, these are the antidotes which ought to be preferred; but it may be well for the physician to remember, that in the absence of both he may at once procure a substitute in the plaster of the apartment beat down and made into thin paste with water. M. Chevallier, in a paper on the antidotes for the mineral acids, quotes five cases of poisoning with sulphuric acid and two with nitric acid, where life seems to have been saved by the speedy and free administration of magnesia, although in some cases so large a quantity as two ounces of the poison had been swallowed.[^[299]]—A solution of soap is another antidote of no small value. While the antidote is in preparation, the acid should be diluted by the free use of any mild fluid, such as milk or oleaginous matters.—The alkaline bicarbonates are also excellent antidotes; but their carbonates are ineligible, being themselves possessed of corrosive properties. In a paper on poisoning with the mineral acids by Dr. Lunding of Copenhagen, the author is disposed to ascribe the large proportion of deaths in his practice to the system pursued in the Copenhagen hospital of administering carbonate of potass as an antidote daily for weeks together.[^[300]] On the other hand however it may be mentioned, that in a late memoir, on this description of poisoning Dr. Ebers of Breslau endeavours to show, that there is no reason to dread the administration of the alkaline carbonates, even the carbonate of potash, provided they be given with mucilaginous fluids and syrup in a rather concentrated form; and he gives three cases illustrative of the good effects of this mode of treatment, which he maintains to be free of all danger, and preferable to every other antidotal method, because the remedy may be administered in small volume,—an advantage possessed by it especially over chalk or magnesia.[^[301]]

After the proper antidote has been given to a sufficient extent, the use of diluents ought to be continued, as they render the vomiting more easy.—Some have recommended the stomach-pump for administering antidotes and diluents; but this is unnecessary. When it is wished to evacuate the stomach, there is an advantage in allowing it to do so by its own efforts, if possible; because the evacuation is accomplished in this way more completely than by the stomach-pump. Besides, if the patient cannot swallow fluids, still less can he suffer the tube of the stomach-pump to be introduced. On several occasions, indeed, it has been found impracticable to introduce it.[^[302]]

The treatment of the surpervening inflammation does not differ from that of inflammation of the stomach. Where there is great difficulty of breathing, evidently from obstruction of the larynx, and where the absence of abdominal pain, tension or vomiting affords a presumption that little injury has been done to the stomach, laryngotomy appears an advisable remedy, and has been known to give very great relief.[^[303]] But the patient may nevertheless die soon of the sympathetic disorder of the circulation.

II.—Of Poisoning with Nitric Acid.

Nitric acid is more frequently used as a poison abroad than in this country. But even in Britain it is not an uncommon cause of severe accidents and death.

Of the Tests for Nitric Acid.

1. When concentrated, nitric acid is easily known by the odour of its vapour, which is peculiar. When pure, the acid as well as its vapour is colourless; when mixed with nitrous acid it is of various tints, and generally yellow. The acid of commerce is at times rendered impure by sulphuric acid, a circumstance which must be attended to in applying the subsequent tests.—The simplest test for nitric or nitrous acid is the action of copper, lead, or tin. If any of these metals in small fragments, or powder, be thrown into either acid previously diluted with an equal volume of water, an effervescence takes place, which in the case of lead or copper is much accelerated by heat; nitric oxide gas is disengaged; and ruddy fumes of nitrous acid gas are formed when the gas comes in contact with the oxygen of the air. Another characteristic test, which has the advantage of being applicable on an extremely small scale, is morphia, the alkaloid of opium. This substance is turned in a few seconds to a beautiful orange-red colour by nitric acid, and after longer contact forms with it a bright yellow solution. No other acid has this effect. Muriatic acid, as Dr. O’Shaughnessey has remarked,[^[304]] does not act at all on morphia, and sulphuric acid chars and blackens it. When nitric acid is added to a solution of narcotin in sulphuric acid, the colour of the solution is changed from yellow to blood-red.[^[305]] When it is added to a solution of proto-sulphate of iron, the solution becomes brown, and the addition of sulphuric acid then alters the colour to violet.[^[306]] When it is added even in the most minute proportion to sulphuric acid, the addition of a few particles of the alkaloid brucia will render the whole fluid red, passing gradually to yellow.[^[307]]—Many other characteristic tests might be mentioned; but those now specified are more than enough.

2. In a diluted state this acid is not so easily recognised as the other mineral acids, for it does not form any insoluble salt or precipitate with bases.

The most convenient process consists in first ascertaining the acidity of the fluid, then neutralizing it with potass, evaporating to dryness, and heating the residue in a tube with sulphuric acid. The vapour disengaged, if abundant, may be known by its orange colour in the tube and its odour. But if small in quantity it is best to distil over the vapour in a proper apparatus, and to subject the condensed product to the tests of morphia, narcotin dissolved in sulphuric acid, and proto-sulphate of iron dissolved in water. A convenient tube for the purpose is that represented in Fig. 3; into which the materials are introduced by the funnel, Fig. 4. The wide part of the tube may then be drawn out in the spirit-lamp flame to any length or fineness that may be necessary, so as to conduct the vapour into another tube as a condenser, or directly into the substances to be used as tests.

3. When in a state of compound mixture, nitric acid, like sulphuric acid in similar circumstances, may be after a time partly decomposed and partly neutralized; and when the matter with which it is mixed belongs to either of the organic kingdoms, more particularly to the animal world, its decomposition is more rapid than that of sulphuric acid. Still it is an important fact, that some of the acid may be discovered after a considerable interval. M. Ollivier detected it in various stains on the skin at least a day after it had been applied;[^[308]] Dr. O’Shaughnessey detected it in a stain on cloth sent to him from Ireland to Edinburgh;[^[309]] and I have found it in stains made on broad-cloth with detached drops seven weeks before.

Process for Stains. Nitric acid produces on the skin a yellow stain, which gradually becomes dirty orange, and finally of a dirty yellowish-brown; but in all of these states it is at once rendered for a time lively yellow by the action of ammonia. I am not aware that any other yellow stain is similarly affected. Stains on cloth are generally yellow, reddish-yellow, or brownish-yellow, and are attended with more or less disintegration of the texture of the cloth. The method of analyzing all these stains is as follows:—The stained parts is to be boiled in a few drachms of pure water several times in succession; and the liquid is then filtered, and may be subjected to litmus-paper for the purpose of ascertaining its acidity. It is then to be rendered neutral, or for the sake of greater facility, feebly alkaline, by adding a few drops of a diluted solution of caustic potass, after which the whole is evaporated to dryness, and in a vapour-bath, if practicable. The residuum is then to be decomposed by sulphuric acid in the same way as recommended above for the simple diluted acid.—Orfila thinks it advantageous to let the stains macerate for some hours in a solution of bicarbonate of soda rather than to boil them in water. In that case, however, it is necessary to ascertain the acidity of the stains with litmus-paper before proceeding to macerate them.

Process for Mixtures. The detection of nitric acid in compound mixtures, such as the contents of the stomach, is not so easy a matter as its detection in stains; and indeed a sure and delicate process is still a desideratum in medico-legal chemistry. The process varies, as in the case of sulphuric acid, according as the subject of analysis is acid or neutral.

a. If the mixture be acid, and the proportion of the acid considerable, it maybe detected without difficulty. It is merely necessary to ascertain the acidity of the mixture by litmus-paper, to neutralize with potass, water being added if necessary, and then to filter and evaporate to a convenient degree of concentration. Crystals will form on cooling, which may be decomposed by sulphuric acid in the usual way. But the medical jurist ought not to flatter himself with the expectation of meeting often with a proportion large enough to admit of being discovered by so coarse a method of analysis. In general the crystallization of the nitrate of potass is prevented by co-existing animal or vegetable matter. When the proportion appears inconsiderable, therefore, a different process must be pursued. In preparing the former edition of this work, the present topic was investigated with some care, and a method suggested which appeared to me at that time more effectual, delicate, and conclusive than any previously made public. Since then Professor Orfila has also investigated the subject attentively, and after trying various methods, has ended in adopting one which is substantially the same as that now referred to, but without a precaution, which seems to me essential for success in certain probable enough circumstances.[^[310]] I am therefore disposed to retain my former process, with some variations and additions in the details.

Macerate the subject of analysis for a few hours in distilled water, if it be not already liquid enough; and then boil for a few minutes, and filter it. Ascertain now whether the fluid be acid to litmus; and if it be so, neutralize it with solution of potash, or as Orfila suggests, with a solution of the purer salt, the bicarbonate of soda. Evaporate gently, to obtain crystals if possible; and if these do not tend to the cubical form, distil them with sulphuric acid, and proceed as directed for nitric acid simply diluted. If crystals do not appear, or their form tend to the cube,—in which case chloride of sodium is present,—redissolve the whole residue of evaporation in distilled water; add a slight excess of a warm solution of acetate of silver, to throw down organic matter and the chlorine of any chlorides that may be present; filter and evaporate to dryness, and distil the residuum with sulphuric acid, applying as usual to the vapour the tests of litmus-paper and morphia,—also, as Orfila proposes, the solution of narcotin in sulphuric acid, and proto-sulphate of iron in water,—and if the quantity of vapour be great enough, the sense of smell and the action of copper with the condensed vapour.

b. If the mixture be neutral, proceed exactly as above, except that it becomes unnecessary to neutralize the liquid with potash or bicarbonate of soda. This variety in the process will be principally required, where earths or alkalis have been administered as antidotes.

The process now detailed requires a word or two of commentary.—Organic matter is inconvenient because it prevents the nitrate of potash or soda in the mixture from crystallizing. But it will not prevent the evolution of nitric acid vapour by distillation with sulphuric acid, even although the material be a simple extract without crystals. At the same time it is better to get rid of as much organic matter as possible, if distinct crystals be not obtained by evaporation. A more serious difficulty, however, to which Orfila does not advert, arises from the co-existence of a chloride. For, in that case, distillation with sulphuric acid may disengage not nitric acid, but chlorine, in consequence of the reaction which takes place between the nitric and hydrochloric acids in the act of being liberated. This is a more important reason for purifying the liquid by acetate of silver before subjecting it to concentration; but in addition, by removing organic matter, this precaution increases the chance of crystals of nitrate of potash or soda being obtained. Its necessity, where a chloride co-exists, will appear from the following experiment. Four drops of nitric acid neutralized with potass were mixed with six ounces of strong barley-broth; from which half an ounce of limpid fluid was procured by filtration. One-half of this evaporated to dryness gave a crystalline residue, which, heated with sulphuric acid in a tube, emitted a strong odour of chlorine; and the moisture which bedewed the tube scarcely affected morphia. The residuum of the other half of the filtered fluid was redissolved, treated with acetate of silver, again filtered, and evaporated to dryness; and the residue was gently heated in a tube with sulphuric acid. An odour of nitric acid was now disengaged, and the moisture on the tube close to the mixture turned a fragment of morphia to bright orange-red.

Acetate of silver is prepared by mixing strong solutions of acetate of potass and nitrate of silver, draining and compressing between folds of bibulous paper the crystalline precipitate which forms, dissolving this precipitate by agitating it in boiling water, and finally crystallizing the salt again by refrigeration. The crystals, which are sparingly soluble in cold water, should be then separated, slightly washed with a little water, and again dried by compression. When put to use, a solution should be made by agitating the salt in boiling water, because at low temperatures water retains very little of the salt; but actual ebullition should be avoided, because acetate of silver is thus quickly decomposed.

In all medico-legal analyses for nitric acid, care must be taken that the different reagents used are free of this acid, and also of nitrates. Sulphuric acid often contains a little nitric, or rather nitrous acid; which may be discovered by the sulphuric acid becoming brown or dark-red when a solution of proto-sulphate of iron is gently poured over it in a test-tube; and which may be removed either by boiling the acid with a few grains of sugar, according to the formula of the Edinburgh Pharmacopœia, or, as Orfila directs, by boiling it with sulphate of ammonia.

Sections II. III. IV.—Of the Action, Symptoms, Morbid Appearances, and Treatment of Poisoning with Nitric Acid.

All the observations made on these topics under the head of sulphuric acid apply, with few exceptions, to the nitric acid also. A few statements therefore on the peculiarities ascertained to exist in the latter case are all that will be required in the present sections.

Nitric acid is not less powerful as a corrosive and irritant than sulphuric acid. It will act with energy as an irritant even when considerably diluted, for example with six or eight parts of water or even more.—The lips which are rendered at first whitish by all the acids, and eventually brownish by sulphuric acid, becomes soon yellow with nitric acid. The tongue too sometimes acquires a yellow colour instead of a white glazed appearance; but this character is not invariable.—All spots caused by it on the skin become speedily yellow, and long retain this hue; or if the tint become dull, which generally happens in a few days, it is enlivened and the yellow colour restored for a time, by ammonia, potash, soda, or soap.—An important fact, for which toxicology is indebted to Professor Orfila, is that the acid may be often found in the urine, both when it had been swallowed, and when it had been introduced through the medium of the cellular tissue.[^[311]] It is to be discovered by the process for compound mixtures. Orfila adds that he has hitherto been unable to find it in the liver or spleen.

A difference of tint in the lining membrane of the mouth and gullet is the only difference observed in the morbid appearances caused by nitric and sulphuric acid. The former sometimes renders these parts yellow; but this appearance is far from being invariable.

The treatment in both instances is the same in every respect.

III.—Of Poisoning with Hydrochloric Acid.

This acid occurs more rarely than any of the other mineral acids in medico-legal cases; a fact which appears singular enough on considering, that it is a powerful corrosive, and more perhaps in the hands of the working-classes than any other.

Section I.—Of the Tests for Hydrochloric Acid.

Like the other acids, hydrochloric acid occurs in the concentrated shape, in a state of simple dilution, and mixed with various matters, especially from organic kingdoms.

1. Hydrochloric acid, in its concentrated state, is colourless, if pure, but yellowish as usually sold; and it is easily known by the peculiar appearance and odour of its fumes. A convenient additional test, which, however, is not absolutely distinctive, is the formation of white vapour when a rod dipped in it is brought near another dipped in ammonia. If any farther evidence be desired, the strong acid must be diluted with water, and examined by the tests for it in a diluted state.

2. When diluted, it is recognised with facility, first by litmus-paper, and then by the nitrate of silver, which forms with it a dense, white precipitate, the chloride of silver. This is soluble in ammonia, reappears on neutralizing the ammonia by nitric acid, and is not redissolved by a large excess of nitric acid, even aided by heat. Its permanence under an excess of nitric acid distinguishes it from every other silver salt, but the cyanide; which again is known by disappearing when boiled with a large excess of the acid.

3. In the last edition of this work I proposed for the detection of hydrochloric acid in compound organic mixtures a process, to which Professor Orfila has since made an important addition,[^[312]] and which the investigations of that toxicologist, as well as my own, lead me to suppose superior to any other yet suggested, although it is not entirely free from objection. This process divides itself into two, according as the subject of analysis is acid or neutral; but in the latter case its indications are of dubious import.

a. If the matter to be examined be acid, boil it with water if necessary, filter, and distil it with a gentle heat till the residue acquire the consistence of a very thin syrup. Subject the distilled liquor to the tests for diluted hydrochloric acid. It will seldom be found there, however, because it is apt to be retained by the co-existence of organic matter. If it be not found, add to the thin extract in the retort a slight excess of a strong solution of tannin, filter, and distil the filtered liquid by means of a hot bath of solution of hydrochlorate of lime (consisting of two parts of crystallized salt and one of water,)—taking care that the temperature of the bath never exceeds 240°; and stop the distillation just before the residuum becomes dry. Examine now the distilled liquor with the tests for diluted hydrochloric acid.

Hydrochloric acid has a tendency to adhere with obstinacy to organic matters, especially when these are abundant; and therefore Orfila properly proposes to remove organic principles as far as possible by precipitating them with solution of tannin. I have found, as he did, that the acid may be obtained by distillation after this measure, when it could not be obtained previously.—Orfila objects to the process however that hydrochlorate of ammonia will pass over in the distillation. But I have not found this to be the fact, when the temperature did not rise above 240°; which in his experiments seem to have been considerably exceeded.—A more important fallacy is, that hydrochloric acid will be indicated by the process in a mixture which contains both a neutral chloride, such as common salt, and sulphuric acid. This fallacy can only be obviated by ascertaining that sulphuric acid is not present.—But the most important fallacy of all is, that free hydrochloric acid constitutes an essential part of the gastric juice, and an ingredient of the secretions of the stomach in various states of disordered digestion.[^[313]] It is not easy to see how this fallacy can be obviated, unless the acid be obtained in large quantity; nor am I prepared to say what quantity would justify the conclusion, that the acid had been derived from an external source. Dr. Prout once found between four and five grains of pure acid in sixteen ounces of the fluid of water-brash.[^[314]] The quantity of hydrochloric acid is to be known by drying, heating and weighing the chloride of silver thrown down in the distilled fluid by nitrate of silver, and allowing 100 parts of concentrated commercial acid for 145 of chloride.

b. When the mixture is neutral, hydrochloric acid can be no longer detected in it without the aid of sulphuric acid to decompose the chloride that has been formed. This should be added to the filtered fluid obtained after organic matter has been separated by solution of tannin. Hydrochloric acid will then distil over.—It is seldom however that the discovery of the acid in this way will warrant the conclusion, that it had ever existed free in the mixture whence it is obtained. For it may have proceeded from chlorides contained in the subject of analysis from the first, more especially chloride of sodium, which exists in small quantity in all animal fluids and solids, and more largely in many articles of food and drink. The only circumstance indeed in which the detection of hydrochloric acid by decomposition with sulphuric acid will yield any evidence,—and even then the evidence will only be presumptive,—is when it is known that an earth or alkali was given as an antidote, and when the alkali or earth which was used is found in the suspected substance.

Section II.—Of the Action and Symptoms produced by Hydrochloric Acid.

Hydrochloric acid has been found by Professor Orfila to exert the same action as sulphuric and nitric acids; but it is a less powerful corrosive and irritant.—In the gaseous state, it is a most destructive poison to vegetables, as will be shown in the article on the Poisonous Gases.

The symptoms it occasions in man are very like those produced by sulphuric acid. As few cases however of poisoning with this substance have yet been published, its effects are not so well known as those of the other powerful acids; and it may therefore be right to mention the leading particulars of some of the cases which are met with in authors.—Mr. Quekett has related the case of a man, who, on arriving at home one day, told the woman he lodged with that he had poisoned himself with spirit of salt, but presented at the moment so little sign of uneasiness, that she at first scarcely believed him. In a short time however he suddenly became faint and fell down. On being removed to the London Hospital, magnesia and milk were given, about three hours after the acid had been taken; but no relief was experienced. He suffered intense thirst, complained of excessive pain in the stomach and throat, and expired in about fifteen hours.[^[315]]—Mr. J. F. Crawfurd of Newcastle has related a still more rapid case which was occasioned by two ounces of an equal mixture of hydrochloric acid and “tincture of steel,” probably the tincture of chloride of iron. Vomiting occurred soon afterwards, but subsequently ceased; there was no complaint made either of pain or heat anywhere, or of thirst; and questions were answered intelligently. But the pulse was imperceptible, and the muscles of the extremities contracted; and death took place in five hours and a half.[^[316]]—Orfila mentions that an hospital patient, affected with inflammation of the brain after a fall on the head, having got by mistake from his nurse 45 grammes, or two fluid ounces, of hydrochloric acid, was attacked with acute pain in the stomach, efforts to vomit, hiccup, extreme restlessness, a small pulse, a fiery red tongue, blackness of the lips, and a burning skin; and next day he died in a state of constant delirium, and covered with a cold clammy sweat.[^[317]]

These cases present nearly the same violence and variety of action with that which results from the two other acids.

Section III.—Of the Morbid Appearances caused by Hydrochloric Acid.

The morbid appearances are on the whole similar to what are caused by sulphuric acid. In Mr. Quekett’s case the stomach outwardly was leaden-coloured and its vessels gorged with black blood; the intestinal peritonæum injected and speckled with fibrinous effusion; the villous coat of the stomach lined with yellow, curdled milk, and itself irregularly black here and there, as if charred, and in some places softened and corroded, so that a rent was made in handling it; the inner membrane of the duodenum similarly affected, and also even the jejunum, though more irregularly. The contents of the stomach were not acid, and did not contain any chloride.—In Mr. Crawfurd’s case the villous coat presented black elevated ridges, as if charred, and the furrows between were scarlet-red; black granular extravasation had taken place at many points into the submucous tissue; similar appearances were seen in the duodenum and jejunum; and the lower part of the gullet looked as if it had been cauterized.—In the case related by Orfila the gullet and pharynx were red, and at one or two places excoriated; the stomach inflamed externally, and its inner membrane spotted with gangrenous (?) patches, and very brittle; the duodenum thickened, and the jejunum perforated by a round worm.

CHAPTER IV.
ON POISONING WITH PHOSPHORUS AND THE OTHER BASES OF THE MINERAL ACIDS.

Of Poisoning with Phosphorus.—The only other mineral acid that deserves mention is the phosphoric. It possesses properties nearly analogous, and hardly inferior to those of the three acids already mentioned. On its own account, however, it does not merit any notice here, since it is much too rare to be within reach of a person who intends to give or take poison. But it must be attended to, because it is formed in the course of the action of a more common poison, phosphorus. An attempt has actually been made to perpetrate murder by means of this substance. A woman at Mengshausen tried to poison her husband by putting into his soup a mixture of phosphorus, flour, and sugar, used for poisoning rats. But the soup having been kept warm on the stove, the man’s suspicions were excited by its phosphorescence, and phosphorus was detected in it.[^[318]]

Orfila found that two drachms of phosphorus given to dogs in fragments caused death in twenty-one hours, that the whole stomach and intestines were more or less inflamed, and that the phosphorus had lost much of its weight, though vomiting had been prevented by a ligature on the gullet; in fact the poison was partly oxidated. In a state of minute division, as when dissolved in oil, twenty-four grains caused death in less than five hours with all the symptoms of the most acute irritant poisoning; and after death the stomach was found extensively corroded, and perforated by two holes.[^[319]] Other experimentalists have found that half a grain melted in hot water could kill a dog;[^[320]] and that water, in which phosphorus had been simply received in the process for preparing it, proved in small quantities fatal to poultry.[^[321]]

There is no doubt, therefore, that phosphorus is a dangerous poison to animals. Its effects on man have not been often witnessed; but the observations hitherto made will show that it is not less injurious to him than to the lower animals. A grain and a half have actually proved fatal to man, as appears from a case mentioned by M. Worbe.[^[322]] The subject of the case was a stout young man who took a grain and a half in hot water, after having previously taken half a grain without sustaining injury. In seven hours, and not till then, he was attacked with pain in the stomach and bowels, then with incessant vomiting and diarrhœa, excessive tenderness and tension of the belly,—all the symptoms in short of irritant poisoning; and he died exhausted in twelve days. Another fatal case somewhat similar in its circumstances has been related by M. Julia-Fontenelle.[^[323]] An apothecary, after taking in one day first a single grain and then two grains of phosphorus without experiencing any particular effects, swallowed next day three grains at once in syrup. In the evening he felt generally uneasy, from a sense of pressure in the belly, which continued for three days; and then he was also seized with violent, continual vomiting of a matter which had an alliaceous odour. On the seventh day he had also spasms, delirium, and palsy of the left hand; and death speedily ensued.—Dr. Maier of Ulm relates a singular case occasioned by a portion of lucifer-match composition having been swallowed intentionally. Vomiting and pain in the belly ensued, then anxiety, restlessness, and excessive thirst, and death in about fifteen hours.[^[324]]—M. Martin-Solon relates the case of a patient, affected with lead palsy, who having taken considerably less than a grain in the form of emulsion, was attacked with burning along the gullet and in the stomach, mucous vomiting, tenderness of the belly, general coldness and feebleness of the pulse. Afterwards the pulse became imperceptible, the limbs neuralgic, the intellect clouded, and the breathing stertorous; and he died in little more than two days.[^[325]]—In the only other case I have hitherto found recorded death took place in forty hours, and the symptoms were violent pain in the stomach and continual vomiting, together with the discharge by clysters of small fragments of phosphorus, which were discovered by their shining in the dark, and subsequently by the appearance of burnt spots on the bed-linen. In this case, which is described by Dr. Flachsland of Carlsruhe,[^[326]] the quantity of the poison taken was not ascertained. The patient, a young man, took it on bread and butter at the recommendation of a quack, to cure constipation, general debility, and impotence.

At one time it was the custom to give small doses of phosphorus in medical practice; but the uncertainty and occasional severity of its operation have perhaps properly expelled it from most modern pharmacopœias. Among other properties ascribed to it in medicinal doses, it is said to be a powerful aphrodisiac: No such symptom occurred in the first of the fatal cases just related, or is mentioned in any of the others; but there is no doubt that medicinal doses sometimes produce it.

As to the morbid appearances, the same changes of structure may be expected as in the instance of the mineral acids generally. In Worbe’s case quoted above, the skin was generally yellow, and here and there livid; the lungs gorged with blood; the muscular coat of the stomach inflamed, but the other coats not, except near the two extremities of the organ, where they were black. In Flachsland’s case much fluid blood was discharged from the first incisions through the skin of the belly; the omentum and outside of the stomach and intestines were red; the villous coat of the stomach presented an appearance of gangrenous inflammation (probably black extravasation only); the inner membrane of the duodenum was similarly affected; the great intestines were contracted to the size of the little finger; the mesenteric glands enlarged; and the kidneys and spleen inflamed. In Maier’s case the peritonæum and omentum were dry and vascular, the stomach and small intestines pale, the great intestines contracted, almost empty, brownish-red, and here and there inflamed, the liver large, and the blood everywhere liquid. The contents of the caput cœcum had an odour of phosphorus, and here were found two yellowish lumps weighing eight grains, which shone when rubbed, exhaled a phosphoric odour, and contained 0·6 of a grain of phosphorus. In Martin-Solon’s case the gullet was cherry-red and its epithelian brittle, the villous coat of the stomach grayish and brittle, the solid viscera in the abdomen soft, and the cerebral membranes congested.

Phosphorous acid, the effects of which have been examined experimentally by Professor Hünefeld of Greifswalde, differs in its operation from phosphoric acid. Twenty-five grains had no effect on a rabbit; but a drachm caused difficult breathing, restlessness, bloody vomiting, slight convulsions, and death in twelve hours; and the stomach was found not much injured. The urine contained phosphoric acid.[^[327]]

Of Poisoning with Sulphur.—It does not appear that sulphur, which resembles phosphorus in many particulars, bears any resemblance to it in physiological properties;—which may be ascribed to its not being susceptible of spontaneous acidification. It certainly possesses, however, slight irritating properties. It is often given as a purgative, which is sufficient to prove that it is not altogether inert; and the veterinary school at Lyons found that a pound killed horses by producing violent inflammation, recognizable during life by the symptoms, and after death by the morbid appearances.[^[328]]

Of Poisoning with Chlorine.—Chlorine in its gaseous state acts powerfully as an irritant on the windpipe and lungs, and on that account will be noticed under the head of the poisonous gases. But even in solution it retains to a certain degree its poisonous qualities. Orfila says that five ounces of a strong solution of chlorine will kill a dog in twenty-four hours, if it is kept in the stomach by a ligature, and that two ounces diluted with twice its volume of water will prove fatal in four days;—that the symptoms are those of irritation of the stomach;—and that in the former case he found general redness and blackness—in the latter ulceration of its villous coat.[^[329]]

Of Poisoning with Iodine.

Iodine is a poison of more consequence than chlorine, both because it is becoming a more common article, and because it is more violent in its effects on the animal economy.

Tests of Iodine.—Iodine when pure is a solid substance easily known by its scaly form, its resemblance in colour and resplendence to polished iron, its peculiar odour, the violet fumes it forms when heated, and the fine blue colour it produces with a solution of starch. It is very sparingly soluble in water, but readily so in rectified spirit and in aqueous solutions of certain salts, more especially the iodide of potassium. Its ordinary forms in the shops are iodine itself, the tincture, and the compound solution, where the solvent is a solution of iodide of potassium in water. It stains the skin brownish-yellow; but the stain is not permanent. Its fumes are intensely irritating to the nostrils, throat, and lungs.

When dissolved in water or in solutions of neutral salts, it communicates to the fluid a yellowish-brown or reddish-brown colour, which is destroyed by sulphuretted hydrogen, because the iodine is converted into hydriodic acid. In the colourless fluid thus formed, if treated with chlorine,—or in the original brown fluid without chlorine,—a solution of starch, obtained by ebullition and subsequently cooled, produces a fine blue colour and precipitate; and these, if the solution be sufficiently diluted, disappear on boiling, reappear on sudden cooling, and are removed permanently by a stream of sulphuretted hydrogen. This is a very delicate and characteristic system of tests. The best mode of using chlorine for decomposing hydriodic acid is to let it descend in the gaseous form from the mouth of a bottle of nitro-hydrochloric acid upon the fluid to be examined; In this way an excess is easily avoided, which bleaches out the blue colour. Sulphuric acid, though often recommended for the purpose, does not act unless it contains nitrous acid,—from which however the sulphuric acid of commerce is seldom quite free.

When mingled with organic substances, the discovery of it is a matter of some nicety; because many substances of this nature, especially in the living body, quickly convert it into hydriodic acid.[^[330]] Hence few cases can occur in medico-legal practice, where iodine will be discoverable in its free state. The following method of analysis will meet all possible cases.

Process for Compound Mixtures.—Add water if necessary, and filter. If either the fluid or solid part is little or not at all coloured, test it with cold solution of starch, assisting the action of the test on the solid part by trituration in a mortar. If a blue colour be struck, which disappears under ebullition, and reappears under refrigeration alone, or on subsequently allowing chlorine gas to descend on the surface of the fluid, there can be no doubt of the existence of iodine.—If the colour of the suspected mixture after filtration is so deep that the action of the starch cannot be expected to yield characteristic appearances, then both the solid and fluid parts should be agitated with a third of their volume of ether; and after the ethereal solution has arisen to the surface, it is to be removed and tested with solution of starch. The blue colour will be now perhaps struck, because the ether, in carrying off the iodine from the mixture, leaves many coloured organic principles behind.

Should free iodine not be thus detected, strong presumptive evidence may still be procured of its actual presence, or of its having been at one time present, by continuing the examination with the view to detect hydriodic acid. This is described in p. [159].

By following this method of analysis, I have found that one grain of iodine of potassium, which is equivalent to three-quarters of a grain of iodine, may be easily discovered in six ounces of urine,—a fluid as complicated as can well be conceived.

The process adopted by Professor Orfila is so nearly the same with this, as scarcely to require being detailed. He uses nitric acid instead of chlorine for decomposing the hydriodic acid. Chlorine, however, is the most delicate reagent for the purpose, if it be used in the way described above.

Action of Iodine and Symptoms in Man.—Iodide has a twofold action, one local and irritating, the other general, and produced only when it has been administered long in frequent small doses.

Orfila remarked that in doses of two drachms it excited in dogs symptoms of irritation in the stomach; that death slowly ensued in seven days, without the symptoms having ever become very violent; and that the villous coat of the stomach was here and there yellow, had also patches of yellow mucus lining it, and exhibited numerous little ulcers of a yellow colour. He could not observe much injury from iodine introduced into the cellular tissue; and more lately, Dr. Cogswell remarked that in this way it merely induces phlegmonous inflammation and the usual consequences.[^[331]]

An important circumstance in regard to the physiology and medical jurisprudence of this poison and its compounds is, that it may undoubtedly be detected in the blood, both when a single large dose has been taken, and in those persons who have used it for some time medicinally. Cantu, an Italian experimentalist, discovered iodine in such circumstances in the blood, sweat, urine, saliva and milk;[^[332]] and Bennerscheidt, a German chemist, also found it in the blood, when it had been employed outwardly.[^[333]] In the latter instance it could not be detected in the serum, but it was detected in the crassamentum by means of starch. Some interesting facts of the same nature have also been ascertained by Dr. O’Shaughnessey, from which it appears that even in acute poisoning with this substance, satisfactory proof of its administration may be procured several days afterwards by analysing certain secretions. In a dog poisoned with iodine, he detected the poison in forty minutes in the urine, and occasionally in the same secretion so late as the fifth day, when it died. It is singular, however, that he could not find it in the same quarter on the third day, although it existed at that time abundantly in the saliva.[^[334]] In these experiments the iodine was always found in the form of hydriodic acid, having been converted into that compound in the alimentary canal. This change takes place with such rapidity, that on one occasion, in the vomited matter discharged by a dog fifteen minutes only after the administration of iodine, Dr. O’Shaughnessey could find no iodine, but a large quantity of hydriodic acid.[^[335]] Orfila has found it not only in the urine, but likewise in the liver of animals.[^[336]]

Considerable uncertainty prevails as to the circumstances in which we may expect iodine to be detected in the organs or secretions of persons who have taken it. Thus it has been stated by an Italian physician, Dr. Cristin, that in many individuals affected with dropsy, struma, epilepsy, and other diseases, he had sought for iodine to no purpose in the urine, bronchial mucus, and other excretory fluids.[^[337]]

With regard to its operation on man, Orfila says, he has tried the effects of four or six grains on himself, and that he found this dose produce a sense of constriction in the throat, sickness, pain in the stomach, and at length vomiting and colic. There is no doubt, therefore, that in larger doses it will prove a dangerous irritant to man as well as to dogs. Accordingly, Dr. Gairdner has noticed the case of a child four years old, who died in a few hours after taking about a scruple in the form of tincture;[^[338]] but he has not mentioned the symptoms. Dr. Jahn of Meiningen mentions a case where an over-dose produced violent pain in the belly, vomiting, profuse bloody diarrhœa, coldness and blanching of the skin, rigors, quivering of the sight and rapid pulse.[^[339]] Two similar cases are related in a recent French journal; in one, which was produced by a drachm and a half of the ioduretted solution of hydriodate of potass, nausea, with acute pain and sense of burning in the pit of the stomach, followed immediately; in an hour there was vomiting of a yellowish matter which had the taste of iodine; excessive restlessness ensued, with headache, giddiness and paleness of the countenance; and these symptoms were not entirely dissipated for five days.[^[340]] In the other case two drachms and a half of iodine were swallowed for the purpose of self-destruction. A sense of dryness and burning from the throat down to the stomach was immediately produced; lacerating pain in the stomach and fruitless efforts to vomit succeeded; and in an hour, when the relater of the case first saw the patient, there was suffusion of the eyes, excessive pain and tenderness of the epigastrium, and sinking of the pulse. Vomiting, however, was then brought on by warm water; copious yellow discharges, possessing the smell and taste of iodine, took place; and in nine hours the patient was well.[^[341]]

There is a singular uncertainty, however, in the action of one or more large doses. Magendie says he has taken two drachms of the tincture, containing about ten grains of iodine, without injury;[^[342]] Dr. Gully, that he has given three times as much daily for some time; Dr. Kennedy, that he gave an average of twelve grains daily in the form of tincture for eighty days without observing any effect at all; and Mr. Delisser, that he has given a patient thirty grains in a day without injury.[^[343]] Dr. Samuel Wright met with the case of an infant, not more than three years old, who took three drachms of the tincture at once, and suffered only from attempts to cough, some retching and much thirst.[^[344]]

It further appears that in medicinal doses, such as a quarter of a grain, frequently repeated, it is a dangerous poison, unless its effects are carefully watched. For in consequence of accumulation in the system, or gradually increasing action, it produces when long used some very singular and hazardous symptoms; and like mercury, foxglove, and some other poisons, it may be taken long without effect, and at length begin to operate suddenly. The symptoms which it then occasions are sometimes those of irritation; namely, incessant vomiting and purging, acute pain in the stomach, loaded tongue, rapid and extreme emaciation, violent cramps and small frequent pulse. These symptoms may continue many days, and even when subdued to a certain extent, vomiting and cramps are apt to recur for months after.[^[345]] A fatal case of this form of affection has been related by M. Zink, a Swiss physician. His patient, after taking too large doses of iodine for about a month, was seized with restlessness, burning heat of skin, tremors, palpitation, syncope, excessive thirst, a sense of burning along the gullet, frequent purging of bilious and black stools, priapism, and tremulous pulse. The symptoms of local inflammation went off in a few days; but those of general fever continued; and he died after six weeks’ illness.[^[346]] Another fatal case has been described in Rust’s Journal. The leading symptoms were pain in the region of the liver, loss of appetite, emaciation, quartan fever, diarrhœa, excessive weakness; and after the emaciation was far advanced a hardened liver could be felt. The patient appears to have died of exhaustion.[^[347]] From this case, and another of which the appearances after death will be presently noticed, it is not improbable that iodine possesses the power of inflaming the liver.

In another and more common affection, the patient is attacked with tremors, at first slight and confined to the fingers, afterwards violent and extending to the whole muscles of the arms and even of the trunk. At the same time there is excessive and rapidly increasing weakness, a sense of anxiety and sinking, a total suspension of the function of digestion, rapid and extreme muscular emaciation, tendency to fainting, and violent continued palpitation,[^[348]] accompanied sometimes with absorption of the testicles in man, and of the mammæ in females. In the midst of these phenomena the curative powers of the poison over the disease for which it has chiefly been used, namely, goître, are developed. It has been remarked in particular, that the diminution of the goître keeps pace with the diminution of the breasts, though at times either effect has been developed without the other. An instance is related in Rust’s Journal of a female, whose breasts began to sink after she had used iodine for four months; and in four weeks hardly a vestige of them remained; but her goître was not affected.[^[349]] An American physician, Dr. Rivers, has twice noticed barrenness apparently induced by the prolonged use of iodine; and as in these instances the females were young and previously very prolific, but ceased to bear children from the time the iodine was used, his observations seem worthy of attention.[^[350]] Dr. Jahn[^[351]] specifies among the leading effects of the poison when slowly accumulated in the body,—absorption of the fat,—increase of all the excretions,—dinginess of the skin, with frequent clammy sweat,—hurried anxious breathing,—diuresis and an appearance of oil floating in the urine,—increased discharge of fæces, which are unusually bilious, but free of mucus,—increased secretion of semen,—increased menstrual discharge,—swelling of the subcutaneous veins and lividity of the lips,—feebleness of the pulse, with superabundance of serosity in the blood,—impaired digestion and diminished secretion of saliva and mucus. This affection, which, in conformity with the name he has given it, may be termed Iodism [Iodkrankheit], he contrasts with mercurialism, the constitutional effect of the accumulation of mercury in the body; and he considers the former not more unmanageable than the latter. The dose required to produce these effects are very various. Some people appear almost insensible to its action; in one instance, nine hundred and fifty-three grains were taken in daily portions varying from two to eighteen grains, without any bad effect;[^[352]] and I have known an average of four grains daily taken for fifteen months, with the effect only of increasing the appetite. On the other hand, Dr. Gairdner has seen severe symptoms commence when half a grain was taken three times a day for a single week;[^[353]] and Coindet has seen bad effects from thirty drops of the solution of ioduretted hydriodate taken daily for five days.[^[354]]

Iodine and iodide of potassium in medicinal doses have been supposed by Dr. Lawrie to be capable of exciting in certain constitutions an affection resembling cynanche laryngea in its symptoms, consisting of inflammation of the salivary glands, glottis, and other adjacent parts, and proving sometimes fatal.[^[355]] This property is doubtful; but several instances have been published of profuse salivation and soreness of the mouth during a course of iodine; it is apt to cause chronic irritation of the Schneiderian membrane; and some think that it may affect in like manner the bronchial membrane in the lungs.[^[356]]

Morbid Appearances from Iodine.—The only account I have seen of the appearances left in the body after death from slow poisoning with iodine is contained in the essay of Dr. Zink. In a second fatal case which came under his notice he found enlarged abdomen from distension of the intestines with gases, enlargement of the other viscera and serous effusion into the peritonæum; adhesion of the viscera to one another; redness of the intestines, in some places approaching to gangrenous discoloration; redness and excoriation of the peritonæal coat of the stomach, and also of its villous coat; enlargement and pale rose-red coloration of the liver. In the chest serum was found in the sac of the pleura. The gullet was contracted in diameter, and red internally.

On Poisoning with Iodide of Potassium.

To these remarks on iodine a few observations may be added on the iodide of potassium, one of its compounds, which is now generally substituted in medicine for the simple substance. The tests and actions of this poison have been examined by M. Devergie; and more lately its medico-legal chemistry has been investigated by Dr. O’Shaughnessey and Professor Orfila.

It is sold in the shops of various degrees of purity. Pure iodide of potassium is in white crystals, tending to the cubical form, permanent in the air, possessing a faint peculiar odour, and easily soluble in both water and rectified spirit. Another variety has the same form, but possesses an odour of iodine, is often yellowish in colour, and deliquesces slightly in moist air. This contains an excess of iodine, but may be otherwise pure. A third variety is impure. It presents less tendency to assume a crystalline form, is more or less deliquescent, dissolves but partially in alcohol, and when dissolved effervesces with acids. The principal ingredient in this article is carbonate of potass; and sometimes the proportion of iodide is inconsiderable. In one specimen I procured 74·5 per cent. of carbonate of potass, 16 of water, and only 9·5 of iodide of potassium.

In the solid state the iodide of potassium may be known by the effect of strong sulphuric or nitric acid, which turns it brown with effervescence, and when aided by heat disengages violet fumes of iodine.

In solution many tests will detect it, such as chlorine, nitric acid, corrosive sublimate, acetate of lead, protonitrate of mercury, muriate of platinum, and starch with chlorine or nitric acid. Chlorine or nitric acid forms a brown or orange-coloured solution by disengaging iodine. Corrosive sublimate forms a fine carmine-red precipitate, the biniodide of mercury; acetate of lead a fine yellow precipitate, the iodide of lead; protonitrate of mercury a yellow protiodide of mercury, which gradually fades into a dirty brown. Solution of starch, followed by chlorine in solution or in vapour, strikes a deep blue colour, which, if the fluid is sufficiently diluted, disappears on boiling, reappears on sudden cooling, and is permanently removed by a stream of sulphuretted hydrogen gases. Of these tests the most characteristic is starch with chlorine; and it is also extremely delicate. Too much chlorine however bleaches the blue colour away.

In compound mixtures most and sometimes all of these tests are useless. If the mixture is deeply coloured, none will act characteristically. If carbonate of potass be present in such proportion as is often met with in the shops, the tests cannot be trusted to.

Process for Compound Mixtures.—The following method of analysis is applicable to all mixtures, organic and inorganic. Add water, if necessary, and filter; and if the fluid which passes through is tolerably free from colour, test a little of it with solution of starch and chlorine. If the colour is too deep to admit of this trial, or the test on trial does not act, unite the fluid and solid parts and transmit sulphuretted hydrogen to convert any free iodine into hydriodic acid. Drive off the excess of gas, supersaturate with a considerable excess of potass, filter, and evaporate to dryness. Char the residue at a low red heat in a covered crucible; pulverize the charcoaly mass, and exhaust with water. This solution will probably act characteristically with starch and chlorine; but on the whole it is better in the first instance to remove some of the salts by evaporating to dryness, and exhausting the residuum with alcohol. The alcoholic solution contains the hydriodate of potass, with some other salts; and on being evaporated to dryness, a residuum is left, on which, when dissolved in water, the starch and chlorine will act characteristically. No other test is necessary; and frequently no other test will act, on account of co-existing salts.

I have found that a grain of iodide of potassium may thus be easily detected in six ounces of urine, which must be considered a very complicated fluid. In the solution ultimately procured nitrous acid struck a pale brown tint, and on the addition of solution of starch a dark-blue precipitate was formed; which, after being sufficiently diluted, disappeared under ebullition, leaving a colourless fluid. On cooling, no change took place; but on the subsequent addition of a drop of sulphuric acid, the blue colour and precipitation were immediately restored. No other reagent acted characteristically, although there was a sufficient quantity of solution to try the starch test ten times at least.

Dr. O’Shaughnessey has proposed a more complex method by precipitation with chloride of platinum.[^[357]] Professor Orfila says it is sufficient to boil and filter the suspected matter, and to heat first the liquid and then the solid part with solution of chloride, when violet vapours of iodine are disengaged, which may be condensed and subjected to various tests.[^[358]] I have not compared this method with the one I have been in the practice of using; but, notwithstanding the strong assurances of its proposer, its superiority in point of delicacy seems dubious, although no one can deny its simplicity.[^[359]]

Action and Symptoms in Man.—From the experiments of Devergie on animals, iodide of potassium seems to be in large doses an irritant, though not a powerful one. Two drachms in an ounce of water killed a dog in three days with violent vomiting, and signs of irritation were found in the stomach, namely, black extravasated spots and ulcers in the middle of them. A solution injected into the cellular tissue caused only local inflammation. Injected into the jugular vein in the dose of four grains, it produced tetanus and death in a minute and a half.[^[360]] The latter investigations of Dr. Cogswell confirm essentially these results.

Discrepant accounts have been given of the effects of iodide of potassium on man. When first introduced into medicine, it was conceived to be an active poison, not much inferior to iodine itself. Many however have since had an opportunity of observing that it is in general by no means so energetic. Its medicinal doses were gradually raised from one grain to five, ten, twenty grains; and at last Dr. Elliotson gave to not a few patients so much as two, four, or even six drachms daily in divided doses, without observing any remarkable effect.[^[361]] These and other similar observations however were made at a period when the salt used in British practice was much adulterated, often indeed containing eighty or ninety per cent. of impurity; at the same time it does appear that large doses of a pure salt have been occasionally taken with impunity. On the other hand it has evidently in some instances acted with great force. Mr. Alfred Taylor mentions a case, on the authority of Mr. Ericksen, where five grains produced alarming dyspnœa, attended with inflammation of the nostrils and conjunctiva of the eyes.[^[362]] An instance has been published where twelve grains in four doses occasioned shivering, vomiting, purging, general fever, and extreme prostration; and the purging continued for some days.[^[363]] Dr. Moore Neligan informs me he met with the case of an elderly lady in 1841, who, on taking three five-grain doses for two days, while labouring under irregular gout, was seized with severe headache, thirst, and swelling of the face; which symptoms were succeeded in two days by swelling of the tongue, ulceration of the gums, and profuse salivation for a week. Dr. Lawrie says he has known two grains and a half given thrice in one day, followed by great dyspnœa and irritation in the throat; and is even inclined to think that death resulted on two occasions from repeated medicinal doses.[^[364]] It would farther appear from some important researches made in France, that the protracted use of iodide of potassium in small doses with the food may produce serious derangement of the health,—swelling of the face, headache, urgent thirst, inflammation of the throat, violent colic pains, and frequently bloody diarrhœa. A disease characterized by the symptoms now described appeared repeatedly as an epidemic a few years ago in various parts of France, and spread so widely in one parish, that not less than a sixth of the whole population were attacked. After several careful investigations, it seems to have been fully proved that the affection was owing to the use of salt fraudulently adulterated with an impure salt, obtained from kelp after the separation of carbonate of soda, and consequently impregnated with an appreciable proportion of hydriodate of potass.[^[365]]

It is difficult to arrive at any satisfactory conclusions from these statements as to the nature and energy of the action of this salt as a poison. But on the whole it appears to be not in general very active; and the few instances of unusual activity which have occurred may probably be put to the account of idiosyncrasy. The most remarkable of its idiosyncratic effects from medicinal doses are salivation, and a series of symptoms which imitate sometimes catarrh, and sometimes a cold in the head. I do not know any facts to warrant the general statement of M. Devergie that 18 or 30 grains may constitute a fatal dose.[^[366]] The present question is far from being unimportant in a medico-legal point of view. Mr. A. Taylor mentions the heads of a case, very dubious however in its nature, where it was suspected that a single dose of six grains of iodide of potassium had been the occasion of death.[^[367]]

It is important to remember in medico-legal researches, that iodide of potassium may be detected in the blood, liver, spleen, muscles, urine, and other textures and secretions; and especially that it may be found in the urine, when it may no longer exist in the alimentary canal or in vomited matters. These interesting facts have been clearly proved by the researches of Wöhler,[^[368]] Stehberger,[^[369]] O’Shaughnessey,[^[370]] and Dr. Cogswell.[^[371]]

Of Poisoning with Bromine.—This singular substance is not an object of much interest in relation to medical jurisprudence, because it is rare, and only to be met with in the laboratory of the chemist. Hence, although it appears to be a poison of some activity, it scarcely requires to be dwelt on particularly.

It is easily known from all other substances by its fluidity, its great density, which is thrice as great as that of water, its reddish-brown colour by reflected, and blood-red colour by transmitted light, the orange fumes which occupy the upper part of a bottle partly filled with it, and its intensely acrid suffocating vapour, which is so irritating that an incautious inhalation is followed by all the phenomena of severe coryza and catarrh. Its odour, however, apart from its acridity, is very far from being so disagreeable as its discoverer in naming it seems to have imagined. In its properties it bears a close resemblance to chlorine and iodine.

The toxicological effects and medico-legal relations of bromine have been examined by M. Barthez,[^[372]] Dr. Butske,[^[373]] Dr. Dieffenbach,[^[374]] and Dr. M. Glover.[^[375]]

M. Barthez has given the following process for detecting bromine in compound mixtures, such as the contents of the stomach or vomited matter. First separate the fluid matter by filtration, and subject it to the action of chlorine, which will produce a fine orange colour. Should this effect not result, or the change of colour be observed by the deep tint of the fluid, treat the solid matter with solution of caustic potass; filter and add what passes through to the former fluid; evaporate to dryness and char by a red heat; act on the residue with distilled water. The solution contains the bromide of potassium, and is therefore turned orange-red by chlorine. The orange tint, whether struck at once in the fluid part of the mixture, or after carbonization and solution of the residue, is removed by agitation with ether; and the etherial solution of bromine in its turn loses colour when treated with solution of caustic potass, hydro-bromate of potass being again formed.

M. Barthez found, that a solution of twelve grains injected into the jugular vein of a dog, sometimes occasioned immediate tetanus and death; and that the heart was gorged with clotted blood. Sometimes however even seventeen drops did not prove fatal, but produced merely restlessness, difficult breathing, dilated pupil, frequency of the pulse, and sneezing. Dieffenbach remarked similar effects in the rabbit: The animal either died immediately, or soon recovered altogether. In a cat, after the injection of twelve drops of a concentrated solution into its jugular vein, death took place in fifteen minutes; but in another from which a little blood was drawn after the symptoms were fully formed, complete recovery gradually ensued. Butske found a horse suffer so much from mortal prostration immediately after five grains dissolved in two ounces of water were injected into its jugular vein, that he supposed it was about to die; but it quickly revived, and ultimately got quite well. Dr. Glover obtained similar results. When recovery took place, the leading symptoms were panting, sneezing, discharge from the nostrils, rigors and debility.

When introduced into the stomach of dogs, M. Barthez found that twenty drops on a full stomach had no particular effect; that thirty drops occasioned vomiting, and temporary acceleration of the pulse and breathing; and that from forty to sixty drops on an empty stomach brought on violent vomiting, sneezing, cough, dilated pupil and prostration, succeeded in a few hours by languor without any other symptom, and by death in four or five days. In the dead body he remarked numerous little ulcers of the villous coat, some of which had an ash-gray appearance at the bottom, while others were covered with a black slough, easily removed by friction. When the gullet was tied to prevent vomiting, less doses proved more quickly fatal. He likewise observed that the matter vomited in these experiments, even a few minutes after the administration of the poison, had no appearance or odour of bromine; whence it is reasonable to conclude, that, as in the instance of iodine, a chemical change takes place with the aid of certain vital operations, so that the bromine becomes hydrobromic acid.—The experiments of Dr. Butske assign to it more activity as a poison than those now related. For he found that a dog died in a day from taking only five grains dissolved in two ounces of water; and the symptoms were laborious breathing, loud cries, and convulsions. In the dead body he found the stomach internally chequered with bloody extravasation, and filled with bloody mucus, the duodenal mucous membrane universally injected, but the rest of the alimentary canal in a healthy state.—Dr. Glover remarked in such cases, besides the usual symptoms of an irritant action on the stomach, coryza, sneezing, salivation and difficult breathing. Sixty minims killed a cat in seventeen minutes, two fluid drachms a dog in five hours and a half, ten grains a rabbit in five minutes. A dog twice got twenty grains in solution and recovered, but died after a third dose of the same amount. Another got twenty grains in solution every two or three days for a month without injury. In some of these experiments hydrobromic acid was detected in the blood and urine.

Little is yet known of the effects of bromine on man. Butske found that a drop and a half in half an ounce of water produced a sense of heat in the mouth, gullet, and stomach, and subsequently colic pains; and that two drops and a half in an ounce of mucilage excited, in addition to the preceding symptoms, great nausea, hiccup, and increased secretion of mucus. On the other hand M. Fournet, who gave doses gradually increasing from two to sixty drops daily for many weeks, observed that the lowest doses excited itching in the hands and feet, and sometimes colic; that an increase in the quantity caused heat in the chest and nausea; and that forty-five drops occasioned also severe burning and sense of acidity in the stomach, which however were temporary. The appetite was in general rather improved, and the body became more plump.[^[376]]—Bromine appears on the whole to be a pure local irritant. It acts most energetically when most thoroughly dissolved in water.

Hydrobromic acid seems from the experiments of Dr. Glover to be a pure irritant and corrosive, allied in action and energy to hydrochloric acid. The same experimentalist found that bromine of potassium in the dose of forty grains had sometimes little or no effect on dogs when injected into the blood-vessels, while in other instances less doses cause speedy death by paralysing the heart. Barthez observed that half a drachm in solution produced dulness and depression in dogs, but no other bad effect; and that two drachms retained in the stomach by tying the gullet occasioned death in three days with symptoms of irritant poisoning. M. Maillet observed that two ounces of this salt in the form of ointment, administered to a dog by rubbing it over his nose, and letting him lick it off and swallow it, had no effect whatever.[^[377]]

CHAPTER V.
OF POISONING WITH ACETIC ACID.

Acetic acid, although in its ordinary state undoubtedly possessed of little activity as a poison, has nevertheless proved in some circumstances deleterious, and capable of occasioning death even in the human subject. It exists in various forms. The most common is ordinary vinegar, in which it is much diluted. Another common form is the pyroligneous vinegar, pyroligneous acid, or pyroligneous acetic acid, as it is variously called, which when impure has a reddish-brown colour, but when pure is almost or altogether colourless, and the strength of which is much greater than that of common vinegar. What is called proof vinegar has a density about 1005, and contains about four per cent. of concentrated acid. The pyroligneous acid sold in the shops of this town has a density about 1035, and contains about 25 per cent.; but the pyroligneous acid of the London Pharmacopœia is stronger, for its density is 1050, and 100 parts contain about 50 of the strong acid. A third form is the concentrated or pure acetic acid of the apothecary, which is familiarly known as the chief ingredient and menstruum of a common perfume, aromatic vinegar.

Section I.—Of the Tests for Acetic Acid.

In all its forms acetic acid is easily known by its very peculiar odour, together with its acid reaction on litmus. But if farther evidence of its nature be required, it will be requisite to neutralise the fluid suspected to contain it with carbonate of potass, and then to procure the acetate of potass by evaporation. This salt is known by its extreme tendency to deliquesce, and by a concentrated solution in water, yielding, when distilled with sulphuric acid, a fluid possessing the peculiar odour and pungency of concentrated acetic acid.

When in a state of compound admixture with organic substances, such as the contents of the stomach, it has been proved by late researches of Orfila,[^[378]] that this acid may be present in considerable proportion without distinctly reddening litmus. For such mixtures the following process of analysis, devised by the Parisian professor, will be found convenient and effectual. The fluid being put into a retort with a receiver attached, the retort is to be heated in a muriate of lime bath till the residuum be dry. The distilled fluid may then be tested tentatively for sulphuric and muriatic acids; and these being proved to be absent, the acidity and peculiar smell of the liquid will supply strong presumption of the presence of acetic acid. This presumption may be turned to certainty by forming acetate of potass, as already directed for the pure diluted acetic acid.

Orfila has omitted in his paper a serious fallacy to which this, as well as every process for the detection of acetic acid in the contents of the stomach is exposed,—namely, that the natural secretions of the stomach, according to the researches of many physiologists, but more especially in recent times those of Tiedemann and Gmelin in Germany, and those of Leuret and Lassaigne in Paris, frequently contain a small proportion of acetic acid. Hence, the inference in favour of the introduction of acetic acid into the stomach from without, founded on the process related above, is only legitimate when the quantity discovered is considerable.—The medical jurist ought also to keep in mind that vinegar is a common remedy with the vulgar for many diseases, and especially for poisoning.

Section II.—Of the Effects of Acetic Acid on Man and Animals.

In the first edition of this work, it was stated that acetic acid could scarcely be considered a poison. And in illustration, a case was mentioned which fell under my own notice,—that of a gentleman, who during dinner swallowed at a draught about eight ounces of vinegar by mistake for beer, and who nevertheless sustained no harm although he retained it all, and as the only measure of precaution, swallowed after it an equal quantity of port wine. In farther confirmation of what is here mentioned, it may be added, that an ounce of acid equal in strength to the pyroligneous vinegar, has been found by Schubarth of Berlin to produce very little effect when administered to a dog. The animal merely frothed a little at the mouth; cried and became restless for a time; then had one or two attacks of vomiting; and in an hour appeared quite well again.[^[379]] Nay, it has even been found by Pommer of Heilbronn, that a considerable quantity of diluted acetic acid may be injected into the blood without causing any mischief. He injected six drachms of distilled vinegar into the femoral vein of one dog, and an ounce into the jugular vein of another, but observed no effect whatever, except a slight labour of respiration for a short time afterwards.[^[380]]

It appears, however, from some experiments performed by Professor Orfila on occasion of a judicial case to be mentioned presently, that all the forms of acetic acid will prove injurious and even fatal to dogs, if given in sufficient quantity and prevented from being discharged by vomiting. An ounce of pyroligneous vinegar, administered to dogs of middle size, and retained in the stomach by a ligature on the gullet, produces efforts to vomit, evident suffering, prostration of strength, and death in five, seven, or nine hours. An ounce of concentrated acetic acid occasioned death in one hour and a quarter; and four or five ounces of common vinegar proved fatal in ten or fifteen hours. These experiments would make it appear that acetic acid is scarcely less active as an irritant poison than even the mineral acids.[^[381]] They are in some measure confirmed by the prior experiments of Schubarth; who operated, however, with an impure reddish-brown pyroligneous acid, and was led to ascribe its energy to the presence of some empyreumatic oil, because he found, as was already remarked, that a pure acid of equal strength appeared almost inert. From half an ounce to an ounce of the impure acid given to dogs, caused fruitless efforts to vomit, sometimes free vomiting, occasionally great flow of tears, always weakness in the hind-legs, and feeble, irregular pulse, and death either in two days without any new symptom of consequence, or more rapid death in four or five hours, with previous convulsions, and sometimes insensibility.[^[382]] These experiments were made with an acid which neutralized 50 grains of carbonate of lime per ounce, consequently contained at least 50 grains of concentrated acid, or about a tenth of its weight.

To these observations it may be added, that according to the experiments of Hébréart, a small quantity of acetic acid dropped into the windpipe, produces hissing respiration, rattling in the throat, and death in three days from true croup.[^[383]]

In all the preceding experiments distinct evidence was obtained in the dead body of the irritant action of the poison. The stomach contained brownish-black blood, the villous coat was blackish, and the subjacent cellular tissue injected with black blood; sometimes there was an appearance of erosion on the surface of the villous coat; and in the instance of the concentrated acid perforations were found. In the experiments of Hébréart the lining membrane of the windpipe was covered with a fibrinous pseudo-membrane, exactly as after croup.

Although acetic acid in its various forms is daily in the hands of every body, one case only of poisoning with it in the human subject has hitherto been made public. It is described by MM. Orfila and Barruel.[^[384]] A girl was seen in a village near Paris at eleven at night apparently intoxicated. Five hours afterwards she was found lying on the ground in great agony; and after complaining of pain in the stomach and experiencing several attacks of convulsions, she expired. On the subsequent examination of the body considerable lividity was observed on the skin of the depending parts. The back of the tongue was brownish and leathery, and the inner membrane of the gullet blackish-brown, intersected by a fine network of vessels. The stomach presented internally several large, black, firm elevations, owing to the injection of coagulated blood into the submucous cellular tissue; and elsewhere it had a grayish-white tint, with here and there a reddish colour; but the mucous membrane was perfectly entire. The cavity contained above eight ounces of a thick, blackish fluid; and a thicker pulpy matter of the same colour adhered firmly to the villous coat. The intestines were healthy, and so also were the other organs in the belly and chest. The uterus contained a fœtus two months and a half old. The contents of the stomach were subjected to a careful analysis by MM. Orfila and Barruel, who found that they did not contain any appreciable quantity of free sulphuric or muriatic acid, or of any of the common metallic poisons; and by the process of analysis formerly described, they succeeded in separating from the impure mass three drachms of a pure, and tolerably concentrated acetic acid, besides two drachms more from the contents of the intestines. As the residue of the distillation left behind in the retort did not yield any bitter principle to boiling alcohol, so as to countenance the idea of a vegetable alkaloid having been given along with the acetic acid, they inferred that this acid had been swallowed alone; and the experiments of Orfila on dogs, performed for the occasion, induced them to conclude that it was the cause of death.

To these observations it is only farther necessary to add, that the concentrated acid is a powerful irritant and even corrosive when applied externally; which properties are owing to its power of dissolving many of the soft animal solids.[^[385]]

CHAPTER VI.
OF POISONING WITH OXALIC ACID.

The last poison of this order is oxalic acid. It is a substance of very great interest; for it is a poison of great energy, and in this country is in common use for committing suicide, and has been often taken by accident for Epsom salt.

It is certainly ill adapted for the purposes of the murderer; for although it might be easily given to a sick person instead of a laxative salt, yet its real nature would betray itself too soon and too unequivocally for the chief object of the prisoner,—secrecy. Nevertheless, attempts of the kind have been made. At the trial of James Brown for assaulting his wife, held at the Middlesex Autumn Assizes 1827, it was brought out in evidence that he had previously tried to poison her by giving her oxalic acid in gin;[^[386]] and Mr. Alfred Taylor says he is acquainted with two similar cases, where an attempt was made to administer it in tea.[^[387]]

It was first made known as a poison by Mr. Royston in 1814.[^[388]] Its properties have been examined by Dr. A. T. Thomson of London,[^[389]] and Dr. Perey of Lausanne;[^[390]] in 1823, the whole subject of poisoning with oxalic acid in its medico-legal relations was examined by Dr. Coindet of Geneva and myself;[^[391]] and in 1828, another experimental inquiry, which confirms most of the results we obtained, was published by Dr. Pommer of Heilbronn.[^[392]]

Section I.—Of the Tests for Oxalic Acid.

Oxalic acid is commonly in small crystals of the form of flattened six-sided striated prisms, transparent, colourless, free of odour, very acid to the taste, and permanent in the air. Two other common vegetable acids, the citric and tartaric acids, present a totally different crystalline form. In general appearance it greatly resembles the sulphate of magnesia, for which it has been so often and so fatally mistaken. So close, indeed, is the resemblance, that repeatedly, on desiring several persons to point out which was the poison and which the laxative, I have found as many fix on the wrong as on the right parcel. The sulphate of magnesia has of course a very different taste, being strongly bitter. Various plans have been devised for preventing the accident to which this unlucky resemblance has given rise. The best of them imply the use of a safeguard by the patient before he takes his laxative draught. It seems to have escaped the notice of those who have proposed the plans in question, that, if accidents are to be prevented in this manner, by far the simplest and most effectual security will be to let the public know, that a laxative salt ought always to be tasted before being swallowed. Its solubility has been much overrated by some chemists. It does not appear to me soluble in less than eleven parts of water.

In determining the medico-legal tests for oxalic acid, it will be sufficient to consider it in two states,—dissolved in water,—and mixed with the contents of the stomach and intestines or vomited matter. If the substance submitted to examination is in the solid state, the first step is to convert it into a solution.

1. In the form of a pure solution, its nature may be satisfactorily determined by the following process.

The acidity of the fluid is first to be established by its effect on litmus-paper.—A small portion is next to be tested with ammonia, which, if the solution of the acid be sufficiently concentrated, will produce a radiated crystallization, as the oxalate of ammonia formed is much less soluble than oxalic acid itself. This property, according to Dr. O’Shaughnessey, distinguishes it from every other acid.[^[393]] The remainder of the fluid is next to be subjected to the following reagents.

Hydrochlorate of lime causes a white precipitate, the oxalate of lime; which is dissolved on the addition of a drop or two of nitric acid,—and is not dissolved when similarly treated with hydrochloric acid, unless the acid is added in very large proportion.

The easy solubility of the oxalate of lime in nitric acid distinguishes the precipitate from the sulphate of lime, which the present test might throw down from solutions of the sulphates, and which is not soluble in a moderate quantity of nitric acid without the aid of heat. The insolubility of the oxalate of lime in hydrochloric acid on the other hand distinguishes the precipitate from the tartrate, citrate, carbonate and phosphate of lime, which the test might throw down from any solution containing a salt of these acids. The last four precipitates are redissolved by a drop or two of hydrochloric acid; but the oxalate is not taken up till a large quantity of that acid is added.

Sulphate of lime in solution causes a white precipitate with oxalic acid, and not with any other.[^[394]]

Sulphate of copper causes a faint bluish-white, or greenish-white precipitate, which is not redissolved on the addition of a few drops of hydrochloric acid. The precipitate is the oxalate of copper. It is redissolved by a large proportion of hydrochloric acid.

This test does not precipitate the sulphates, hydrochlorates, nitrates, tartrates, citrates. But with the carbonates and phosphates it forms precipitates resembling the oxalate of copper. The oxalate, however, is distinguished from the carbonate and phosphate of copper by not being redissolved on the addition of a few drops of hydrochloric acid.

Nitrate of silver causes a dense, white precipitate, the oxalate of silver; which, when collected on a filter, dried and heated, becomes brown on the edge, then fulminates faintly and is dispersed.

The object of the supplementary test of fulmination is to distinguish the oxalate of silver from the numberless other white precipitates which are thrown down by the nitrate of silver from solutions of other salts. The property of fulmination, which is very characteristic, requires, for security’s sake, a word or two of explanation, in consequence of the effect of heat on the tartrate and citrate of silver. The citrate when heated becomes altogether brown, froths up, and then deflagrates, discharging white fumes and leaving an abundant, ash-gray, coarsely fibrous, crumbly residue, which on the farther application of heat becomes pure white, being then pure silver. The tartrate also becomes brown and froths up, but does not even deflagrate, white fumes are discharged, and there is left behind a botryoidal mass, which, like the residue from the citrate, becomes pure silver when heated to redness. Another distinction between the oxalate and tartrate is that the former continues permanent at the temperature of ebullition, while the latter becomes brown. The preceding process or combination of tests will be amply sufficient for proving the presence of oxalic acid, free or combined, in any fluid, which does not contain animal or vegetable principles.

2. The only important modifications in the analysis rendered necessary by the admixture of organic principles, occur in the case of the contents of the alimentary canal or vomited matters.

Dr. Coindet and I proved, that oxalic acid has not any chemical action with any of the common animal principles except gelatin, which it rapidly dissolves;—and that this solution is of a peculiar kind, not being accompanied with any decomposition, either of the acid or of the gelatin.[^[395]] Consequently oxalic acid, so far as concerns the tissues of the stomach or its ordinary contents, is not altered in chemical form, and remains soluble in water.

In such a solution, however, a variety of soluble principles are contained, which would cause abundant precipitates with two of the tests of the process,—sulphate of copper and nitrate of silver; so that the oxalates of these metals could not possibly be detached in their characteristic forms. The process for a pure solution, therefore, is inapplicable to the mixtures under consideration.

But changes of still greater consequence are effected on the poison by exhibiting antidotes during life. It is now generally known, that the proper antidotes for oxalic acid are magnesia and chalk. Each of these forms an insoluble oxalate; so that if either had been given in sufficient quantity, no oxalic acid will remain in solution, and the proofs of the presence of the poison must be sought for in the solid contents of the stomach or solid matter vomited.

The following process for detecting the poison will apply to all the alterations which it may thus have undergone.

Process for Compound Mixtures.—If chalk or magnesia has not been given as an antidote, the suspected mixture is to be macerated if necessary for a few hours in a little distilled water, then filtered, and the filtered fluid neutralized with carbonate of potass. If on the other hand chalk or magnesia has been given, the mixture is to be left at rest for some time, and the supernatant fluid then removed. This fluid, if not acid, may be thrown away; but if acid, it may be treated as already directed for a suspected mixture, where chalk or magnesia has not obtained entrance. After the removal of the supernatant liquid, pick out as many solid fragments of animal or vegetable matter as possible; and add as much pure water to the insoluble residue as will give the mass a sufficiently thin consistence. Add now to the mixture about a twentieth of its weight of carbonate of potass, and boil gently for two hours, or till the organic matter is all dissolved. While dissolution thus takes place, a double interchange is effected between the elements of the carbonate of potass on the one hand, and those of the earthy oxalate on the other, so that an oxalate of potass will at length exist in solution. The fluid when cold is next to be filtered, then rendered very faintly acidulous with nitric acid, then filtered and rendered very faintly alkaline with carbonate of potass, and filtered a third time. At each of these steps some animal matter will be thrown down.

From this point onwards the process proceeds in the same way, whatever may have been the original form in which the acid existed in the mixture; for the oxalate of lime or magnesia in the second case is converted into oxalate of potass.

Add now the solution of acetate of lead to the fluid as long as any precipitate is formed. Collect the precipitate on a filter, wash it well, and dry it by compression between folds of bibulous paper. Remove this precipitate, which consists of oxalate of lead and organic matter in union with oxide of lead, and rub it up very carefully while damp with a little water in a mortar. Transmit sulphuretted hydrogen gas briskly for an hour, so that the whole white precipitate shall be thoroughly blackened; filter and boil. In this manner is formed a sulphuret of lead, which retains a great deal of animal matter; and the oxalic acid being set free, is found in the solution tolerably pure. Filtration before boiling is an essential point in this step, to prevent animal matter being dissolved by the water from the sulphuret of lead. More animal matter may still be separated by evaporating the liquid to dryness at 212°, keeping it at that temperature for a few minutes, and redissolving and filtering. The solution will now exhibit the properties of oxalic acid.

I have found that when this process was applied to a decoction of an ounce of beef in six ounces of water, with which one grain of anhydrous oxalic acid had been mixed, all the tests acted characteristically on the solution ultimately procured. I have farther found, that when two grains of oxalate of lime, which correspond with one grain of oxalic acid, were mixed with a similar decoction in which some fragments of beef were purposely left to complicate the process, a solution was eventually obtained, which gave with muriate of lime a white precipitate insoluble in a little muriatic acid, with sulphate of copper a greenish-white precipitate also insoluble in a little muriatic acid, and with nitrate of silver a white precipitate which fulminated and was almost all dispersed, but left a little charcoal, owing to its containing a small proportion of animal matter. In a case which lately happened in London, every test acted as here described, except that the oxalate of lime did not fulminate, owing to the presence of organic impurities.[^[396]] In order to try the test of fulmination in such circumstances, it is essential to dry the precipitated oxalate of silver thoroughly before raising the temperature to the point at which fulmination usually occurs.

The process now recommended is both delicate and accurate. An objection has been advanced against it,—that acetate of lead will throw down chloride of lead as well as the oxalate of lead; that both will subsequently be decomposed by the sulphuretted-hydrogen? and that the hydrochloric acid thus brought into the solution with the oxalic acid will be precipitated by the nitrate of silver, and form a mixture of salts which will not fulminate characteristically.[^[397]] This objection is not well founded. Chloride of lead being soluble in thirty parts of temperate water, it will seldom be thrown down from such fluids as occur in medico-legal inquiries; and besides it is easily removed, as I have ascertained, by washing the precipitate with moderate care on the filter.

Professor Orfila has advanced another objection,—that the process will yield all the indications mentioned above, if binoxalate of potash be present, or sorrel-soup, which contains a little of that salt.[^[398]] The objection is valid, were these substances apt to come in the way. But the binoxalate of potash is not put to any medicinal use in Britain, and English cookery does not acknowledge the “soupe à l’oseille.” The process he recommends to meet the difficulty, an important one in France, is the following: 1. Having made a watery solution as above, evaporate nearly to dryness, agitate the residue with cold pure alcohol, repeatedly during a period of several hours; decant the tincture, and repeat this step with more alcohol; evaporate to obtain crystals, if possible; dissolve these again in cold pure alcohol, and crystallize a second time by evaporation. If crystals do not form on first concentrating the alcoholic solution, evaporate it till a pellicle begins to form, agitate the residue with cold pure alcohol, and concentrate again to obtain crystals. Lastly, examine the crystals by the tests for pure oxalic acid. The object of these steps in the process is to separate binoxalate of potass, oxalate of magnesia and oxalate of lime, which, he says, are all either not soluble, or very sparingly so, in absolute alcohol. 2. More oxalic acid may be got by acting with distilled water on the matter left by the action of alcohol, evaporating this watery solution nearly to dryness, agitating the residuum with cold alcohol as before, and so on. 3. The preceding operations may have left oxalate of magnesia and oxalate of lime unacted on by the water among the solids remaining on the filter. The former compound may be dissolved out by cold hydrochloric acid diluted with four times its volume of water; and by an excess of pure carbonate of potass, the oxalate of magnesia in the solution is converted into insoluble carbonate of magnesia and soluble oxalate of potass, from which oxalic acid is to be obtained by a salt of lead and sulphuretted-hydrogen, as explained in my own process. 4. Oxalate of lime, which may still remain, is to be sought for by boiling the residuum of the action of hydrochloric acid with solution of bicarbonate of potash, so as to obtain here also an oxalate of potass in solution. I have not had an opportunity of trying this method. But I find, that, contrary to Orfila’s statement, binoxolate of potass, though sparingly soluble in cold alcohol of the density of 800, is sufficiently so to vitiate the principle on which the process is founded.

Caustic potass must not be used for decomposing oxalate of lime or magnesia, because the pure alkali, as Gay-Lussac has shown, produces oxalic acid in acting on animal substances at a boiling temperature. Carbonate of potass has no such effect.

The discovery of oxalic acid in the form of oxalate of lime in the stomach or vomited matter is exposed to a singular fallacy, if a material quantity of rhubarb has been taken recently before death, or before the discharge of the vomited matter. For according to the researches of M. Henry of Paris, rhubarb root always contains some oxalate of lime, and some samples yield so much as 30 and even 33 per cent.[^[399]]

Section II.—On the Action of Oxalic Acid and the Symptoms it causes in Man.

The action of oxalic acid on the animal economy is very peculiar.

When injected in a state of concentration into the stomach of a dog or cat, it causes exquisite pain, expressed by cries and struggling. In a few minutes this is succeeded by violent efforts to vomit; then by sudden dulness, languor, and great debility; and death soon takes place without a struggle. The period which elapses before death varies from two to twenty minutes, when the dose is considerable,—half an ounce, for example. After death the stomach is found to contain black extravasated blood, exactly like blood acted on by oxalic acid out of the body; the inner coat of the stomach is of a cherry-red colour, with streaks of black granular warty extravasation; and in some places the surface of the coat is very brittle and the subjacent stratum gelatinized, evidently by the chemical action of the poison.[^[400]] If the stomach is examined immediately after death, little corrosion will be found, compared with what is seen if the inspection be delayed a day or two.[^[401]]

Such are the effects of the concentrated acid. When considerably diluted, the phenomena are totally different. When dissolved in twenty parts of water, oxalic acid, like the mineral acids in the same circumstances, cease to corrode; nay it hardly even irritates. But, unlike them, it continues a deadly poison; for it causes death by acting indirectly on the brain, spine, and heart. The symptoms then induced vary with the dose. When the quantity is large, the most prominent symptoms are those of palsy of the heart; and immediately after death that organ is found to have lost its contractility, and to contain arterial blood in its left cavities. When the dose is less the animal perishes after several fits of violent tetanus, which affects the respiratory muscles of the chest in particular, causing spasmodic fixing of the chest and consequent suffocation. When the dose is still less, the spasms are slight or altogether wanting, and death occurs under symptoms of pure narcotism like those caused by opium: the animal appears to sleep away.

This poison acts with violence, and produces nearly the same effects to whatever texture of the body it is applied. It causes death with great rapidity when injected into the sac of the peritonæum, or into that of the pleura; it acts with still greater quickness when injected into a vein; and it also acts when injected into the cellular tissue beneath the skin, but with much less celerity than through any other channel. Eight grains injected into the jugular vein of a dog occasioned almost immediate death: Thirty-three grains injected into the pleura killed another in twelve minutes. The same quantity did not prove fatal, though it caused violent effects, when retained in the stomach by a ligature on the gullet. One hundred and sixty grains injected under the skin of the thigh and belly did not prove fatal for about ten hours. The symptoms were nearly the same in every case.[^[402]]

It is probable from the facts now stated, that oxalic acid, when not sufficiently concentrated to occasion death by the local injury produced, acts on the nervous system through the medium of the blood. Nevertheless it is a remarkable circumstance that it cannot be detected in that fluid. Mention has already been made of an experiment performed by Dr. Coindet and myself (p. [22]), where even after the injection of eight grains of oxalic acid into the femoral vein, and the consequent death of the animal in thirty seconds, none of the poison could be detected in the blood of the iliac vein or vena cava. Similar results have been more lately obtained by Dr. Pommer. In dogs killed by the gradual injection of from five to thirty grains into the femoral vein, he never could detect the poison in the blood of the right side of the heart or great veins, except in the instance of the largest doses, where a little could be detected near the opening in the vein. Dr. Pommer’s experiments likewise agree with those of Dr. Coindet and myself as to the absence of any change in the physical qualities of the blood.[^[403]] When to these circumstances it is added that very small quantities of oxalic acid may be detected in blood, into which it has been introduced immediately after removal from the body by venesection, it appears reasonable to conclude that the poison is quickly decomposed in the blood by vital operations.

According to Orfila, however, it may be detected in the urine, in which crystals of oxalate of lime form on cooling, and more may be obtained on the addition of hydrochlorate of lime. Yet he could not detect any oxalic acid in the liver or spleen.[^[404]]

In man the most prominent symptoms hitherto observed have been those of excessive irritation, because it has been almost always swallowed in a large dose and much concentrated.

It is the most rapid and unerring of all the common poisons. The London Courier contains an inquest on the body of a young man who appears to have survived hardly ten minutes;[^[405]] an equally rapid case of a young lady, who poisoned herself with an ounce, is mentioned in the St. James’s Chronicle;[^[406]] and few of those who have died survived above an hour. This rule, however, is by no means without exception. Mr. Hebb has described a case which did not prove fatal for thirteen hours;[^[407]] Dr. Arrowsmith of Coventry has favoured me with the particulars of a very interesting case which lasted for the same period: and Mr. Frazer has accurately described another, in which, after the patient seemed to be doing tolerably well, an exhausting fever, with dyspepsia and singultus, carried him off in twenty-three days.[^[408]]

Among the fatal cases the smallest dose has been half an ounce; but there can be little doubt that less would be sufficient to cause death. Dr. Babington of Coleraine has published a case where very severe effects were produced by only two scruples.[^[409]]

Very few persons have recovered where the quantity was considerable.

In every instance in which the dose was considerable, and the solution concentrated, the first symptoms have been immediate burning pain in the stomach, and generally also in the throat. But when the dose was small, more particularly if the solution was also rather diluted, the pain has sometimes been slight, or slow in commencing. Mr. Hebb’s patient, who took only half an ounce dissolved in ten parts of water, and diluted it immediately after with copious draughts of water, had not any pain in the belly for six hours.

In general, violent vomiting follows the accession of pain, either immediately, or in a few minutes; and it commonly continues till near death. Some, however, have not vomited at all, even when the acid was strong and in a large dose; and this is still more apt to happen when the poison has been taken much diluted. The man last mentioned did not vomit at all for seven hours, except when emetics were administered. The vomited matter, as in this man’s case, and in that of Mr. Frazer’s patient, is sometimes bloody. Instant discharge of the poison by vomiting does not always save the patient’s life: A woman who swallowed two ounces died in twenty minutes, although she vomited almost immediately after taking the poison.[^[410]]

The tongue and mouth occasionally become inflamed if the case lasts long enough. In an instance of recovery, which happened not long ago in St. Thomas’s Hospital, London, the tongue was red, swollen, tense and tender, the day after the acid was swallowed.[^[411]]

Death commonly takes place so soon, that the bowels are seldom much affected. But when life is prolonged a few hours, they are evidently much irritated. Dr. Arrowsmith’s patient, who lived thirteen hours, had severe pain in the bowels and frequent inclination to go to stool, and Mr. Hebb’s patient, who also lived thirteen hours, had a constant, involuntary discharge of fluid fæces, occasionally mixed with blood. Bloody diarrhœa is very common in dogs.

The signs of depressed circulation are always very striking. In general the pulse fails altogether, it is always very feeble, and the skin is cold and clammy. Contrary to the general fact, however, I once remarked in a dog the pulsation of the heart so strong as to be audible at a distance of several yards.

In some cases nervous symptoms have occurred, but in none so distinctly as in animals that have taken the diluted acid. It should be remarked, however, that few published cases contain good histories of the symptoms; since they commonly come to an end before being seen by the physician. Convulsions appear to have occurred in some instances either at the time of death or soon before it. In the slower cases various nervous affections have been observed. A girl, who swallowed by mistake about two drachms, and did not vomit till emetics were given, complained much at first of pain, but afterwards chiefly of great lassitude and weakness of the limbs, and next morning of numbness and weakness there as well as in the back. This affection was at first so severe that she could hardly walk up stairs; but in a few days she recovered entirely.[^[412]] Analogous effects took place in Mr. Hebb’s patient and in Dr. Arrowsmith’s case. The first thing the former complained of was acute pain in the back, gradually extending down the thighs, occasioning ere long great torture, and continuing almost till the moment of death. Dr. Arrowsmith’s patient had the same symptoms, complained more of the pain shooting down from the loins to the limbs than of the pain in the belly, and was constantly seeking relief in a fresh change of posture. Mr. Frazer’s patient had from an early period a peculiar general numbness, approaching to palsy. Dr. Babington’s patient, who took two scruples by mistake for tartaric acid in an effervescing draught, suffered, after the first twenty-four hours, chiefly from headache, extreme feebleness of the pulse, and a sense of numbness and tingling or pricking in the back and thighs. In a recent case described by Mr. Tapson, which occurred in London, and where it was supposed, but on insufficient grounds,[^[413]] that so much as two ounces had been taken, violent symptoms of irritation in the alimentary canal came on as usual, but soon afterwards a sense as if the hands were dead, loss of consciousness for eight hours, and then lividity, coldness, and almost complete loss of the power of motion in the legs; which symptoms were not entirely removed for fifteen days. In a case related by Mr. Alfred Taylor, where death was caused by seven drachms in fifteen or twenty minutes, there was first violent vomiting, then severe pain in the stomach, and finally clammy perspiration and convulsions, with two or three deep inspirations before death.[^[414]] The effects in this case came very near those generally observed in animals.

In Dr. Arrowsmith’s case two symptoms occurred, which I have not seen mentioned in any other. The first was an eruption or mottled appearance of the skin in circular patches, not unlike the roundish red marks on the arms of stout healthy children, but of a deeper tint. The second was the poisoning and death of leeches applied to the stomach. “They were healthy,” says Dr. Arrowsmith in the notes with which he obligingly furnished me, “small, and fastened immediately. On looking at them in a few minutes I remarked that they did not seem to fill, and on touching one it felt hard and immediately fell off, motionless and dead. The others were all in the same state. They had all bitten and the marks were conspicuous; but they had drawn scarcely any blood. They were applied about six hours after the acid was taken.” This curious fact illustrates the observations formerly quoted from Vernière’s experiments [p. [67]]. It will be observed that the leeches were applied several hours after the poison was swallowed, and in a case in which the acid was largely diluted in the stomach;—so that it might have entered the blood and been diffused throughout the body before the observation was made.

Section III.—Of the Morbid Appearances caused by Oxalic Acid.

The external appearance of the body is commonly natural. In one instance the cellular tissue was distended with gases ten hours after death.[^[415]] Violent marks of irritation have been commonly found in the stomach; and sometimes that organ has been even perforated.[^[416]] It is probable that the extensive destruction of the coats noticed by some authors has taken place in part after death from the action of the acid on the dead tissues.—The usual conjunction of morbid appearances is well described by Mr. Hebb. The mucous coat of the throat and gullet looked as if it had been scalded, and that of the gullet could be easily scratched off. The stomach contained a pint of thick fluid. This is commonly dark, like coffee-grounds, as it contains a good deal of blood. The inner coat of the stomach was pulpy, in many points black, in others red. The inner membrane of the intestines was similarly but less violently affected. The outer coat of both stomach and intestines was inflamed. The lining membrane of the windpipe was also very red.—The appearances have also been excellently described in the case published by Mr. Alfred Taylor. The inside of the gullet was pale, as if boiled, strongly corrugated and brittle, and covering a ramification of vessels filled with consolidated blood. The stomach presented externally numerous vessels in the same state; and its villous coat was pale, soft, brittle, but here and there injected with vessels. The duodenum and part of the jejunum were red, the other intestines natural, the liver, spleen, and kidneys congested. The stomach contained a brownish jelly, in which gelatin was detected, as well as oxalic acid. The blood was fluid every where except in the vessels of the gullet and stomach.[^[417]] The consolidated condition of the blood there was evidently owing to the local action of a strong acid, and is the same with what has been observed in poisoning with the mineral acids.—In Mr. Frazer’s patient the whole villous coat of the stomach was either softened or removed, as well as the inner membrane of the gullet, so that the muscular coat was exposed; and this coat presented a dark gangrenous-like appearance, being much thickened and highly injected.

Although these signs of violent irritation are commonly present, it must at the same time be observed, that some cases have occurred where the stomach and intestines were quite healthy. In a girl who died about thirty minutes after swallowing an ounce of the acid, no morbid appearance whatsoever was to be seen in any part of the alimentary canal.[^[418]] In the case of a girl, described by Mr. Anderson, where death took place in twenty minutes, there was no appearance but contraction of the rugæ of the gullet and stomach, one spot of extravasation in the latter and doubtful softening of its villous coat.[^[419]]

The state of the other organs of the body has not been taken notice of in published cases. In several instances, as in Mr. Taylor’s case, the blood in the veins of the stomach is described as having been black and as it were charred; probably by the chemical action of the acid after death.

Section IV.—Of the Treatment of Poisoning with Oxalic Acid.

The chief part of the treatment of this kind of poisoning is obvious. On account of its dreadful rapidity, remedies cannot be of material use unless they are resorted to immediately after the acid has been swallowed. Emetics may be given, if vomiting is not already free; but time should never be lost in administering them if an antidote is at hand. In particular it is necessary to avoid giving warm water with a view to accelerate vomiting, unless it is given very largely; for moderate dilution will promote the entrance of the poison into the blood, if it has not the effect of immediately expelling it.

The principal object of the practitioner should be to administer as speedily as possible large doses of magnesia or chalk suspended in water. Chalk has been given with great advantage in several cases,[^[420]] and magnesia has also been of service.[^[421]] As no time should be lost, the plaster of the apartment may be resorted to, when chalk or magnesia is not at hand. These substances not only neutralize the acid so as to take away its corrosive power, but likewise render it insoluble, so as to prevent it from entering the blood. There appears no particular reason for using the stomach-pump when antidotes are at hand. But fashion seems to have authorised the employment of this instrument for every kind of poison.[^[422]] Alkalis are inadmissible. As might be inferred from the general statements formerly made on the effect of chemical changes on poisons [p. [28]], the alkalis, as they form only soluble salts, will not deprive oxalic acid of its remote or indirect action; and instances are not wanting of their inutility in actual practice.

Oxalic acid is one of the poisons alluded to under the head of General Poisoning,—of whose operation distinct evidence may sometimes (though certainly not always) be found in the symptoms. If a person, immediately after swallowing a solution of a crystalline salt, which tasted purely and strongly acid, is attacked with burning in the throat, then with burning in the stomach, vomiting particularly of bloody matter, imperceptible pulse and excessive languor, and dies in half an hour, or still more in twenty, fifteen, or ten minutes, I do not know any fallacy which can interfere with the conclusion, that oxalic acid was the cause of death. No parallel disease begins so abruptly and terminates so soon; and no other crystalline poison has the same effects.

Poisoning with the Oxalates.—Oxalic acid is one of the best examples of a poison that acts through all its soluble chemical combinations. Dr. Coindet and I found that the oxalates of potash and ammonia are little inferior in energy to the acid. They do not corrode, indeed, and scarcely ever irritate; but they produce tetanus and coma, like the diluted acid. Half a drachm of oxalic acid neutralized with potass will kill a rabbit in seventeen minutes; ninety grains of neutral oxalate of ammonia will kill a strong cat in nine minutes.[^[423]] The binoxalate of potash, the most familiar of the salts of oxalic acid, was not tried by us. But the preceding facts would leave little doubt of its being a poison.

Since the last edition of this work was published several cases have occurred which amply confirm the results of experimental inquiry. In Dr. Babington’s case alluded to above, the greater part of the oxalic acid had been neutralized by bicarbonate of soda [p. [176]].—Mr. Tripier has communicated the particulars of a case in which half an ounce of the binoxalate of potash was taken by mistake for bitartrate of potash in hot water, and caused death in eight minutes, after an attack of violent pain and convulsions.[^[424]]—A young woman at Bordeaux was attacked with frequent vomiting after a dose of a drachm and a half of the same salt dissolved in a ptisane. Next morning a similar dose caused bloody vomiting and acute pain at the pit of the stomach; and a third dose the following day excited delirium, more violent vomiting, and death in the course of an hour.[^[425]]—A girl in London swallowed about an ounce of the same salt dissolved in hot water. Sickness and faintness ensued, with imperceptible pulse, cold, clammy skin, rigors, scalding of the mouth and throat, pain in the back, soreness of the eyes, redness of the conjunctivæ, and dilatation of the pupils. Afterwards there was reaction, with a full frequent pulse, hot skin, flushed countenance, headache, thirst, and tenderness of the abdomen. She recovered under the use of chalk, external heat, ether and opium draughts, leeches and sinapisms to the belly, and carbonate of ammonia.[^[426]]

No account has yet been published of the morbid appearances in man.

The proper antidote is sulphate of magnesia. Failing this, weak milk of lime may be given with advantage.

Appendix on Tartaric and Citric Acid.—These two acids may be taken in considerable quantities without injury. Dr. Coindet and I gave a drachm of each in solution to cats, without observing that the animals suffered any inconvenience.[^[427]] Dr. Sibbald, a surgeon of this place, has informed me of an instance in which a patient of his took in twenty-four hours six drachms of tartaric acid, having by mistake omitted the carbonate of potass sent along with the acid to make effervescing draughts; and yet he did not suffer any more inconvenience then the cats on which Dr. Coindet and I experimented.

Pommer, however, found that tartaric acid is scarcely less active than oxalic acid when injected into the blood. When fifteen grains dissolved in half an ounce of water were injected into the femoral vein of a dog in four doses, difficult breathing and discharge of fæces and urine were produced after each operation, and death speedily ensued without any other particular symptom. As in the instance of oxalic acid, the blood in the great veins was not apparently changed in any of its physical qualities. The heart continued contractile long after death, while in the case of oxalic acid its contractility was suddenly extinguished.[^[428]]

CHAPTER VII.
OF THE ALKALIS AND ALKALINE SALTS.

The second order of the class of irritants comprehends the alkalis, some of the alkaline salts, and lime. The species which it includes are little allied to one another except in chemical composition; and in particular they are little allied in physiological properties. It appears impossible, however, to make a better arrangement than that proposed by Orfila, which will therefore be here followed.

Most of the poisons of the second order are powerful local irritants. Some of them likewise act indirectly on distant organs; and a few are more distinguished by their remote than by their local effects. This order may be conveniently divided into two groups,—the one embracing the two fixed alkalis with their carbonates, nitrates, and chlorides, and also lime,—the other ammonia, with its salts, and likewise the alkaline sulphurets.

The action of the first group is purely irritant and strictly local. When concentrated, the fixed alkalis and their carbonates produce chemical decomposition, softening the animal tissues, and reducing them eventually to a pulpy mass; which change depends on their possessing the power, as chemical agents, of dissolving almost all the soft solids of the body. When much diluted, they produce inflammation, without corroding the textures; and it does not appear that they are even then absorbed in such quantity as to prove injurious to any remote organ. The action of the alkaline nitrates and of lime is that of irritants only; at least their chemical action is obscure and feeble.

Of the Fixed Alkalis and their Carbonates.

Section I.—Of their Tests.

Potass in its caustic state, as usually met with in the shops, forms little gray-coloured cylinders or cakes which have a radiated, crystalline fracture, and an excessively acrid caustic taste, and feel soapy if touched with the wet finger. It deliquesces rapidly in moist air, and then attracts carbonic acid from the atmosphere. It is easily fused by heat, and is exceedingly soluble in water. The solution has a strong alkaline reaction on vegetable colours, restoring reddened litmus to blue, turning syrup of violets or infusion or red cabbage to green, and rendering infusion of turmeric brown. It is distinguished from the alkaline earths when in solution, by not precipitating with carbonic or sulphuric acid, and from soda by the tests to be presently mentioned for its carbonate.

Carbonate of potash [subcarbonate, salt of tartar], is usually sold, when pure, in small white grains, formed by melting the salt and stirring it rapidly as it cools. In its impure state it is called in this country potashes, and when somewhat purified, pearl ash. It has then a mixed grayish, yellowish, or bluish colour, and is sold in crumbly lumps of various sizes. In every state it is deliquescent and very caustic. It cannot be crystallized. It gives out carbonic acid gas with the addition of any stronger acid, such as sulphuric, muriatic, or acetic acid. Its solution precipitates yellow with the chloride of platinum, gives a crystalline precipitate with perchloric acid, when the salt forms not less than a fortieth or fiftieth part,—is similarly acted on by a considerable excess of tartaric acid, if the salt constitute about a thirtieth of the fluid,—and yields with the soluble salts of baryta a white precipitate soluble in nitric acid.

Soda resembles potass closely in chemical as well as physiological properties; and the carbonate bears the same resemblance to the carbonate of potass. The chief differences are the following. The carbonate of soda is easily crystallized, and effloresces on exposure to the air. A solution in twenty parts of water yields no precipitate with either perchloric acid or an excess of tartaric acid, because there is no sparingly soluble perchlorate or bitartrate, as in the case of potash. Its solution is precipitated by antimoniate of potash, because the antimoniate of soda is very sparingly soluble. All its salts remain unaffected by the chloride of platinum, because their base cannot form like potass an insoluble triple salt with the reagent. The acetate of soda is permanent in the air, while the acetate of potass is one of the most deliquescent salts known. In trying this last test, which is very characteristic, care must be taken to avoid an excess of acid in the acetate of soda by expelling it at a temperature of 212°, otherwise the salt is as deliquescent as the acetate of potass.—Another difference is, that the chloride of sodium, being nearly as soluble in temperate as in boiling water, crystallizes with difficulty and but sparingly by cooling a concentrated boiling solution; while the chloride of potassium is much more soluble in hot than in cold water, and crystallizes easily and abundantly when a concentrated boiling solution is cooled down.

Process for Potash and its Carbonate in Organic Mixtures.—The following method has been lately recommended for the detection of potash and its carbonate in complex organic mixtures. Ascertain that the mixture is alkaline in its action on litmus-paper and turmeric-paper, and that it is not ammoniacal in odour. Distil to one-third; ascertain that it has still an alkaline reaction, and evaporate to dryness in a porcelain basin. Agitate the residue, when cold, with absolute alcohol; boil, pour off the liquor, and filter it while hot. Repeat this with the residuum and more alcohol. Distil off most of the alcohol, and evaporate to dryness. Raise the heat to char the residuum, continue the heat as long as vapours come off, remove the charcoaly matter, and incinerate it for forty-five minutes in a silver crucible. Try to separate potash from what remains by means of absolute alcohol; and if this do not succeed, remove carbonate of potash by boiling water. In either case search for potash by litmus-paper, turmeric-paper, chloride of platinum, and perchloric acid.[^[429]]

The conclusiveness of this process depends upon the fact, that absolute alcohol cannot dissolve from solid organic substances such a proportion of lactate, tartrate, acetate, sulphate, or phosphate of potash, or chloride of potassium, as to be acted on by chloride of platinum or perchloric acid.[^[430]]—It is to be observed that carbonate of potash singly is insoluble in absolute alcohol; but it becomes soluble in that fluid, when it is conjoined with various organic matters. Hence it is that this process, intended fundamentally for caustic potash alone, is applicable to carbonate of potash also.

Process for Soda and its Carbonate in Organic Mixtures.—These substances may be separated by the method just described for potash. If the alcoholic solution of the extract of the suspected matter be alkaline in its action on litmus, and be afterwards found to contain soda or its carbonate, the evidence of these substances having been derived from without is satisfactory, because the carbonate of soda contained in many animal matters cannot be so detached. But if no indications of the presence of soda be thus obtained, it is not enough that soda be found in the alcoholic solution of the incinerated alcoholic extract, because the natural carbonate of soda of animal matter may be separated in that manner.[^[431]]

Section II.—Of the Action of the fixed Alkalis, and the Symptoms they cause in Man.

The action of the two fixed alkalis and their carbonates on the animal system is so nearly the same, that the facts which have been ascertained in respect to one of them will apply to all the rest. The operation of potass and its carbonate has been carefully investigated by Professor Orfila,[^[432]] and by M. Bretonneau of Tours.[^[433]]

When caustic potass is injected in minute portions into the veins, it instantly coagulates the blood. Five grains, according to Orfila, will in this way kill a dog in two minutes. But when small doses either of potash itself, or its carbonate, or indeed any of its salts are used, Mr. Blake found, that without coagulating the blood, they arrested the action of the heart in ten seconds, if injected into the jugular vein; and that when they were injected into the carotid artery, they occasioned in four seconds signs of great obstruction in the capillary circulation, and arrestment of the heart’s action in thirty-five minutes, through means of this effect. Next to the salts of baryta he thought the potash salts the most powerful on the heart’s action of all those he tried.[^[434]] When introduced into the stomach potash acts powerfully as an irritant, and generally corrodes the coats of that organ. Thirty-two grains given by Orfila to a dog caused pain in the gullet, violent vomiting, much anguish, restlessness, and death on the third day. On dissection he found the inner coat of the gullet and stomach black and red; and near the pylorus there was a perforation three-quarters of an inch wide, and surrounded by a hard, elevated margin. The observations of Bretonneau are in some respects different. When potass was swallowed by dogs in the dose of 40 grains, he found that the animals, after suffering for some time from violent vomiting, always died sooner or later of wasting and exhaustion; and that the action of the poison was confined chiefly to the gullet, which was extensively destroyed and ulcerated on its inner surface. But when the gullet was defended by the potass being passed at once into the stomach in a caustic holder, larger doses, even several times repeated, did not prove fatal. The usual violent symptoms of irritation prevailed for two or three days; but on these subsiding, the animals rapidly recovered their appetite and playfulness, appearing in fact to be restored to perfect health. Yet there could be no doubt that the stomach all the while was severely injured; for in some of the animals, which were strangled for the sake of examination several weeks after they took the poison, the villous coat was found extensively removed, and even the muscular and peritonæal coats were here and there destroyed and cicatrized. Bretonneau farther adds, that ten or fifteen grains introduced into the rectum caused death sooner than three times as much given by the mouth.

The carbonate of potass possesses properties similar in kind, but inferior in degree to those of the caustic alkali. Two drachms given by Orfila to a dog killed it in twenty-five minutes, violent vomiting and great agony having preceded death. The stomach was universally of a deep-red colour on its inner surface.

Potash and its carbonate are absorbed in the course of their action, and may be detected by Orfila’s process in the liver, kidneys, and urine.[^[435]]

The actions of soda and its carbonate seem on the whole the same with those of potash; but they are not so energetic. In one respect however soda and its salts differ most materially from those of potash. For while the latter, when admitted directly into a vein, act by arresting the action of the heart, soda and its salts, according to the inquiries of Mr. Blake, have no such effect, but cause death by obstructing the circulation of the pulmonary capillaries, and preventing the return of blood from the lungs to the left side of the heart. This conclusion seems to flow from the following facts. The respiration becomes in a few seconds laborious and soon ceases, whilst the heart continues to beat vigorously: arterial pressure is greatly reduced, while venous pressure is much increased owing to accumulation of blood in the right side of the heart: after death the lungs are found congested and often full of froth: and the heart continues contractile, very turgid in the right side, but quite empty of blood in its left cavities.[^[436]]

Poisoning with the caustic alkalis is rare. In 1842, a lady suffering from inflammation of the bowels took an ounce of solution of potass by mistake for kali-water, or a solution of bicarbonate of potash surcharged with carbonic acid. She suffered severely at the time, and died in a fortnight, probably of the conjunct effects of her disease and the poison.[^[437]] This is the only case I have found in print of poisoning with a caustic alkali. But the effects of their carbonates have been several times witnessed, and appear to resemble closely those of the concentrated mineral acids.

The symptoms are in the first instance an acrid burning taste, and rapid destruction of the lining membrane of the mouth; then burning and often constriction in the throat and gullet, with difficult and painful deglutition; violent vomiting, often sanguinolent, and tinging vegetable blues green; next acute pain in the stomach and tenderness of the whole belly; subsequently cold sweats, excessive weakness, hiccup, tremors and twitches of the extremities; and ere long violent colic pains, with purging of bloody stools and dark membranous flakes. So far the symptoms are nearly the same in all cases; but in their subsequent course several varieties may be noticed.

In the worst form of poisoning death ensues at an early period, for example within twenty-four hours, nay even before time enough has elapsed for diarrhœa to begin. A case of this kind, which has been very well described by Mr. Dewar of Dunfermline, and which arose from the patient, a boy, having accidentally swallowed about three ounces of a strong solution of carbonate of potass, proved fatal in twelve hours only.[^[438]] Here death was owing to the general system or some vital organ being affected through sympathy by the injury sustained by the alimentary canal.

In the mildest form, as in a case related by Plenck[^[439]] of a man who swallowed an ounce of the carbonate of potass, the symptoms represent pretty nearly an attack of acute gastritis when followed by recovery,—the effects on man being then analogous to those observed by Bretonneau in animals, when the poison was introduced into the stomach without touching the gullet.

But a more common form than either of the preceding is one, similar to the chronic form of poisoning with the mineral acids, in which constant vomiting of food and drink, incessant discharge of fluid, sanguinolent stools, difficulty of swallowing, burning pain from the mouth to the anus, and rapid emaciation, continue for weeks or even months before the patient’s strength is exhausted; and where death is evidently owing to starvation, the alimentary canal being no longer capable of assimilating food. Two characteristic examples of this singular affection have been recorded in the Medical Repository,[^[440]] and a third, of which the event has not been mentioned, but which would in all likelihood end fatally, has been communicated by M. Jules Cloquet to Orfila.[^[441]] Of the two first cases, which were caused by half an ounce of carbonate of potass having been taken in solution by mistake for a laxative salt, one proved fatal in little more than a month, the other three weeks afterwards. In Cloquet’s case, at the end of the sixth week the membrane of the mouth was regenerated; but the gullet continued to discharge pus, and the stools were purulent and bloody.

Another form perhaps equally common with that just described, and not less certainly fatal, commences like the rest with violent symptoms of irritation in the mouth, gullet, and stomach; but the bowels are not affected, and by and by it becomes apparent that the stomach is little injured; dysphagia or even complete inability to swallow, burning pain and constriction in the gullet, hawking and coughing of tough, leathery flakes, are then the leading symptoms; at length the case becomes one of stricture of the œsophagus with or without ulceration; the bougie gives only temporary relief, and the patient eventually expires either of mere starvation, or of that combined with an exhausting fever. Mr. Dewar has related a very striking example of this form of poisoning with the alkalis.[^[442]] His patient, after the first violent symptoms had exhausted themselves, which took place in sixteen or eighteen hours, suffered little for four or five days till the sloughs began to separate from the lining membrane of the mouth, throat, and gullet. The affection of the gullet then became gradually predominant, and terminated in stricture, of which she appears to have been several times so much relieved as to have been thought in a fair way of recovery. After repeatedly disappointing Mr. Dewar’s hopes of a successful issue by her intemperance in the use of spirituous liquors, she died of starvation about four months after swallowing the poison. Sir Charles Bell has noticed three parallel cases, and has given delineations of the appearance in the gullet of two of them.[^[443]] One of his patients did not die till twenty years after swallowing the poison, which in this instance was soap-less; yet he does not hesitate to ascribe the stricture to that cause, and says death arose purely from starvation.

The carbonate of soda, though a salt in very common use, has not hitherto been the cause of accident, which has found its way into print. It is plainly much less actively corrosive than carbonate of potass, and is therefore probably in every sense less energetic.

Section III.—Of the Morbid Appearances caused by the fixed Alkalis.

The morbid appearances caused by potass, soda, and their carbonates differ with the nature of the case.

In the boy who died in twelve hours Mr. Dewar found the inner membrane of the throat and gullet almost entirely disorganized and reduced to a pulp, with blood extravasated between it and the muscular coat. The inner coat of the stomach was red, in two round patches destroyed, and the patches covered with a clot of blood;—its outer coat, as well as all the other abdominal viscera, was sound.

In the two chronic cases mentioned in the Medical Repository the mischief was much more general, the whole peritonæum being condensed, the omentum dark and turgid, the intestines glued together by lymph, the external coats of the stomach thick, the villous coat almost all destroyed, what remained of it red and near the pylorus ulcerated, and the pyloric orifice of the stomach plugged up with lymph so as barely to admit a small probe.

In Mr. Dewar’s patient who died of stricture of the gullet the intestines were sound, the inner surface of the stomach red especially towards the cardia, the inner and muscular coats of the gullet thickened and firmly incorporated together by effused lymph, the inner coat here and there wanting, the passage of the gullet every where contracted, and to such a degree about two inches above the cardia as hardly to pass a common probe. In Sir C. Bell’s cases the appearances were similar.

Orfila says he is led to conclude from a great number of facts that of all corrosive poisons potass is the one which most frequently perforates the stomach.[^[444]] This appearance, however, has not been mentioned in any case of poisoning in the human subject.

Section IV.—Of the Treatment of Poisoning with the fixed Alkalis.

In the treatment of poisoning with the alkalis the first object is evidently to neutralize the poison. This may be done either with a weak acid, or with oil. Of the acids the acetic in the form of vinegar is most generally recommended, as it is not itself injurious. A successful case in very unpromising circumstances, where two ounces and a half of carbonate of potash had been taken by mistake for cream of tartar, and where the antidote was not administered for half an hour, has been related by M. Liégard of Caen. Great relief was experienced to the burning in the throat and stomach, the chilliness, difficult breathing, and frequent efforts to vomit, which were the first symptoms; and after repeated alternations of collapse and reaction, convalescence was established in eight days.[^[445]]—M. Chereau thinks that for the mineral alkalis and their carbonates fixed oil is a preferable antidote to vinegar; and he has given the heads of two cases of poisoning with large doses of carbonate of potass, in which the free employment of almond oil prevented the usual fatal consequences. It appears to act partly by rendering the vomiting free and easy, partly by converting the alkali into a soap. It must be given in large quantity, several pounds being commonly required.[^[446]] For the subsequent treatment the reader may consult the paper of Mr. Dewar, which contains many useful hints on the management of the most complex description of cases.

CHAPTER VIII.
OF POISONING WITH NITRATE OF POTASS.

The nitrate of potass [nitre, saltpetre, sal-prunelle], is a dangerous poison. It has been often mistaken for the saline laxatives, especially the sulphate of soda, and has thus been the source of fatal accidents.

Section I.—Of the Chemical Tests for Nitrate of Potass.

It exists in commerce and the arts in two forms, fused and crystallized. The fused nitre [sal-prunelle] is sold in little button-shaped masses, spheres of the size of musket-balls, or larger circular cakes, of a snow-white tint. The crystallized salt [sal-petre] is sold in whitish, sulcated crystals, which are often regular and large. They are six-sided prisms, more or lest flattened, and terminated by two converging planes. In both forms nitre has a peculiar, cool, but sharp taste.

Its chemical properties are characteristic. In the solid form, it animates the combustion of burning fuel, and yields nitrous fumes when heated with strong sulphuric acid. In solution it is precipitated yellow by the chloride of platinum, and yields, when not greatly diluted, a crystalline precipitate with perchloric acid. The crude salt of commerce contains chloride of sodium; and hence the odour disengaged by sulphuric acid may be mixed with that of chlorine or hydrochloric acid gas. When mixed with any vegetable or animal infusion by which it is coloured, crystals may sometimes be easily procured in a state of sufficient purity by filtration and evaporation. But if not, then the same process must be resorted to with that formerly recommended for nitric acid (p. [143]), the first step of neutralization with potass being of course dispensed with.—A process nearly the same with this has been suggested by M. Kramer of Milan. He proposes to free the liquid in part of animal matter by adding acetate of lead, transmitting sulphuretted-hydrogen through the filtered fluid to remove any excess of lead, boiling the fluid after another filtration, and then proceeding with acetate of silver to remove chlorides, as in the process I have adopted. In this way he found nitre even in the blood.[^[447]]

Section II.—Of the Action of Nitrate of Potass and its Symptoms in Man.

This substance forms an exception to the general law formerly laid down with regard to the effect of chemical neutralization on the local irritants. Both its acid and its alkali are simple irritants; yet the compound salt, though certainly much inferior in power, is still energetic. Nay, the experiment of Orfila and the particulars of some recently published cases tend even to prove, that the action of its alkali and acid is materially altered in kind by their combination with one another; for, besides inflaming the part to which it is applied, nitre has at times produced symptoms of a secondary disorder of the brain and nerves.

The experiments of Orfila upon dogs show that on these animals it has a twofold action, the one irritating, the other narcotic. He found that an ounce and a half killed a dog in ninety minutes when the gullet was tied, and a drachm another in twenty-nine hours: that death was preceded by giddiness, slight convulsions, dilated pupil, insensibility and palsy; that after death the stomach was externally livid, internally reddish-black, and the heart filled in its left cavities with florid blood; that when the gullet was not tied the animals recovered after several attacks of vomiting, and general indisposition for twenty-four hours; and that when the salt was applied externally to a wound it excited violent inflammation, passing on to gangrene, but without any symptom which indicated a remote or indirect operation.[^[448]] Mr. Blake found that this salt, when injected into the veins of a dog in the dose of fifteen grains dissolved in twenty-four parts of water, causes sudden depression and arrestment of the action of the heart, and death in less than a minute; but that, like other salts of potash, it has no influence on the capillaries of the lungs, though a powerful effect in obstructing the systemic capillary system.[^[449]]—When taken in the ordinary way, it is absorbed in the course of its action, and has been detected both in the blood and the urine by Kramer of Milan.[^[450]]

As to its effects on man, it must first be observed, that considerable doses are necessary to cause serious mischief. In the quantity of one, two, or three scruples, it is given medicinally several times a day without injury; and Dr. Alexander found by experiments on himself, that an ounce and a half, if largely diluted, might thus be safely administered in the course of twenty-four hours.[^[451]] Sometimes, too, even large single doses have been swallowed with impunity. A gentleman of my acquaintance once took nearly an ounce by mistake for Glauber’s salt, and retained it above a quarter of an hour: nevertheless, except several attacks of vomiting, no unpleasant symptom was induced. M. Tourtelle has even related an instance where two ounces were retained altogether and caused only moderate griping, with considerable purging and flow of urine.[^[452]] Resting on such facts as these Tourtelle, with some physicians in more recent times,[^[453]] has maintained that nitre is not a worse poison than other saline laxatives; and some practitioners of the present day have consequently ventured to administer it for the cure of diseases, in the quantity of half an ounce in one dose.[^[454]] It is not easy to say, why these large doses are at times borne by the stomach without injury,—whether the cause is idiosyncrasy, or a constitutional insensibility engendered by disease, or some difference in the mode of administering the salt. But at all events, the facts which follow will leave no doubt that in general it is a dangerous and rapid poison in the dose of an ounce.

Dr. Alexander found that, in the quantity of a drachm or a drachm and a half, recently dissolved in four ounces of water, and repeated every ninety minutes, the third or fourth dose caused chilliness and stinging pains in the stomach and over the whole body; and these sensations became so severe with the fourth dose, that he considered it unsafe to attempt a fifth.[^[455]]

Two cases which were actually fatal have been described in the Journal de Médecine for 1787, the one caused by one ounce, the other by an ounce and a half. In the latter the symptoms were those of the most violent cholera, and the patient died in two days and a half;[^[456]] in the former death took place in three hours only, and in addition to the symptoms remarked in the other there were convulsions and twisting of the mouth.[^[457]] In both the pulse failed at the wrist, and a great tendency to fainting prevailed for some time before death. Dr. Geoghegan has communicated to Mr. Taylor a case where an ounce and a half taken by mistake caused severe pain in the stomach, vomiting, and death in two hours.[^[458]]

Similar effects have been remarked in several cases which have been followed by recovery. A woman in the second month of pregnancy, immediately after taking a handful of nitre in solution, was attacked with pain in the stomach, swelling of the whole body and general pains; she then miscarried, and afterwards had the usual symptoms of gastritis and dysentery, united with great giddiness, ringing in the ears, general tremors and excessive chilliness. She seems to have made a narrow escape, as for three days the discharges by stool were profuse, and composed chiefly of blood and membranous flakes.[^[459]] Dr. Falconer has related another instance, where also the patient’s life seems to have been in great danger. The quantity taken was two ounces, and it was swallowed in half a pint of warm water by mistake instead of a laxative salt. Violent pain in the belly was immediately produced, in half an hour frequent vomiting, and in three hours a discharge of about a quart of blood from the stomach. After the administration of gruel and butter the symptoms began to subside; but they receded slowly; and even six months afterwards the man, though otherwise in good health, had frequent pain in the stomach and flatulence.[^[460]] In the case of a female in the second month of pregnancy, described by Dr. Butter, miscarriage did not take place, although the symptoms were very violent and lasting. The quantity taken was two ounces. The symptoms were first bloody vomiting, afterwards dysentery, which continued seven days; and on the tenth day a nervous affection supervened exactly like chorea, and of two months’ duration.[^[461]] The effects of the poison in the latter period of this woman’s illness tend to establish the existence of a secondary operation on the nervous system. But this kind of action is more strongly pointed out by the following cases. Three puerperal women in the Obstetric Hospital of Pavia got each an ounce of nitre by mistake for sulphate of magnesia. Two, who vomited immediately, did not suffer. The third, who retained the salt fifteen minutes, had pain in the stomach and vomiting, followed by paleness of the countenance, stiffness of the jaw, some stupor, and convulsive movements of the limbs; which symptoms continued till next day, when she gradually recovered.[^[462]] A German physician, Dr. Geiseler, met with an instance, in which the only disorder produced appeared to depend on derangement of the cerebral functions. A woman, after swallowing an ounce of nitre instead of Glauber’s salt, lost the use of speech and the power of voluntary motion, then became insensible, and was attacked with tetanic spasms. This state lasted till next day, when some amelioration was brought about by copious sweating. It was not, however, till eight days after, that she recovered her speech, or the entire use of her mental faculties; and the palsy of the limbs continued two months.[^[463]] Her case resembles the account given by Orfila of the effects of nitre on animals.

Section III.—Of the Morbid Appearances caused by Nitrate of Potass.

The morbid appearances observed in man are solely those of violent inflammation of the stomach and intestines. In Laflize’s case, which proved fatal in three hours, the stomach was distended, and the contents deeply tinged with blood; its peritonæal coat of a dark-red colour mottled with black spots; its villous coat very much inflamed and detached in several places. The liquid contents gave satisfactory evidence of nitre having been swallowed; for a portion evaporated to dryness deflagrated with burning charcoal. In Souville’s patient, who lived sixty hours, the stomach was every where red, in many places checkered with black spots, and at the centre of one of these spots the stomach was perforated by a small aperture. The whole intestinal canal was also red. In Dr. Geoghegan’s case, the stomach contained bloody mucus, and its villous coat was brownish-red, and here and there detached. He could not detect any nitre in it.

CHAPTER IX.
OF POISONING WITH THE ALKALINE AND EARTHY CHLORIDES.

There can be little doubt that the chlorides of soda, potass, and lime are active poisons; but the first two have alone been hitherto carefully investigated by physiological experiments.

The two alkaline chlorides are usually seen in the form of colourless solutions. That of potass is little known in this country; but that of soda is familiar to all in the shape of Fincham’s chloride of soda or bleaching liquid. The chloride of lime, which is best known of them all, is usually in the form of a dry powder, deliquescent, and acrid, commonly termed bleaching powder. All these substances are easily known by their peculiar odour of chlorine, and the copious disengagement of that gas on the addition of sulphuric acid.

The action of chloride of soda on the animal body has been examined by Segalas, who infers that it is an irritant poison, which, however, at times occasions symptoms of an affection of the nervous system. He remarked that three ounces of the solution, commonly sold in Paris under the name of Labarraque’s disinfecting liquid, caused immediate death by coagulating the blood in the heart, when injected into a vein in a dog. Two ounces introduced into the peritonæum excited palpitation, oppressed breathing, constant restlessness, and death in ten minutes; and three drachms did not prove fatal for some hours, tetanic spasms being produced in the first instance, and peritonæal inflammation being found after death. One ounce introduced into the stomach of a dog excited immediate vomiting, and no farther inconvenience; and two ounces retained by a ligature on the gullet brought on violent efforts to vomit, from which the animal was gradually recovering, when it was killed in twenty-four hours for the sake of observing the appearances. The stomach was found generally inflamed and interspersed with dark, gangrenous-like spots.[^[464]]

I am not acquainted with any case of poisoning with these substances in the human subject. But it is probable that symptoms of pure irritation and inflammation will occur, and that moderate doses may prove fatal.

CHAPTER X.
OF POISONING WITH LIME.

Lime, the last poison of the present group, is a substance of little interest to the toxicologist, as its activity is not great.

Its physical and chemical properties need not be minutely described. It is soluble, though sparingly, in water; and the solution turns the vegetable blues green, restores the purple of reddened litmus, gives a white precipitate with a stream of carbonic acid gas, and with oxalic acid a very insoluble precipitate, which is not redissolved by an excess of the test.

Its action is purely irritant. Orfila has found that a drachm and a half of unslaked lime, given to a little dog, caused vomiting and slight suffering for a day only, but that three drachms killed the same animal in five days, vomiting, languor, and whining being the only symptoms, and redness of the throat, gullet, and stomach, the only morbid appearances.[^[465]]

Though a feeble poison, it has nevertheless proved fatal in the human subject. Gmelin takes notice of the case of a boy who swallowed some lime in an apple-pie, and died in nine days, affected with thirst, burning in the mouth, burning pain in the belly, and obstinate constipation.[^[466]] A short account of a case of this kind of poisoning is also given by Balthazar Timæus. A young woman, afflicted with pica or depraved appetite, took to the eating of quicklime; and in consequence she was attacked with pain and gnawing in the belly, sore throat, dryness of the mouth, insatiable thirst, difficult breathing and cough; but she recovered.[^[467]] It is well known that quicklime also inflames the skin or even destroys its texture, apparently by withdrawing the water which forms a component part of all soft animal tissues. When thrown into the eyes it causes acute and obstinate ophthalmia, which may end in loss of sight. On this account it will belong, I presume, to the poisons included in the Scottish act against disfiguring or maiming with corrosives.

CHAPTER XI.
OF POISONING WITH AMMONIA AND ITS SALTS.

The second group of the order of alkaline poisons, including ammonia with its salts, and the sulphuret of potass, have a double action on the system, analogous to that possessed by many metallic poisons. They are powerful irritants; but they produce besides, through the medium of the blood, a disorder of some part of the nervous system; and their remote is sometimes more dangerous than their local action. The nervous affection produced by ammonia and the sulphuret of potass closely resembles tetanus, and therefore depends probably on irritation of the spinal column.

Of the Chemical tests for the Ammoniacal Salts.—Ammonia is when pure a gaseous body; but as commonly seen, it exists in solution in water, which dissolves it in large quantity. The solution has the usual effects of alkalis on vegetable colours, with the difference, however,—that the changes of colour are not permanent under the action of heat. It forms a yellow precipitate, as potass does, with chloride of platinum. It may at once be distinguished from other fluids by its peculiar pungent odour, which is possessed by no other substance except its carbonate.

Various carbonates are known in chemistry, but the only one known in commerce or met with in the shops is the sesqui-carbonate (subcarbonate—smelling salt—volatile salt—hartshorn). It is solid, white, fibrous, and has the same odour as pure ammonia. Its solution differs little in physical properties from the pure liquid ammonia; but, unlike it, is precipitated by the salts of lime.

The hydrochlorate (muriate of ammonia—sal-ammoniac)—is known by its solid, white, crystalline appearance; its ductility; its volatility; and by the effect of caustic potass and nitrate of silver, the former of which disengages an ammoniacal odour, while the latter causes in a solution of the salt a white precipitate, the chloride of silver.

Of the action of the Ammoniacal Salts, and their effects on man.—To determine the action of ammonia on the animal system, Professor Orfila injected sixty grains of the pure solution into the jugular vein of a dog. Immediately the whole legs were spasmodically extended; at times convulsions occurred; and in ten minutes it died. The chest being laid open instantly, coagulated florid blood was seen in the left ventricle, and black fluid blood in the right ventricle of the heart. No unusual appearance was discernible any where else except complete exhaustion of muscular irritability.[^[468]] The experiments of Mr. Blake also show that ammonia introduced in large doses into the veins acts by suddenly extinguishing the irritability of the heart. Small doses first lower arterial pressure from debility of the heart’s action, and then increase it by obstructing the systemic capillaries. When injected into the aorta from the axillary artery, it causes great increase of arterial pressure, owing to the latter cause; and then arrests the heart, while the respiration goes on. Four seconds are sufficient for the ammonia to pass from the jugular vein into the heart, so as to be discovered there by muriatic acid causing white fumes.[^[469]] Half a drachm of a strong solution, introduced by Orfila into the stomach of a dog and secured by a ligature on the gullet, caused at first much agitation. But in five minutes the animal became still and soporose; after five hours it continued able to walk; in twenty hours it was found quite comatose; and death ensued in four hours more. The only morbid appearance was slight mottled redness of the villous coat of the stomach. A third dog, to which two drachms and a half of the common carbonate were given in fine powder, died in twelve minutes. First it vomited; next it became slightly convulsed; and the convulsions gradually increased in strength and frequency till the whole body was agitated by dreadful spasms; then the limbs became rigid, the body and head were bent backwards, and in this state it expired, apparently suffocated in a fit of tetanus.[^[470]]

Several cases of poisoning with ammonia or its carbonate have occurred in the human subject. Plenck has noticed shortly a case which proved fatal in four minutes, and which was caused by a little bottleful of ammonia having been poured into the mouth of a man who had been bitten by a mad-dog.[^[471]] The symptoms are not mentioned, but it is probable, from the rapidity of the poisoning, that a nervous affection must have been induced. More generally, however, the effects are simply irritant; and the seat of the irritation will vary with the mode in which the poison is given. If it is swallowed, the stomach and intestines will suffer; if it is imprudently inhaled in too great quantity, inflammation of the lining membrane of the nostrils and air-passages will ensue. Huxham has related a very interesting example of the former affection, as it occurred in a young man, who had acquired a strange habit of chewing the solid carbonate of the shops. He was seized with great hemorrhage from the nose, gums, and intestines; his teeth dropt out; wasting and hectic fever ensued; and, although he was at length prevailed on to abandon his pernicious habit, he died of extreme exhaustion, after lingering several months.[^[472]] But the most frequent cases of poisoning with ammonia have arisen from its being inhaled, and thus exciting bronchial inflammation. An instructive instance of the kind has been related by M. Nysten. A medical man, liable to epilepsy, was found in a fit by his servant, who ignorantly tried to rouse him by holding assiduously to his nostrils a handkerchief dipped in ammonia. In this way about two drachms appear to have been consumed. On recovering his senses, the gentleman complained of burning pain from the mouth downwards to the stomach, great difficulty in swallowing, difficult breathing, hard cough, and copious expectoration, profuse mucous discharge from the nostrils, and excoriation of the tongue. The bronchitis increased steadily, and carried him off in the course of the third day, without convulsions or any mental disorder having supervened.[^[473]] A case precisely similar is related in the Edinburgh Medical and Surgical Journal. A lad, while convalescent from an attack of fever, was seized with epilepsy, for which his attendant applied ammonia under his nose “with such unwearied, but destructive benevolence, that suffocation had almost resulted. As it was, dyspnœa with severe pain of the throat and breast, immediately succeeded; and death took place forty-eight hours afterwards.”[^[474]] A third instance has been recorded of analogous effects produced by the incautious use of ammonia as an antidote for prussic acid. The patient had all the symptoms of a violent bronchitis, accompanied with redness and scattered ulceration of the mouth and throat; but he recovered in thirteen days.[^[475]] A fourth case, similar to the preceding, has been related by M. Souchard of Batignolles. A druggist, who inhaled while asleep the fumes of ammonia from a broken carboy, awoke in three-quarters of an hour, with the mucous membrane of the mouth and nostrils corroded, and a bloody discharge from the nose. A severe attack of bronchitis followed, during which he could not speak for six days; but being actively treated with antiphlogistic remedies, he recovered.[^[476]]—An extraordinary case has been published by Mr. Paget of death from injecting ammonia into the blood-vessels. A solution weak enough to allow of the nose being held over it was injected into a nævis in a child two years old. An attack of convulsions immediately followed, and in a minute the child expired.[^[477]]

Nysten’s case is the only one in the human subject in which the morbid appearances were ascertained. The nostrils were blocked up with an albuminous membrane. The whole mucous coat of the larynx, trachea, bronchi, and even of some of the bronchial ramifications, was mottled with patches of lymph. The gullet and stomach showed red streaks here and there; and there was a black eschar on the tongue, and another on the lower lip.

Of Poisoning with Hydrochlorate of Ammonia.—The effects of the hydrochlorate of ammonia on animals have been examined by Professor Orfila and Dr. Arnold; but I have not yet met with any instance of its operation as a poison on man. When given to dogs it irritates and inflames the parts it touches, and causes the ordinary symptoms of local irritation. But it also acts remotely. For, first, like arsenic, and other poisons of the third order of irritants, it produces inflammation of the stomach, in whatever way it is applied to the body,—Orfila having found that organ affected when the salt was applied to the subcutaneous cellular tissue;[^[478]] and, secondly, according to the experiments of Arnold, it causes, when swallowed, excessive muscular weakness, slow breathing, violent action of the heart, and tetanic spasms,—effects which cannot arise from mere injury of the stomach. Half a drachm will thus kill a rabbit in eight or ten minutes;[^[479]] and two drachms a small dog in an hour.[^[480]]

CHAPTER XII.
OF POISONING WITH THE ALKALINE SULPHURETS.

The liver of sulphur, or sulphuret of potass of the pharmacopœias, the last poison of this order to be mentioned, is allied to the ammoniacal salts in action. It is of no great consequence in a toxicological point of view in this country, being put to little use; but several accidents have been caused by it in France, where it is employed for manufacturing artificial sulphureous waters; and farther, its properties should be accurately ascertained, because till lately it was erroneously resorted to as an antidote for some metallic poisons.

Chemical Tests.—It has a grayish, greenish, or yellowish colour when solid; its dust smells of sulphuretted hydrogen, which is also copiously disengaged from it by the mineral acids: and it forms with water a yellow solution of the same odour.—In composite fluids it may be detected by heating it with acetic acid, and passing the disengaged gases through solution of acetate of lead, in which a black precipitate of sulphuret of lead is produced, from the action of sulphuretted-hydrogen.[^[481]]

Action and Symptoms.—Orfila found that a solution of six drachms and a half, secured in the stomach of a dog by a ligature on the gullet, caused death by tetanus in seven minutes, without leaving any morbid appearance in the body; that inferior doses caused death in the same manner, but at a later period, and with symptoms of irritation in the alimentary canal, which also was seen red, black, or even ulcerated after death; that a solution of twenty-two grains injected into the jugular vein killed a dog in two minutes, convulsions having preceded death, and the heart being found paralysed immediately after it; and that a drachm and a half thrust in small fragments under the skin occasioned death in thirteen hours with coma and extensive inflammation of the cellular tissue.[^[482]] There can be no doubt, therefore, that liver of sulphur is a true narcotic acrid poison.—It is absorbed, and may be detected in the blood, liver, kidneys, and urine by Orfila’s process.[^[483]]

Orfila has collected three cases of poisoning in the human subject with this substance;[^[484]] and a fourth has been related by M. Cayol.[^[485]] Of these cases two proved fatal in less than fifteen minutes; and the symptoms were acrid taste, slight vomiting, mortal faintness, and convulsions, with an important chemical sign, the tainting of the air with the odour of sulphuretted-hydrogen. The dose in one case was about three drachms. The two other patients, who recovered, were for some days dangerously ill. The symptoms were burning pain and constriction in the throat, gullet, and stomach; frequent vomiting, at first sulphureous, afterwards sanguinolent; purging, at first sulphureous; sulphureous exhalations from the mouth; pulse at first quick and strong, afterwards feeble, fluttering, and almost imperceptible; in one case sopor; finally severe inflammation of the gullet, stomach and intestines, which abated in three days. One of these patients took four drachms of sulphuret of soda, the other two ounces of sulphuret of potass; but it is probable, that the latter dose was partly decomposed by long keeping.

Morbid Appearances.—The morbid appearances in the two fatal cases were great lividity of the face and extremities, and exhaustion of muscular contractility immediately after death; the stomach was red internally, and lined with sulphur; the duodenum also red; the lungs soft, gorged with black fluid blood, and not crepitant.

Treatment.—The most appropriate treatment consists in the instant administration of any diluent, then of frequent doses of the chloride of soda, and lastly the antiphlogistic mode of subduing inflammation. The chloride of soda or lime decomposes sulphuretted hydrogen, the disengagement of which is the probable cause of death in the quickly fatal cases.[^[486]]

CHAPTER XIII.
OF POISONING WITH ARSENIC.

The third order of the irritant class of poisons includes the compounds of the metals. These are of great importance to the medical jurist. They are frequently used for criminal purposes; they give rise to the greatest variety of symptoms; and the medical evidence on trials respecting them, while much skill is required on the part of the witness to collect it, is also the most conclusive.

It must not be inferred from their being arranged in the class of irritants that their action is merely local. In fact this is the case with a very few of them only, which produce chemical corrosion. The greater number likewise act indirectly on organs at a distance from the part to which they are applied. Nevertheless the most prominent symptoms generally produced by them are those of violent local irritation; so that they may be justly considered in the place which has been assigned them.

The poisons included in this order are the oxides and salts of arsenic, mercury, copper, antimony, tin, silver, gold, bismuth, iron, chrome, zinc, barium, lead. Many other metals also form poisonous compounds with various acids and other bodies; but these are so rare as to be merely objects of physiological curiosity.

Of all the varieties of death by poison, none is so important to the medical jurist as poisoning with arsenic. On account of the shameful facility with which it may be procured in this country, even by the lowest of the vulgar, and the ease with which it may be secretly administered, it is the poison most frequently chosen for the purpose of committing both suicide and murder. In 1837 and 1838 no fewer than 186 cases of fatal poisoning with arsenic were known to have occurred in England alone (see p. [90]). Of 221 cases of murder by poison in France during ten years subsequent to 1829, in which the poison given was ascertained, there were 149 where the substance administered was arsenic.[^[487]] It is fortunate, therefore, that there are few substances in nature, and perhaps hardly any other poison, whose presence can be detected in such minute quantities and with so great certainty.

Section I.—Of the Chemical Tests for the Compounds of Arsenic.

Metallic arsenic has an iron-gray colour, a specific gravity of 8·308, and a crystalline fracture. It is very brittle. It has a strong tendency to oxidate, so that it undergoes this change in air, in water, and even in alcohol. In air, particularly when moist, it becomes rapidly tarnished, a black powder being formed, which some have regarded as a regular protoxide.[^[488]]—When exposed to heat, metallic arsenic is usually said to sublime at the temperature of 356° F.; but according to some late experiments by Dr. Mitchell of Philadelphia this does not happen under a low red heat, luminous in the dark.[^[489]] In close vessels it condenses unchanged; but when heated in the open air, it passes to the state of white oxide, and rises in white fumes. This substance is a sesquioxide, consisting of two equivalents of metal and three of oxygen. Another oxide likewise exists, which contains two equivalents of metal and five of oxygen, and, possessing strong acid properties, is denominated arsenic acid. The sesquioxide and arsenic acid unite with bases, and produce compounds which, with the exception of those they form with the alkalis, are mostly insoluble. Metallic arsenic unites with sulphur in two proportions, forming an orange-red and a sulphur-yellow compound. The compounds of arsenic have very little chemical action with vegetable and animal principles.

Of the compounds which arsenic thus forms, those which it will be necessary to particularize are the following:—1. The protoxide of Berzelius, or fly-powder. 2. The arsenious acid, or white arsenic. 3. The arsenite of copper, or mineral green. 4. The arsenite of potass as contained in Fowler’s solution. 5. The arsenite of potass; 6. The various sulphurets, pure and impure, namely, realgar, orpiment, and king’s yellow; and 7. Arseniuretted-hydrogen gas.

Of the Tests for Fly-powder.

This substance is rarely known as a poison in Britain, but is a familiar poison in France and Germany, under the names of Poudre à mouches, and Fliegenstein. Of late it has been occasionally used in Scotland for poisoning rats.

It is a fine grayish-black powder, formed by exposing powdered arsenic for a long time to the air; but it also frequently contains fragments of the metal. It is usually considered by chemists to be a mixture of metallic arsenic and its white oxide.

It is acted on by water, the white oxide being found ere long in solution by its proper tests. Oxidation and solution, however, are also effected upon pure metallic arsenic in the same manner. A thousand grains of water take up a grain in the course of half an hour when boiled on the metal.[^[490]]

A very simple and decisive test for fly-powder is derived from the effect of heat. If it is heated in a tube two substances are sublimed, first a white crystalline powder, and then a bright metallic crust, the former being the white oxide, the latter the metal. The metallic crust thus formed possesses physical properties, which distinguish arsenic from all other substances, capable of being sublimed by a low heat: The surface next the tube is very like polished steel, being a little darker in colour, but equal in brilliancy and polish; and the inner surface is either brilliantly crystalline to the naked eye, like the fracture of cast-iron, or has a dull grayish-white colour, but appears crystalline before a common magnifying lens of four or five powers. If these characters be attended to, particularly the appearance of the inner surface, it appears to me scarcely possible to mistake for an arsenical crust any other substance which can be sublimed by any of the methods for subliming arsenic.

If a farther test should be desired, it is only necessary, as was first proposed by Dr. Turner of London,[^[491]] to chase the crust up and down the tube with the spirit-lamp flame till it is all oxidated, when little octaedral crystals of adamantine lustre are formed, on which, either with the naked eye or with the aid of a common lens, triangular facettes may be distinguished.

The niceties to be attended to in applying the preceding tests will be considered presently under the head of the next compound, the sesquioxide.

2. Of the Tests for Arsenious Acid.

Arsenious acid, the sesquioxide, or white oxide of arsenic, usually called white arsenic, or simply arsenic, is the most common and important of all the arsenical preparations.

It is met with in the shops in two forms,—as a snow-white gritty powder, and in solid masses generally opaque, but sometimes translucent. When newly sublimed it is in translucent or even almost transparent masses of a vitreous lustre, conchoidal fracture and sharp-edged. By keeping it becomes opaque and white. The nature of the change has not been determined; but some alteration is certainly effected, for Guibourt, who has examined both varieties with care, found that the opaque variety is more soluble in water than the other. He adds that the former is alkaline, the latter acid, in its action on litmus paper; but I have always found the opaque variety acid.[^[492]] The powder soon becomes analogous to the opaque variety of the oxide in mass.

The oxide of arsenic has a specific gravity of 3·729, according to the experiments of Dr. Ure,—of 3·529 when opaque, according to Mr. Alfred Taylor, and 3·798, when translucent. Very incorrect notions prevail as to its taste. It was long universally believed to be acrid,[^[493]] and is described to be so in many systematic works and express treatises; but in reality it has little or no taste at all. The reader will find some details on this point in a paper I published in the Edinburgh Medical and Surgical Journal.[^[494]] In the present work it is sufficient to observe, that I have repeatedly made the trial, and seen it made at my request by several scientific friends, and that, after continuing the experiment as long, and extending the poison along the tongue as far back, as we thought safe, all agreed that it had scarcely any taste at all,—perhaps towards the close a very faint sweetish taste. It appears to me that the experiments made on that occasion might have set at rest the question as to the taste of arsenic, and corrected an important error long committed by systematic authors in chemistry as well as medical jurisprudence. And accordingly in this country the truth is generally known.[^[495]] Professor Orfila, however, continues to repeat the error; for even in the last edition of his Toxicologie he says it has “a rough, not corrosive, slightly styptic taste, perceptible not for a few seconds, but persistent, and attended with salivation.”[^[496]] These sensations must be either imaginary or the indications of an organ peculiarly constituted. It is impossible to make satisfactory experiments with safety on its impressions on the back of the palate. But we may rest assured that in general it makes no impression there at all; for it has been often swallowed unknowingly with articles of food. Not a few have in such circumstances noticed merely its grittiness, and thought there was sand in their food. Two instances only am I hitherto acquainted with, where an acrid sensation would seem really to have been experienced in the act of eating or swallowing. In one of these, noticed in Rust’s Journal, the individual who was poisoned, could not finish the poisoned dish on account of its unpleasant, very peppery taste.[^[497]] In the other case, which was lately communicated to me by Mr. Hewson of Lincoln, the individual, who was poisoned by arsenic dissolved in his tea-kettle,—happening in the first instance to wash his mouth with the water,—observed at the time to his daughter, that it had a very odd taste; which subsequently was called a burning taste. These facts, however, are evidently not altogether satisfactory. It is not improbable that, in an ex post facto description, the reporters, as others in the same circumstances have clearly done[^[498]], confounded the subsequent inflammation with mere taste in the act of chewing or swallowing. At all events it is absolutely certain that the great majority of people who have been poisoned with arsenic remarked in taking it either no taste at all, or merely a roughness owing to the gritty condition of its powder.

The oxide of arsenic when subjected to heat is sublimed at 380°, or, according to Dr. Mitchell, 425° F.[^[499]] and condenses in the form of a crystalline powder, which, if the operation is performed slowly and on a small quantity proportioned to the size of the tube, evidently consists of little, adamantine octaedres.—When it is mixed with carbonaceous matter and heated, it is reduced, and the metal is sublimed. This constitutes the test of reduction, which, when conducted with due care, may be rendered singly a certain proof of the presence of arsenic.

Water dissolves it. Its solubility is a point of some medico-legal importance; for a doubt may arise whether the quantity of a solution that has been swallowed contained a sufficient dose to cause severe symptoms or death. Different statements have gone forth on this head. Klaproth found, that a thousand parts of temperate water take up only two parts and a half,—and that a thousand parts of boiling water take up 77·75 parts or a thirteenth, and retain on cooling 30 parts or a thirty-third of their weight.[^[500]] Guibourt found a difference between the transparent and opaque varieties; for a thousand parts of temperate water dissolved in thirty-six hours 9·6 of the transparent, 12·5 of the opaque variety; and the same quantity of boiling water dissolved of the transparent variety 97 parts, retaining 18 when cooled, but of the opaque variety took up 115 and retained on cooling 29.[^[501]] More lately Mr. Alfred Taylor observed that temperate water, simply poured on the opaque oxide and left for seventy-two hours, contained one grain in a thousand, but if often agitated, 8·5 grains; that boiling water, occasionally agitated for the same period, contained 9·27 or 9·54 grains; that water, boiling gently for an hour dissolved 31·5, and on cooling and resting for three days retained 17; that with violent ebullition for an hour, it took up 46·3, and retained 24·7 grains on cooling and resting for three days; that a saturated boiling solution after six months contained 24 or 26 grains; and that a saturated boiling solution of the transparent oxide contained 46 or 47·5 grains, and on cooling and resting for two days retained 18·7 or 13·4 grains.[^[502]] It is impossible to account for these discrepancies; for all the experimentalists conducted their investigations with care, and with a view to the medico-legal question stated above. Hahnemann farther remarked, that at the temperature of the blood a thousand parts of water dissolve ten parts with the aid of ten minutes’ agitation;[^[503]] and Navier, that boiling water kept for an hour on it, and decanted off in the way an infusion is usually made, dissolves 12·5 grains in every thousand.[^[504]]

Its solubility is impaired by the presence of organic principles. When mixed with mucus or milk it dissolves, according to Hahnemann, with great difficulty; and I have found that a cup of tea, left beside the fire at a temperature of 200° for half an hour upon two grains of the oxide, does not take up entirely even that small quantity. An important consequence of the fact now mentioned is, that when swallowed in the solid state, little or no arsenic may be found in the fluid contents of the stomach. In a case which occurred to Scheele three grains of solid arsenic were found in the contents, but hardly a trace in solution.[^[505]] It would be wrong, however, to suppose that it is never found in the fluid contents. For, not to mention the observations of others, I have myself often detected it in the fluid part of the stomach in persons poisoned by arsenic.

The solution of oxide of arsenic in boiling water yields minute crystals on cooling, which, when their form is defined, are octaedres. In this state, on account of its whiteness and brilliancy, it exceedingly resembles pounded sugar. By spontaneous evaporation I have procured in twelve months fine octaedres nearly as large as peas. These do not become opaque by keeping, like the sublimed masses.

A difference of opinion prevails as to the action of the oxide on vegetable colours. This is a matter of no great consequence to the medical jurist; but it is right not to leave a disputed point without some notice. Guibourt says the transparent variety faintly reddens litmus, while the opaque variety faintly restores to blue litmus previously reddened.[^[506]] My own experiments are at variance with these statements: I have always found that the solution of the powder, which is of the opaque variety, faintly reddens litmus, and does not alter reddened litmus.

The remaining chemical properties of the oxide, which it is necessary for the medical jurist to know, will be mentioned under what is now to be said of the principal test by which its presence may be ascertained. Under this head will be noticed, first the tests for the solid oxide, secondly, those for its solution, and lastly, the method of detecting it when mingled with vegetable or animal solids and fluids, such as the contents and tissues of the stomach.

Of the Tests for Arsenic in the solid state.

The most characteristic and simple test for oxide of arsenic in its solid state, either pure or mixed or combined with inorganic substances, is its reduction to the metallic state.

Various methods have been at different times proposed for employing the test of reduction. In the ruder periods of analytic chemistry we find Hahnemann recommending a retort as the fittest instrument, and stating ten grains as the least quantity he could detect.[^[507]] Afterwards Dr. Black substituted a small glass tube, coated with clay and heated in a choffer; and in this way he could discover a single grain.[^[508]] In a paper published in the Edinburgh Medical and Surgical Journal, I showed how to detect a sixteenth of a grain; and afterwards even so minute a quantity as a hundreth part of a grain.[^[509]]

The process is performed in a glass tube; which, when the quantity of the oxide is very small, should not exceed an eighth of an inch in diameter, and may be conveniently used of the form first recommended by Berzelius, and represented in Fig. 3.—The best material for reducing the oxide is recently ignited charcoal, if the quantity of suspected substance be very small. For when any of the ordinary alkaline fluxes is used, more than half of the arsenic is retained, probably in the form of an arseniuret of the alkaline metalloid. But when the quantity of matter for analysis is considerable, charcoal is inconvenient, as it is apt to be projected up the tube on the application of heat; and an alkaline flux is on that account preferable. For this purpose soda-flux,—made by grinding crystals of carbonate of soda with an eighth of their weight of charcoal, and then heating the mixture gradually to redness, so as to drive off all water,—is better than the more familiar black flux, which contains carbonate of potash; because the latter attracts much moisture when kept for some time.—If the quantity operated on is large it should be mixed with the flux before being introduced into the tube; if it is small, it may be dropped into the tube and covered with charcoal. The materials are to be introduced along a little triangular gutter of stiff paper, if the tube is large; but with a small tube it is preferable to use the little glass funnel represented in Fig. 2, to which a wire is previously fitted, for pushing the matter down when it adheres. The material should not be closely impacted. Heat is best applied with the spirit-lamp, first to the upper part of the material, with a small flame, and then to the bottom of the tube, the flame being previously enlarged. A little water, disengaged in the first instance, should be removed with a roll of filtering paper, before a sufficient heat is applied to sublime the metal. As soon as the dark crust begins to form, the tube should be held steady in the same part of the flame. With these precautions a well defined crust will be procured with facility.

The characters of the crust have been mentioned already under the head of fly-powder (p. [199]). They are distinct even in crusts weighing only a 300th of a grain. A crust of this weight, a tenth of an inch broad and four times as long, may show characteristically all the physical characters of an arsenical sublimate a hundred times larger.

The fallacies to which the test has been supposed to be liable (excluding at present that part of it which consists in the oxidation of the metal, and which renders it quite unimpeachable), are the following.— Dr. Paris says he has known an instance where a person, “by no means deficient in chemical address, mistook for it a deposit of charcoal,”[^[510]] and I have known the same mistake happen in the hands of one of my pupils, a beginner in the study of medico-legal chemistry. The outer surface of a charcoal crust may be mistaken for arsenic by a careless person; but with ordinary care it is quite impossible to err if the inner surface be examined, for that of charcoal is brown, powdery, and perfectly dull.—It has been suggested to me and has been stated in print,[^[511]] that the preparations of antimony yield by reduction a sublimate resembling closely an arsenical crust. But in consequence of repeated trials I am certain that no preparation of antimony, reduced either by charcoal or the black flux with the fullest red heat of the blowpipe will yield any metallic sublimate; and the same facts were observed by the late Dr. Turner.—It has even been said by Mr. Donovan that the action of the flux on glass which contains lead causes a stain similar to an arsenical crust.[^[512]] If it be meant by this observation, that the lead contained in the glass usually gives that part of the tube which contains the flux a glimmering appearance and impairs its transparency, the author is correct: but it is impossible that a sublimate can be so formed.—Dr. Mitchell of Philadelphia in an elaborate paper on the process of reduction seems to consider the crust undistinguishable from that formed in similar circumstances by cinnabar.[^[513]] Crusts of cinnabar, however, do not present the peculiar character possessed by the internal surface of arsenic.—Zinc, it is said, may be sublimed in its metallic state; but the sublimation of zinc requires a full white heat; which in the process for arsenic cannot be generated.—Tellurium, cadmium, and potassium sublime at a lower heat; but these metals are so exceedingly rare, that it is quite unnecessary to particularize the characters of their sublimates.—Lastly, it is said that a crust may be produced from arsenic contained in the glass of the tube. A few years ago MM. Ozanam and Idt of Lyons detected arsenic in the remains of a body which had been seven years interred; but subsequently M. Idt imagined he had discovered that the glass used in the analysis contained arsenic, and yielded it by the process of reduction. He accordingly retracted his original opinion; and the person accused of administering the poison was acquitted. An extended inquiry, however, was in consequence undertaken by the Parisian Academy of Medicine at the request of the French government. And the result was that no arsenic could be detected in the glass tubes used by MM. Ozanam and Idt; and that although arsenic is sometimes used in glass-making, and a trace of it may be retained in some opaque glasses or enamels, it cannot be detected by any process of analysis in any of the clear glass met with in commerce,[^[514]] the whole arsenic being volatilized during the manufacture of the glass.

It may therefore be safely laid down that the appearances exhibited by a well-formed arsenical crust, even in the minute quantity of a 300th part of a grain, are imitated by no substance in nature which can be sublimed by the process for the reduction of arsenic.

But should farther evidence be required as to the nature of the crust, this may be obtained by subjecting it to oxidation by heat.

The best method of doing so is to heat the ball containing the flux deprived of arsenic, to attach a bit of glass tube to its end, and to draw this gently off in the spirit-flame, taking care to prevent the flux being driven forward on the crust. This being done, the whole crust, or, if it is large, a portion of it, is to be chased up and down the tube with a small spirit-lamp flame till it is all converted into a white powder. In order to show the crystalline form of the powder distinctly, let the flame be reduced to the volume of a pea by drawing in the wick, and let the part of the tube containing the oxide be held half an inch or an inch above it. By repeated trials sparkling crystals will at length be formed, which are octaedres,—the crystalline form of arsenious acid. The triangular facettes of the octaedres may be sometimes seen with the naked eye, though the original crust was only a fiftieth of a grain or even less; and they may be always seen with a lens of four powers, the tube being held between the eye and a lighted candle or a ray of sunshine, either of which is preferable to diffuse daylight for making this observation.—For the success of the oxidation test it is indispensable that the inside of the tube be not soiled with an alkaline flux: because the alkali would unite with the oxide. It is also requisite not to heat the tube suddenly to redness before the oxide is sublimed; because then the oxide is apt to unite with the glass, forming a white, opaque enamel. The physical characters of the sublimed oxide are so delicate and precise, that they may be accurately distinguished, even when those of the metallic crust are obscure, owing to its minuteness. Sometimes too, the metal may be so scanty that it is oxidated at once in the act of subliming, and never presents the appearance of a metallic crust. Although the characters of the crystalline oxide in either of these cases are very precise and distinctive, it may be right to subject it to a farther test when the metal is not previously exhibited with its characteristic properties. For this purpose it is sufficient to cut away with a file the portion of the tube which contains the sublimate, to boil it in another tube with a few drops of distilled water till the sublimate disappear, and then to test the solution with one of the fluid tests to be presently described, the ammoniacal nitrate of silver.

After all that has been recently written as to the old and newer processes for detecting arsenic, I must nevertheless avow my conviction, that for solid arsenic no test is, for medico-legal purposes, at once so satisfactory, convenient, and delicate as the test of reduction, especially with the addition of the supplementary test of oxidation. That other methods are still more delicate may be readily granted. But where the suspected substance is in the solid form, what possible occasion can there be for a method more delicate than one which will detect a 300th part of a grain? A method ten times less so would meet every case in actual practice.—A variety of supplementary tests have been proposed. But they are all greatly inferior in facility, or conclusiveness, or both, to the process of oxidation, and ought therefore to be expelled from medico-legal practice,—not even excepting the alliaceous odour of metallic arsenic in the act of subliming, a character, the fallaciousness of which was long ago pointed out by myself as well as others, and to which a preposterous importance has been attached in some late inquiries. The reader will find in the last edition of this work an attempt to estimate the value of various tests supplementary to that of reduction. This disquisition is now omitted, as it seems no longer necessary.

Of the Tests for Oxide of Arsenic in Solution.

Oxide of arsenic in a state of solution may be detected in one of four ways; by what are called the liquid tests; by precipitating it with one of these, and subliming metallic arsenic from the precipitate, which method is usually termed the reduction process; by Marsh’s method, which consists in disengaging it in the form of arseniuretted-hydrogen gas, and decomposing the gas by combustion; or by the method of Reinsch, in which metallic arsenic is deposited on the surface of copper, and then separated by heat for farther examination.

Process by Liquid Reagents.—The first method is by the employment of several liquid tests, which cause in the solution peculiar precipitates. Many such tests have been proposed; but the most characteristic and precise are hydrosulphuric acid, ammoniacal nitrate of silver, and ammoniacal sulphate of copper. The indications of each of the three tests must concur, otherwise, in a medico-legal case, no one can be entitled to speak with certainty to the existence of arsenic. But when they do concur, the evidence is unimpeachable. When this method of analysis is followed, corresponding experiments ought always to be made with the water that is used for diluting or otherwise preparing the subject of examination, or with distilled water, if the article be already sufficiently aqueous. This precaution is necessary on account of the risk of accidental impregnation of the water or other reagents with arsenic.[^[515]]

Hydrosulphuric acid [sulphuretted-hydrogen] is obtained by decomposing proto-sulphuret of iron with diluted sulphuric acid in such an apparatus as is represented at Fig. 5. And the gas may be either applied directly to the suspected fluid, or condensed in distilled water, and thus kept in store for occasional use in the liquid shape. Before applying this test, the suspected fluid must be acidulated with acetic or hydrochloric acid; because an excess of alkali prevents the action. And if an acid be indicated by litmus in the fluid, neutralization, or slight supersaturation, with potash must be effected, before adding acetic or hydrochloric acid; for if the acidity should happen to be owing to an excess of sulphuric or nitric acid, the test is decomposed, and yellowish-white sulphur deposited.—These precautions being taken, hydrosulphuric acid occasions a sulphur-yellow or lemon-yellow precipitate. If the arsenical solution, however, be very weak, a yellow colour merely is struck, because the precipitate, which is sesqui-sulphuret of arsenic, is dissolved by the excess of the test; but it separates after ebullition, or a few hours’ exposure to the air. Co-existing animal and vegetable principles sometimes enable the fluid to retain a minute portion even after ebullition, so as to acquire a yellow milkiness; but they do not in any case prevent the test from producing the yellow colour. Acidulation with acetic or hydrochloric acid favours its subsidence in all cases; and according to Mr. Boutigny, alkaline sulphates, muriates and nitrates have the same effect.[^[516]] Hydrosulphuric acid is so delicate as to act on the oxide in a hundred thousand parts of water. The proper colour of the precipitate is lemon or sulphur-yellow; which, when vegetable or animal matter is present, acquires a shade of white or brown.

It is not liable to any material fallacy. The salts of cadmium yield with it precipitates nearly of the same colour: but they are exceedingly rare; and the precipitate, unlike sulphuret of arsenic, is insoluble in ammonia.—The salts formed by selenic acid, if decomposed by another acid, also yield yellow precipitates; but these salts are extremely rare.—The salts of peroxide of tin give a dirty grayish-yellow precipitate; which however ammonia turns brown.—A lead solution acidulated with hydrochloric acid gives at first a yellow precipitate; but this becomes brownish-black when more gas is transmitted.[^[517]] The contents of the human intestines sometimes yield a yellowish precipitate though no arsenic be present; and it is dissolved, like sulphuret of arsenic, by ammonia.[^[518]] The tartrate of antimony and potash (tartar-emetic) does not form, as was once thought, any source of fallacy, the antimonial precipitate having always a tint of orange-red; besides it is not, like sulphuret of arsenic, soluble in carbonate of ammonia.—Other fallacies exist, unless the test be used with the precautions mentioned above. But these need not enumeration here.

Ammoniacal nitrate of silver is prepared by precipitating the oxide of silver by means of ammonia, from a solution of nitrate of silver or lunar caustic in ten parts of water, and then redissolving the precipitate nearly, but not entirely, by adding gradually an excess of ammonia. When thus prepared, it causes, even in a very diluted solution of the oxide of arsenic, a lively lemon-yellow precipitate of arsenite of silver; which passes to dark brown under exposure to the light.—The action of this test is prevented by nitric, acetic, citric, or tartaric acid in excess, particularly by the first and last. It is also prevented by an excess of ammonia; and in very diluted solutions by the nitrate of ammonia. These facts will suggest the necessity of certain obvious precautions. Its action is obscured by the co-existence of various salts, which singly cause a white precipitate with nitrate of silver; for the yellow colour is then much lessened in intensity. The only one of these requiring special notice, because it occurs in very many of the fluids which are likely to be subjected to the researches of the medical jurist, is common sea-salt, the chloride of sodium. The best way of getting rid of the difficulty is to use in the first instance, not the ammoniacal nitrate, but the simple nitrate of silver, as long as any white precipitate falls down, to add a slight excess of that test, and then, after subsidence, to drop in ammonia. No arsenic is thrown down by the first steps of this process; but if any be present, it is subsequently thrown down in the form of the yellow arsenite of silver, on the addition of ammonia. This simple mode of getting rid of chloride of sodium was first proposed by Dr. Marcet.[^[519]]—Ammoniacal nitrate of silver is of no use as a test for a moderately diluted solution of the oxide of arsenic, if vegetable or animal matter be present; either the colour of the precipitate is essentially altered, or no precipitate is formed at all.[^[520]]

If the presence of arsenic is to be inferred only when the full lemon-yellow colour of the precipitate is developed, this test is not liable to any material fallacy. The presence of a phosphate, a serious obstacle according to an old way of using the silver test, is not a source of fallacy in the instance of the ammoniacal nitrate; for the yellow phosphate of silver is so soluble in the ammonia of the test, that it is not thrown down unless the phosphatic solution is very strong.—The silver test, which is extremely delicate, was proposed by Mr. Hume, a chemist of London; and in its improved state was suggested by the late Dr. Marcet. Various foreign authors have fallen into the error of supposing that nitrate of silver without an alkali precipitates oxide of arsenic: without an alkali, pure nitrate of silver gives no precipitate, or at most a bluish-white or yellowish-white haze when both solutions are strong.

Ammoniacal sulphate of copper is prepared by the same process with the last test, sulphate of copper being substituted for nitrate of silver. It is a test of very great delicacy. It causes in solutions of the oxide of arsenic an apple-green or grass-green precipitate of the arsenite of copper. The particular tint is altered apparently by trifling circumstances; but after the precipitate has stood some hours it always assumes a tint intermediate between apple-green and grass-green. The operation of this test is prevented by hydrochloric, nitric, sulphuric, acetic, citric, and tartaric acids in excess; and also by an excess of ammonia. These difficulties are obviated by manifest precautions. It is also prevented, according to Hünefeld, by muriate, nitrate, and sulphate of ammonia;[^[521]] and by almost all vegetable infusions and animal fluids, when the oxide of arsenic is not abundant: these difficulties cannot be obviated. Even when not prevented by such fluids, its operation is often obscured, the precipitate not possessing its characteristic colour.

Ammoniacal sulphate of copper is more open to fallacies than the silver test. Of these the most important is that in some organic fluids it strikes a green precipitate, like the arsenite of copper, though arsenic be not present.[^[522]] The solution of bichromate of potass is turned green but not precipitated by it.

On reviewing all that has now been stated regarding the liquid tests for arsenic, it will appear that there is no single test on which absolute reliance can be placed; but that the fallacies to which they are liable are generally remote, and each of them applicable to one test only. Hence if each of the three reagents, applied with due care, gives a precipitate of the characteristic tint, the proof of the presence of arsenic is decisive.

This particular view of the indications of the liquid tests, however obvious it may seem, has been often overlooked by the numerous chemists and medical jurists who have written for and against them. The antagonists of the tests have been content with proving how so many fallacies lie in the way of each, that no dependence can be put in any one of them: They have not considered that the fallacies attached to one are obviated by the conjunct indications of the others.

I am of opinion therefore that the analysis for arsenic by liquid reagents has been unjustly neglected in the present day. It is an exceedingly convenient method, and one of extreme delicacy, because by using small tubes it is easy to operate with precision on very minute portions of a suspected fluid. It is also perfectly conclusive, so far as chemical knowledge now goes. On a remarkable trial a few years ago in this country, a distinguished chemist, who, as witness for the prisoner, was made by counsel to throw discredit on the liquid tests individually, nevertheless admitted to the counsel for the prosecution, that no other substance in nature but arsenic could produce the same effects as it with the whole three tests in succession.

Reduction process.—The process by reduction of arsenic to the metallic state, as applied to the poison in a state of solution, consists in separating the whole arsenic by a liquid test in such a state as to admit of the precipitated compound being subjected to the process of reduction and sublimation. The best method of the kind is a modification of one described by me in 1824.[^[523]] This consists in throwing down the whole arsenic in the form of sulphuret by means of hydrosulphuric acid, converting the sulphuret by the process of reduction to the metallic state, and oxidating the metal thus procured. The hydrosulphuric acid is preferred to other liquid reagents, because the precipitate it forms, while possessing a very characteristic colour, is also more bulky than those caused by the other tests, and is therefore more easily collected,—and because its action is not liable to be prevented or obscured by so many disturbing causes. The steps of the process are the following:—

The fluid to be examined must be acidulated with acetic or hydrochloric acid. If the fluid be neutral or alkaline, the acid may be added at once. If on the other hand the fluid redden litmus, and the acid be either unknown or a mineral acid, potash must first be added in a slight excess, and then the alkali must be supersaturated with acetic or hydrochloric acid. The reasons for these precautions are stated under hydrosulphuric acid as a liquid reagent. The fluid being thus prepared, it is subjected to a stream of hydrosulphuric acid gas for ten or fifteen minutes. The first portions of the gas turn the arsenical solution to a bright lemon-yellow colour, and the subsequent portions throw down a yellow flocculent sulphuret of arsenic. If the proportion of oxide in solution is small, a yellowness or yellow milkiness only is caused, owing to the sulphuret being soluble in an excess of hydrosulphuric acid. But on expelling that excess by boiling, a distinct precipitate and colourless fluid are produced. The precipitate is then to be collected thus. The precipitate is allowed to subside, and the supernatant fluid being withdrawn, the remainder is poured into a filter. When all the fluid has passed through, the portions of precipitate on the upper part of the filter are washed down to the bottom. The filter is then gently compressed between folds of bibulous paper, and the sulphuret removed with the point of a knife before it dries, and dried in little masses on a watch-glass by the side of a chamber-fire, or still better in a vapour-bath. In this way it is very easy to collect a twenty-fifth part of a grain of the sulphuret. Another method which takes more time, but will enable the least skilful person to collect extremely small quantities, is to allow the sulphuret to subside in the original fluid in which it is formed, to pour off the supernatant liquid, and pour the remainder into a small glass tube, Fig. 7. After the precipitate has thoroughly subsided, the supernatant liquid is to be withdrawn, and its place filled up with boiling water. The operation of alternate subsidence and affusion being repeated a sufficient number of times, the last portions of water should be gently driven off by heat, and wiped off the inside of the tube as the drops condense on it. Finally, the bottom of the tube, with the precipitate attached, is to be cut away with the file, and broken into small fragments with the view of preserving the whole sulphuret for the process of reduction. The sulphuret having been collected in either of these ways, it is now to be dropt into the tube, Fig. 3, and covered by means of the funnel, Fig. 4, with soda-flux. The process in other particulars is the same with that for reducing solid oxide of arsenic.

This method of investigation gives extremely precise results, because it presents the poison successively in three distinct forms, as sulphuret, metal, and crystallized oxide, all of which possess very prominent and characteristic external properties. It is also a method which is capable of detecting very minute quantities of oxide of arsenic. And it has the advantage over the process by liquid reagents of being applicable to organic fluids. It was accordingly followed in most medico-legal researches until the recent discovery of the methods of Marsh and Reinsch.

In order to render it quite satisfactory, it is necessary to go through the steps of the analysis at the same time with distilled water, lest any of the reagents used should accidentally contain arsenic.

Process of Marsh.—This method consists in disengaging arsenic from the solution in the form of arseniuretted-hydrogen gas, burning the gas in such way as to obtain either metallic arsenic or oxide of arsenic, and subjecting the product to various tests.

I have called this beautiful method of analysis Marsh’s process, because it appears to me that injustice has been done its discoverer both by himself and those who have since investigated the subject, when they denominated it merely a test. Medico-legal analysis stood in no need of a new test for arsenic, but very much of an easy and infallible method of detaching minute quantities of it in a state of purity from simple and compound fluids, so as to admit of its being accurately examined. It is this important object, and not strictly speaking a new test, that has been attained through means of the discovery of Mr. Marsh.

His discovery consists in the observation, that, if hydrogen gas be disengaged by the action of sulphuric acid or zinc in a fluid containing arsenic dissolved in any form, arseniuretted-hydrogen gas is disengaged along with the hydrogen; and that if the two gases be burnt together in a fine flame, metallic arsenic is deposited on a white porcelain surface held in the flame, and oxide of arsenic if the porcelain be held immediately above it.[^[524]] The production of a brilliant mirror-like crust in the former case, and of a white powdery one in the other, constituted Marsh’s test as originally proposed; and it was at first conceived to furnish unimpeachable evidence of the detection of arsenic. Afterwards many inquirers, and among them the discoverer himself, became satisfied that certain fallacies stand in the way of a conclusion based on such simple premises. Various supplementary tests were in consequence proposed. And at length it seems to be agreed, that the proper mode of applying Marsh’s discovery is to employ a succession of tests, of which that originally pointed out by him is the first. A vast variety of methods of analysis founded on this principle have been proposed by British and continental chemists. It would be tedious and unprofitable to discuss or even to state them here. The reader will probably be satisfied with a reference to the most important of them[^[525]] and with a description of that process, which appears to me, from repeated trials in medico-legal practice, to be at once most convenient, delicate, and conclusive.

Let the liquid to be examined be introduced into a Döbereiner’s lamp [Fig. 10], or an apparatus constructed with a bottle and a funnel upon the same principle [Fig. 11]; and dilute the liquid with distilled water, until the lower cavity of the apparatus be nearly full, leaving space however for the tube of the funnel, a fragment of zinc, and some sulphuric acid. Put in a cylinder or rod of zinc, a; and then add sulphuric acid until a moderate effervescence ensue. Close the junction of the two vessels, and then, allowing a little gas to escape at c, shut the stop-cock, and let the gas fill the vessel A, by driving the liquid up into B. Having meanwhile fitted by a cork to the exit-tube, c, the glass tube, d e, which is loosely stuffed with raw cotton at the end d g, and has a bent plate of copper or tinned iron hung over it at f,—open the stop-cock, allow a little gas to escape so as to expel the air in d e, and then kindle the gas at e, which must be contracted to a capillary opening. Keep the flame low, and hold the surface of a white porcelain vessel across the middle of it for a few seconds. If no stain be produced on the porcelain, there is no arsenic in the fluid. If a stain be formed, regulate the escape of gas by the stop-cock so that the fluid may not rise above the middle of the lower vessel of the apparatus, and apply the heat of a spirit-lamp flame to the tube d e on the left hand of the plate f, the purpose of which is to prevent the heat being communicated beyond that point. By and by, if there be arsenic in the fluid, a brilliant metallic ring will appear beyond f, owing to decomposition of arseniuretted-hydrogen gas. As soon as the crust is thick enough to present its properties characteristically, withdraw the spirit-lamp; place the tube e h so that the flame at e shall be completely within the ball, i; let the tube incline very slightly in the direction from k to l; and allow a stream of cold water to trickle down upon the portion k l, which should be wrapped in a single layer of calico. Oxide of arsenic will gradually condense, partly in white powder or minute sparkling crystals in the ball and between i and k, and partly between k and l in the form of a solution, which collects at the bend l. The solution which may be increased in quantity by boiling a little distilled water upon the powder in the ball and bend i k, is then to be subjected in small portions to the three liquid reagents, ammoniacal nitrate of silver, ammoniacal sulphate of copper, and hydrosulphuric acid.

Some experience is required to apply this process successfully. But with due attention it furnishes conclusive evidence with great delicacy and precision. A solution containing only a millionth part of oxide of arsenic will part with it readily in the form of arseniuretted-hydrogen; and the slightest trace of that gas in the hydrogen is indicated by the method recommended above.—The process is compounded of Mr. Marsh’s original discovery, the supplementary test of reduction in the exit-tube recommended by Berzelius,[^[526]] and the formation and examination of the oxide proposed by myself.[^[527]]—With certain precautions and modes of manipulating, it is applicable to the most complex organic fluids, as well as to simple solutions.

The discovery of Mr. Marsh had not been long made before the test in its original simple form was found liable to divers important fallacies. It appeared, for example, that antimony yields very nearly the same appearance of metallic crust and of white powder, according to the position of the porcelain in the flame; that some porcelains glazed with oxide of zinc are similarly stained by a flame of simple hydrogen gas; that a great variety of metallic salts, if spirted up into the exit-tube, undergo reduction in the flame, and cause imitative stains on the porcelain; that iron-salts seems to form stains from the same chemical action as what occurs in the case of arsenic; and that certain compounds of phosphorous acid with ammonia and animal matter, or even mere animal matters themselves, will in some circumstances produce a stain more or less similar to that which is occasioned by arsenic.

There is no doubt, that the resemblance of most of these spurious stains to an arsenical crust has been much exaggerated. But still the similarity is sufficient to satisfy every impartial judge, that the mere production of a brilliant metallic, or white powdery stain, or both, upon porcelain, is not conclusive evidence of the detection of arsenic in medico-legal inquiries. It is strong presumptive evidence; and the non-production of such stains is absolute proof that arsenic is not present. But in order to obtain irrefragable proof of its presence, the substance which forms the crusts and stains must be subjected to farther examination. And such is the object of the supplementary methods in the process detailed above. That process is perfectly free of fallacy. No substance yet known but arsenic can yield the succession of phenomena which have been detailed. My opinion farther is, that the process may be safely simplified by withdrawing Berzelius’s supplementary test of reduction in the exit-tube, and retaining the test of oxidation only, with the examination of the oxide by liquid reagents. I have retained the former in deference to the opinion expressed by a committee appointed by the French Institute, who examined the whole subject with unwearied zeal, but who, it may be observed, seem never to have had in their view the check-test of oxidation; which, with the consecutive tests, is superior in conclusiveness to the check of reduction only.

Reinsch’s process, like the former, has been inconveniently called a new test for arsenic. The fact discovered by Dr. Reinsch is valueless as supplying a mere test; but it forms the ground-work of the best process of all yet proposed for the detection of arsenic in solution. The discovery is, that arsenic in solution is deposited in the metallic state upon copper-leaf, when the fluid is acidulated with hydrochloric acid, and heated till it boils gently or is about to do so; and that by heating the copper gently in a glass tube the arsenic is sublimed from it in the form of oxide or metal according to the quantity present.[^[528]]

This method is so simple and easy as scarcely to require any detailed explanation. The fluid should contain about a tenth of its volume of hydrochloric acid. It must be heated near ebullition before the copper is introduced, otherwise the copper becomes tarnished, though arsenic be not present. Copper-leaf, or copper-plate worn thin by the action of diluted nitric acid, or fine copper gauze, is the best form for use. In the feeblest solutions ten or fifteen minutes elapse before arsenic is visibly deposited, and forty minutes should be allowed for strong deposition; but in strong solutions, the action takes place in a few seconds. The result is a thin, brittle brilliant, steel like coating of metallic arsenic. As soon as the deposit is formed, the copper is to be removed, dried with a gentle heat, cut into small shreds, and heated with a spirit-lamp in the smallest glass tube that will conveniently contain the whole; upon which a metallic ring of arsenic is sometimes sublimed, but more generally a ring of small sparkling crystals. These are first to be examined as to their form with a common pocket lens; and then dissolved in boiling distilled water, after shaking out the copper, so that a solution may be obtained and subjected to the liquid reagents, especially the ammoniacal nitrate of silver as being the readiest and most delicate. In all medico-legal inquiries it is necessary to perform a preliminary experiment with distilled water and the hydrochloric acid used, lest the acid contain arsenic.

The process here described is one which I have followed with great facility, certainty and despatch in several medico-legal cases.[^[529]] It is extremely delicate; for it will detect at least a 250,000th part of arsenic in solution; and it removes from the fluid every particle of arsenic, because none can be afterwards discovered by means even of Marsh’s method. It is not subject to any fallacy. The mere formation of a brilliant coating on the copper is not evidence of arsenic being present; for as Reinsch himself ascertained, solutions of bismuth, tin, zinc, and antimony produce a coating more or less similar to an arsenical one. But the farther steps of the process entirely put aside all these sources of error. The non-formation of a metallic tarnish of copper, however, is perhaps not absolute proof of the absence of arsenic. For, according to a late statement by Drs. Fresenius and Von Babo,[^[530]] “all nitrates, and various salts of mercury and other metals, render the separation of arsenic by copper difficult or even impossible.” The authors of this objection, although the paper is otherwise elaborate and detailed, have not given any particulars in illustration of so important a criticism.

Of the Tests for Oxide of Arsenic in Organic Mixtures.

The present is by far the most important of the conditions under which it may be necessary to search for arsenic in medico-legal cases; for in nine cases out of ten the subject of analysis is either some article of food or drink, the contents or tissues of the stomach, or the textures of other organs of the body into which the poison has been carried by absorption.

Accordingly much attention has been paid to this subject for some years past, and many valuable methods of analysis have been suggested, more especially since the recent discovery that arsenic, like many other poisons, undergo absorption, and is diffused by the circulation throughout the body generally. It was proved by me in 1824,[^[531]] that the tests for arsenic, at that time in general use, are so fallacious when applied to complex organic mixtures as to be unfit for medico-legal investigations except merely as trial-tests; and a process was proposed, which has since undergone various modifications from others as well as myself. This process, in the form in which it was adopted in the last edition of the present work, is still applicable to a great proportion of cases; and indeed a recent modification of it has been thought by Drs. Fresenius and von Babo to be superior even yet to every other in all circumstances.[^[532]] But two new methods are at present generally preferred, and probably not without reason. At least they have been much employed and with great success in numerous medico-legal researches, where the quantity of arsenic was to all appearance extremely small, and the subject of examination most complex and troublesome to bring within the sphere of analysis. And in particular they have been successfully employed to detect arsenic in those organs of the human body into which it can obtain admission only through the medium of absorption.

In the following statement I shall describe four processes only, that of Reinsch, by which the arsenic is first separated as a crust on copper,—that of Marsh, who first detaches it in the form of arseniuretted-hydrogen,—my own method, which consists in obtaining in the first instance a sulphuret of arsenic,—and that of Drs. Fresenius and von Babo, which has the same foundation.

Process of Reinsch.—This is the simplest and easiest of all. Remove in the first place any white or gray powder which can be detached from the mixture; and either subject it to the process of reduction by charcoal or soda-flux, as described at p. [203], or dissolve it in boiling distilled water and subject the solution to the three liquid reagents, p. [207], or if there be enough, examine it in both ways. If arsenic be thus obtained, it is seldom necessary to proceed any farther. But if not, cut all soft solids into small fragments, add distilled water if necessary, then add hydrochloric acid to the amount of a tenth of the whole mixture, and more if the subject of analysis be decayed and ammoniacal, so that there may be a decided excess of acid. Boil gently for an hour, or until all soft solids be either dissolved or broken down into fine flakes and grains. Filter through calico; bring the filtered fluid again to the boiling point; and then proceed as described for Reinsch’s method in simple arsenical solutions [p. [214]].

The only important precaution to be attended to in employing this process is to take care that the water, hydrochloric acid, and calico are free of accidental impregnation with arsenic. This is guarded against by applying the process to them in the first instance. I have lately employed this method of analysis with success in two medico-legal cases where the bodies had been buried for several months, and where the quantity of arsenic must have been very minute. Satisfactory evidence was obtained from a sixth part of the stomach, and also from the same proportion of the liver.

Process of Marsh.—The chief difficulties in applying the process of Marsh to complex organic mixtures arise from the tendency of oxide of arsenic to adhere with obstinacy to some organic principles in the solid state, and from the liability of the gas disengaged in the apparatus to raise organic fluids in a fine froth, which breaks up slowly, and is therefore apt to pass over into the exit-tube. Many contrivances have been devised, to meet these difficulties, especially by the French chemists and toxicologists, whose attention was turned earnestly to the subject by the investigations carried on in certain late criminal trials of great interest and importance. The various devices now alluded to were subjected to trial in 1841 by a Committee of the French Institute; who came to the opinion that the following method suggested by MM. Flandin and Danger is the most convenient and comprehensive.[^[533]]

Heat the organic matter with a sixth of its weight of strong sulphuric acid; when complete solution has taken place, concentrate the fluid to a friable almost dry charcoal; add a little concentrated nitric acid gradually to this when cold, and again evaporate to dryness; then act on the residue with boiling distilled water, and a solution of a reddish-brown colour is obtained, which may be used in such an apparatus as that of Döbereiner without risk of obstruction from froth.—The arseniuretted-hydrogen, thus disengaged along with the hydrogen gas, is to be submitted to the succession of tests described in speaking of Marsh’s process for detecting arsenic in a state of simple solution [p. [212]].

This method of investigation is exceedingly precise and conclusive. The sulphuric acid aided by heat destroys organic matter sufficiently to prevent frothing in the apparatus and dissolves out arsenic from a state of combination with organic principles; and nitric acid afterwards converts any arsenic in the half-charred mass into the soluble arsenic acid. It has been employed with success in various medico-legal proceedings in France. It answers well for detecting oxide of arsenic in the viscera, muscles, and other parts of the body into which the poison has been conveyed through absorption.

Process by Hydrosulphuric Acid.—This method may be employed in two ways, according as the object is merely to prove the presence of oxide of arsenic, or to ascertain also its quantity.

a. If proof of its presence be all that is wanted, cut any soft solids into small pieces, add distilled water if necessary, boil for half an hour, let the decoction cool, and filter it. Add a little acetic acid to the filtered fluid, and if any precipitate form, filter again. Evaporate to dryness, first by ebullition, afterwards over the vapour-bath. Dissolve the residuum again in repeated portions of boiling distilled water, and filter the solution. If it be not acid to litmus-paper add more acetic acid, and transmit hydrosulphuric acid gas through the fluid until an excess be indicated by the sense of smell after agitation, Then expel the excess of gas by boiling; and if the precipitate of sulphuret of arsenic do not subside readily add a little of a strong solution of hydrochlorate of ammonia, which will facilitate subsidence. When the precipitate has fallen to the bottom, withdraw the supernatant fluid with the pipette, Fig. 8; and replace it with a little boiling distilled water. Lastly, collect the precipitate on a filter, and proceed as by the reduction process with soda-flux for oxide of arsenic, in a state of simple solution.

This method answers very well for ordinary cases where the quantity of arsenic is not extremely minute. But I have met with instances in medico-legal practice where the process of Reinsch, as well as that of Marsh, succeeded in detecting the poison in sources to which the method by hydrosulphuric acid had been applied without avail; because apparently the organic matter existing in solution prevented the action of the gas, or, as Orfila thinks, because boiling water will not in all circumstances remove oxide of arsenic from the textures of the animal body which are impregnated with it. In particular I doubt whether this method is sufficiently delicate to detect arsenic in those organs and textures into which it has been conveyed in cases of poisoning through absorption into the blood.—Another objection is its tediousness. The first filtration, if the substance to be examined be the stomach or its contents, may take two days; and one way or another the analysis can seldom be completed within four days. Reinsch’s process may be brought to a conclusion in two hours or less, even in the most difficult circumstances.

b. The last process to be mentioned, is one based, like the previous one, upon the precipitation of arsenic in the form of sulphuret, but with very material modifications, the purpose of which is to enable the analyst to separate the whole arsenic in a state of purity, so as to ascertain the exact amount of the poison in the mixture. This method has been recently proposed by Drs. Fresenius and von Babo.[^[534]]

Cut any soft solids into small pieces, put the whole into a porcelain basin, add as much hydrochloric acid as equals the probable weight of the dry matter in the mixture, and then water enough to form a thin pulp. Heat the basin over the vapour-bath, adding every five minutes about half a drachm of chlorate of potass, and stirring frequently, until the liquid become clear-yellow, homogeneous, and thin. Add now two drachms more of the chlorate; filter through linen, washing the residuum on the filter with boiling water; concentrate to a pound; add a strong solution of sulphurous acid till its odour predominates, and expel the excess of it by heat. The liquid is now ready for the transmission of hydrosulphuric acid gas, which should be transmitted in a slow stream for twelve hours. Wash away any sulphuret adhering to the tube by means of ammonia, and add the solution to the principal liquid; which is next to be left at a gentle heat about 80° F., in a vessel covered with paper, till the sulphureous smell entirely disappear. The precipitate, which contains organic matter as well as sulphuret, is then to be collected on a paper filter, washed, and dried with the filter over the vapour-bath. The animal matter is next destroyed, and the sulphuret converted into arsenic acid, by dropping on it fuming nitrous acid till the whole is moistened, drying the product thoroughly over the vapour-bath, moistening the residuum with concentrated sulphuric acid, heating the mixture again in the vapour-bath for two or three hours, and raising the heat afterwards gradually in a sand-bath to 300° F., till a charred brittle mass be obtained. This is to be heated over the vapour-bath with twenty parts of distilled water, filtered, and washed with boiling water on the filter till what passes through ceases to redden litmus. The solution, which ought to be colourless, is next acidulated with hydrochloric acid, and treated as formerly with hydrosulphuric acid gas. When the sulphuret has been collected on a small filter, diluted ammonia is to be sent through the filter as long as it dissolves any sulphuret, and is to be received in a weighed porcelain basin, in which the ammonia and water are to be driven off at a temperature not exceeding 212°. The sulphuret which is alone left may now be weighed by again weighing the basin; and one grain of sulphuret is equivalent to 0·803 of a grain of oxide of arsenic.—The authors add an elaborate process for obtaining from this the whole arsenic by reduction. But such a proceeding is unnecessary. It is sufficient in medico-legal inquiries to ascertain by the simpler method given above [p. [204]], that it does yield by reduction with soda-flux a true arsenical crust, and that this yields by oxidation white, sparkling crystals with triangular facettes.

After a comparative trial of the most esteemed process, Drs. Fresenius and von Babo state that they found the one now described as delicate as any other, and the only method by which the quantity of oxide of arsenic can be ascertained with accuracy.—The hydrochloric acid used at the commencement enables the water to dissolve compounds of arsenic which water alone will not act on; and it farther facilitates solution by breaking up or dissolving organic textures. The addition of chlorate of potash prevents the escape of oxide of arsenic during the subsequent evaporation; which is apt to happen when hydrochloric acid is present. The subsequent addition of sulphuric acid converts arsenic acid into arsenious acid, in which shape the sulphuret of arsenic is more readily formed by the action of hydrosulphuric acid gas, when organic matter co-exists in the solution. The steps for destroying organic matter thrown down with the sulphuret at its first formation require no further commentary: They are the most important particulars in the process for its main object,—the determination of the quantity of pure sesqui-sulphuret, and, through it, of the sesquioxide originally in the subject of analysis.

Of certain alleged Fallacies in the case of Organic Mixtures.

Before taking leave of the detection of arsenic in organic mixtures, it is necessary to notice certain alleged fallacies in the way of every process, arising from arsenic obtaining admission into the subject of analysis through other means than its intentional addition or its introduction as a poison into the body. This topic, one of paramount importance in medico-legal chemistry, has lately undergone careful investigation during and since the notorious trial of Madame Lafarge. The results are the following:—

It has been alleged that arsenic may obtain accidental admission into the subject of analysis, 1, because the reagents used in the processes may be adulterated with arsenic; 2, because the material of the apparatus may contain it; 3, because it may have existed in antidotes administered during life; 4, because it sometimes forms a constituent part of the human body in the natural state; and 5, because it exists in the soil of some churchyards.

1. Arsenic may exist as an adulteration in some reagents.—It must be apt to occur in sulphuric acid, when that substance is prepared with pyritic sulphur, which commonly contains some sulphuret of arsenic; and it has actually been found in abundance in the acid by various experimentalists, and in England for the first time by Dr. Rees.[^[535]] It may be detected by transmitting hydrosulphuric acid gas through the diluted acid; and it may be effectually removed in the same way,[^[536]] the acid being afterwards filtered in a funnel whose throat is filled with asbestus, and the excess of gas being expelled by heat.—Hydrochloric acid may contain arsenic, because it may have been prepared with an arsenicated sulphuric acid. The impurity may be detected and removed in the same way as in that substance. Nitric acid seems not apt to be similarly adulterated;[^[537]] but it may be tested by Marsh’s process, after neutralizing the acid with potash, and adding more sulphuric acid than is required to decompose the nitre thus formed. Zinc occasionally contains a little arsenic, which will be evolved in Marsh’s process. Dr. Clark of Aberdeen says zinc is scarcely ever free of a trace of arsenic; and it has been occasionally detected by others. Orfila, however, very seldom found so much as to be discoverable by Marsh’s test applied continuously for a great length of time.[^[538]] A committee of the French Institute came to the same conclusion.[^[539]] M. Jaquelain, acting under the directions of Professor Dumas, could not detect an atom in any French specimen of zinc, or its carbonate or silicated oxide, as met with in commerce.[^[540]] Lastly, Mr. Brett satisfied himself that no British or foreign zinc he could obtain indicated the presence of arsenic by a process capable of detecting a 5000th of that metal in zinc.[^[541]] It is an obvious inference from all these inquiries that no difficulty can be experienced in obtaining zinc so pure as to exhibit not a trace of arsenic by Marsh’s method. Neither is there any difficulty in obtaining sulphuric, muriatic, and nitric acid free of that adulteration.

But at the same time it is equally obvious, that in medico-legal analyses, unless the reagents used be previously known to be free of arsenic, they ought invariably to be subjected in the first instance to the process, whatever it may be, which the analyst proposes to employ for detecting arsenic in a suspected substance.

2. Arsenic may be present in some articles of chemical apparatus.—Arsenic has been detected in the metal of cast-iron pots,[^[542]] which Orfila and others have proposed to employ in certain analyses on the large scale, as, for example, when the poison is sought for in the whole soft solids of the human body. It is denied, however, that any of that arsenic can be dissolved out of cast-iron by the process which has been followed in such circumstances.[^[543]]

The primary fact, and the qualification of it, are in my opinion of equally little medico-legal importance. It is not likely that such enormous masses of material will ever be operated on again, as those which were made use of in some late, French trials, and for which great iron pots were found indispensable;—because it has been proved that absorbed arsenic is chiefly to be met with in particular organs or secretions, such as the liver and urine. Besides, a false importance has been attached to the enthusiastic analyses of the whole human carcase, with which some French chemists have been astounding the minds of the scientific world, as well as the vulgar, on the occasion of certain late trials for poisoning. I confess I could not find fault with a jury, who might decline to put faith in the evidence of poisoning with arsenic, when the analyst, after boiling an entire body, with many gallons of water, in a huge iron cauldron, making use of whole pounds of sulphuric acid, nitric acid, and nitre, and toiling for days and weeks at the process, could do no more than produce minute traces of the poison. What man of common sense will believe, that, with such bulky materials and crude apparatus, it is possible to guard to a certainty against the accidental admission of a little arsenic? At all events I am much mistaken if any British jury would condemn a prisoner on such evidence,—or any British chemist find fault with them for declining to do so.

3. Arsenic may have existed in antidotes administered during life.—It is now generally known, that the only chemical antidote for arsenic is the hydrated sesquioxide of iron. But this substance appears occasionally to contain a little arsenic, obviously derived from the compound of iron whence the oxide is prepared.[^[544]] Such an adulteration must be rare in what is prepared by the ordinary processes, according to which the oxide of arsenic ought to remain in solution. The only effectual mode, however, of guarding against this source of error, when the antidote has been administered, is to examine a portion of the stock whence the patient was supplied, by dissolving it in an excess of sulphuric acid, and subjecting it to Marsh’s test.

4. Arsenic sometimes exists naturally in the human body.—This startling proposition was first advanced by M. Couerbe, and by Professor Orfila soon afterwards.[^[545]] The latter subsequently stated, that it exists only in the bones, and not in any of the soft solids.[^[546]] It is now clear, however, that both of these experimentalists must have committed an error. Orfila himself admits that his early researches are vitiated by the subsequent discovery of arsenic in some kinds of sulphuric acid;[^[547]] and all recent attempts by others to obtain his results have failed. Thus MM. Flandin and Danger could not detect arsenic in any part of the human body, when it had not been administered:[^[548]] Pfaff was unable to detect an atom of it in the bones of man or the lower animals by Orfila’s own process:[^[549]] Dr. Rees was equally unsuccessful:[^[550]] and in 1841 a committee of the French Institute, who superintended the performance of an analysis in three cases by Orfila, reported that he failed in every instance to find a trace of arsenic, by a process which could detect a 65th part of a grain intentionally mixed with an avoirdupois pound of bones.[^[551]]

There is the strongest possible presumption, therefore, that human bones never contain any arsenic. And besides, supposing they did, the source of fallacy would be utterly insignificant; for, when it becomes necessary to search for arsenic absorbed into the textures of the body, it is never necessary to have recourse to the bones.

5. Arsenic may exist in the soil of churchyards.—This proposition too was first announced by Professor Orfila, who found a little in the churchyard of Villey-sur-Tille, near Dijon, and of the Bicêtre, Mont-Parnasse, and New Botanic Garden at Paris.[^[552]] And although MM. Flandin and Danger afterwards denied they could ever find any,[^[553]] a committee of the Parisian Academy of Medicine reported that Orfila proved before them the accuracy of his statement.[^[554]] But the arsenic exists in a state in which it cannot be dissolved out by boiling water: It has been hitherto separable only by boiling the churchyard mould with concentrated sulphuric acid. Hence it cannot pass by percolation through a coffin into a body; and consequently it becomes a source of fallacy only when the coffin has been broken up in the course of time, and the mould lies in actual contact with the organs to be analysed.[^[555]]

It plainly appears, then, that most of the fallacies alleged against the validity of the evidence derived from the discovery of arsenic within the human body in cases of poisoning have no real existence; and that those which are real can easily be provided against by simple and obvious precautions.

3. Arsenite of Copper.

The arsenite of copper [Scheele’s-green, Mineral-green] deserves notice, because it is in use as a pigment, and has actually been used as a poison. Dr. Duncan once detected it in pills, given to a pregnant female with the view of procuring abortion; in Paris it has been detected in sweetmeats, having been used to give them a fine green colour;[^[556]] and Mr. Ainley of Bingley in Yorkshire informs me he found it to constitute a pigment sold by London pastry-cooks under the name of emerald-green for colouring preserves, and which in his practice had proved poisonous to children who had eaten apple-tarts coloured with it.

It is a compound of arsenious acid and deutoxide of copper, is sold in powder or pulverulent cakes, and has a pale grass-green colour. Its nature may be ascertained by heating it in a glass tube. Crystals of oxide of arsenic sublime, and oxide of copper remains, which, on being dissolved in nitric acid, yields a fine violet-blue solution with ammonia.

The mineral-green of the shops, however, is seldom arsenite of copper. The substance sold in Edinburgh under that name, although believed by colourmen to be a preparation of arsenic, is not the arsenite of copper, but a mixture of hydrated oxide of copper and carbonate of lime; which will be mentioned more particularly under the head of the poisons of copper.

Process for Organic Mixtures.—The suspected mixture is to be heated with a little hydrochloric acid and well stirred. The arsenite being thus dissolved, the solution is to be allowed to cool and then filtered. A stream of hydrosulphuric-acid gas will now cause a dark-brown or yellowish-brown muddiness or precipitate, which is a mixture of sulphuret of copper and sulphuret of arsenic. The precipitate being separated after boiling, and properly cleansed by the process of subsidence and affusion, or if it is large, by washing on a filter, the two sulphurets are to be separated by ammonia, which dissolves sulphuret of arsenic but leaves the sulphuret of copper; and the sulphuret of arsenic may be recovered from the filtered fluid by expelling the ammonia with heat. The sulphuret of arsenic is next to be reduced as directed at page [211]; and the sulphuret of copper examined as recommended under the head of copper.

4. Arsenite of Potass.

This salt is an object of some importance to the medical jurist, as it forms the basis of a common medicine, Fowler’s Solution, or the Tasteless Ague Drop. This preparation contains in every ounce four grains of arsenious acid. It has a brownish-red colour, and an odour of lavender. It is strongly alkaline to litmus. When acidulated with hydrochloric acid, hydrosulphuric-acid gas causes in it a dirty brownish-yellow precipitate; and Reinsch’s process will detach arsenic from it upon copper in a state capable of being subjected to the usual tests [see p. [214]].

5. Arseniate of Potass.

This substance is so rarely met with as to be an object of little consequence to the medical jurist: nevertheless I have found in the course of reading two instances of poisoning with it. A very dangerous and tedious case has been related by Professor Bernt, which arose from too great a quantity having been given medicinally by an ignorant druggist;[^[557]] and a case of accidental poisoning with it has been related in the London Medical Repository.[^[558]] A singular account too has been published of the accidental poisoning of seven horses with it at Paris. They all died, most of them with the symptoms and morbid appearances of well-marked inflammation of the alimentary canal.[^[559]]

When solid it forms tetraedral prismatic crystals, acuminated by four planes. It is very soluble in water, fuses at a red heat, and on cooling concretes into a crumbly, foliaceous mass, having a pearly lustre. It is easily known by the effect of the process of reduction—of the nitrate of silver, the salts of copper, and sulphuretted-hydrogen. Heated with charcoal in a tube it gives off metallic arsenic in the usual manner; but a stronger heat is required than for the reduction of the arsenious acid. Dissolved in water and treated with nitrate of silver it yields a brick-red precipitate, the arseniate of silver. With the salts of copper its solution gives a pale bluish-white precipitate, the arseniate of copper. With sulphuretted-hydrogen gas, preceded by acidulation with muriatic acid, and transmitted for a considerable length of time, it yields the yellow sulphuret of arsenic. When in solution it yields arsenic both by Reinsch’s process and the method of Marsh.

6. The Sulphurets of Arsenic.

In the arts various substances are known which contain a compound of sulphur and arsenic. In the first place, two pure sulphurets are known in chemistry and in painting, the one of a fine orange colour, and known by the name of realgar, the other of a rich sulphur-yellow, and termed orpiment. Secondly, the name of orpiment is familiarly given to a pigment in more general use than either of the former, which has a less lively colour, and consists of pure orpiment with a large admixture of arsenious acid. Lastly, orpiment also forms a great proportion of another common pigment, King’s yellow.

The orange-red sulphuret (realgar, risigallum, Σανδαραχη, sandaracha), is chiefly a natural production. It is solid, of a bright orange-red colour, and composed of small shining scales, so soft as to be scratched with the nail. It is composed of one equivalent of metal and one of sulphur. Its best chemical characters are the disengagement of metallic arsenic when it is heated in a tube with potass or the black flux; and its undergoing sublimation unchanged when heated alone in a tube.

The yellow sulphuret (orpiment, auripigmentum, αρσενικον), is both a natural production, and the result of many chemical operations. The sulphuret thrown down from solutions of arsenic by sulphuretted-hydrogen is quite conformable in physical and chemical characters with the natural orpiment. Natural orpiment, when in mass, consists of broad scales of much brilliancy and of a rich yellow colour. It is composed of two equivalents of metal and three of sulphur. Its most striking chemical characters are the same with those of realgar, from which it is distinguished chiefly by its colour.

It has been stated by Hahnemann in his elaborate work on Arsenic, that the pure sulphurets are somewhat soluble in water,—that native orpiment is soluble in 5000 parts of water with the aid of ebullition, and that artificial orpiment by precipitation is soluble in 600 parts.[^[560]] Hahnemann, however, was mistaken in supposing that the water dissolved these sulphurets. It does not dissolve, but decomposes them. Very lately M. Decourdemanche has found that, by slow action in cold water, and much more quickly with the aid of heat, the arsenical sulphuret is decomposed by virtue of a simultaneous decomposition of the water, hydrosulphuric acid being evolved and an oxide of arsenic remaining in solution. And he has farther remarked, that this change is promoted by the presence of animal and vegetable principles dissolved in water.[^[561]] These facts are interesting, as they explain certain apparent anomalies to be noticed presently in the physiological properties of the sulphurets.

The common orpiment of the shops is not a pure sulphuret like the natural orpiment, but a much more active substance, a mixture of orpiment and arsenious acid. It is made by subliming in close vessels a mixture of sulphur and oxide of arsenic. It is met with in the shops in two forms, in that of a fine powder possessing a yellow colour with a faint tint of orange, and in that of concave masses composed of layers of various tints of white, yellow and orange, commonly also lined internally with tetraedral white pyramidal crystals. Till lately it was accounted a variety of sulphuret, and some ingenious conjectures were made as to the cause of its superior energy over the other sulphurets as a poison. But M. Guibourt has proved that it always contains oxide of arsenic, and is commonly impregnated with it to a very large amount, some parcels containing so much as 96 per cent.[^[562]] The inner surface I have often seen lined with large crystals of pure oxide. In a very interesting account by Dr. Symonds of Bristol, describing the case of Mrs. Smith, for whose murder a woman Burdock was executed in that city a few years ago, it is stated that artificial orpiment was the poison given, that death took place in a very few hours, and that a sample from the druggist’s shop where the poison was bought contained on an average 79 per cent. of oxide of arsenic.[^[563]]

Another impure sulphuret, a good deal used in painting, and a favourite poison in this country for killing flies, is King’s yellow. It is sold in the form of a light powder or in loose conical cakes. It has an intense sulphur-yellow colour. This substance is soluble, though not entirely, in water, both cold and warm, and forms a colourless solution, from which, on cooling, or by evaporation, a yellow powder separates. In this respect it differs essentially from the pure sulphurets. The solution is not acted on by reagents in the same way as the solution of arsenious acid. Lime-water and hydrosulphuric acid have no effect on it, the ammoniacal nitrate of silver causes a copious dirty brown, and the ammoniacal sulphate of copper a scanty, dirty lemon-yellow precipitate. I have not seen any account of the mode of preparing it or an analysis of its composition. But according to my own experiments it contains a large proportion of sulphuret of arsenic, a considerable proportion of lime, and about 16 per cent. of sulphur. Its nature is best shown by the following method of analysis. Let the powder be agitated in diluted ammonia till the colour becomes white. The filtered fluid contains the sulphuret of arsenic, which, on addition of an acid, falls down, and may be separated and reduced in a tube with the black flux. The remaining white powder, well freed from adhering sulphuret by washing, is next to be agitated in diluted acetate or hydrochloric acid and again filtered. The solution on being neutralized precipitates abundantly with oxalate of ammonia and the alkaline carbonates, showing that lime was taken up by the acid: and, as the acid operates without effervescence, the lime must have been in the caustic state. The powder which remains after the action of the acid will be found to fuse with a gentle heat and to burn almost entirely away with a blue flame, emitting sulphureous vapours. These experiments make it obvious that King’s yellow contains sulphuret of arsenic, caustic lime, and free sulphur; and in all probability the lime exists in the form of a triple sulphuret of lime and arsenic.

All the preparations containing the sulphuret of arsenic are interesting to the medical jurist, but particularly the two impure sulphurets last mentioned. The King’s yellow above all should be carefully studied, because on account of its frequent employment as a fly-poison it has been the source of fatal accidents. It was likewise taken intentionally a few years ago in this city, and proved fatal in thirty-six hours. Dr. Duncan also, while he was Professor of Medical Jurisprudence, met with an instance of an attempt to poison by mixing King’s yellow with tea; and at the Glasgow Spring Circuit of 1822 a woman was tried for poisoning her child with it.

Process for Organic Mixtures.—If sulphuret of arsenic be present in such mixtures in appreciable quantity, the particles, owing to their intense yellow colour, will be visible in any mass which has not the same tint. From this state of admixture they may be removed by adding caustic ammonia which dissolves sulphuret of arsenic; and the solution, on being acidulated with muriatic acid, will deposit the sulphuret sufficiently pure for undergoing the process of reduction.

Sulphuret of arsenic sometimes exists in small quantity in the stomach, although the poison was given in the form of oxide; for a portion of the oxide is subject to be converted into the sulphuret by hydrosulphuric acid gas evolved in the stomach after death.[^[564]] In every instance of the kind yet carefully examined a large proportion of the oxide has remained unacted on, although the intense colour of the mixed sulphuret makes it appear as if that were the only compound present.

7. Arseniuretted-Hydrogen.

This compound presents the form of a colourless gas, possessing a fetid garlicky odour, a density of nearly 2·7, and great virulence as a poison. It is mentioned here, because accidental poisoning with it has happened occasionally within a few years, chiefly owing to the occasional adulteration of sulphuric acid with arsenic, and the liability of the arsenic to form arseniuretted-hydrogen when such sulphuric acid is used to prepare hydrogen gas. Dr. O’Reilly has mentioned a melancholy instance of a young chemist losing his life in this way.[^[565]] Dr. Schlinder of Greifenberg has related another, which did not prove fatal.[^[566]] And it is well known that the German chemist Gehlen lost his life by accidentally breathing arseniuretted-hydrogen while engaged in examining its chemical properties.[^[567]] It is an inflammable body; and its presence in any other gas is easily detected by burning it according to the method of Marsh.

Section II.—Of the Action of Arsenic and the Symptoms it excites in Man.

It is now generally admitted that arsenic produces in the living body two classes of phenomena,—or that, like the narcotico-acrids, it has a twofold action. One action is purely irritant, by virtue of which it induces inflammation in the alimentary canal and elsewhere. The other, although it seldom occasions symptoms of narcotism properly so called, yet obviously consists in a disorder of parts or organs remote from the seat of its application.

It is also the general opinion of toxicologists, that arsenic occasions death more frequently through means of its remote effects than in consequence of the local inflammation it excites. In some cases indeed no symptoms of inflammation occur at all; and in many, although inflammation is obviously produced, death takes place long before it has had time to cause material organic injury. Nevertheless in some, though certainly in comparatively few instances, the local action, it must be admitted, predominates so much, that the morbid changes of the part primarily acted on are alone adequate to account for death.

Its chief operation being on organs remote from the part to which it is applied, a natural object of inquiry is, whether this action results from the poison entering the blood, and so passing to the remote organs acted on, or simply arises from the organ remotely affected sympathizing through the medium of the nerves with the impression made on the organ which is affected primarily. On this question precise experiments are still wanted. The general opinion has for some time been that it acts through the blood. And this view has of late been strengthened by indisputable evidence, that the poison does enter the blood, and is diffused by it throughout the body.

For a long period chemists sought in vain for arsenic in the animal tissues and secretions at a distance from the alimentary canal. Such was the position of matters at the date of the last edition of this work; in which the failure was ascribed to the methods of analysis then known not being delicate enough to discover the small quantity of arsenic which disappears by absorption in cases of poisoning.[^[568]] That statement is now referred to, because in a late controversy in France an attempt was made, by an erroneous quotation of this work, to deprive Professor Orfila of the honour, which is due to him alone, of having recently been the first to demonstrate the possibility of detecting arsenic throughout the organs and secretions generally of the bodies of men and animals poisoned with it.

This most important discovery, pregnant alike with interesting physiological deductions and valuable medico-legal applications, was first announced by him to the Parisian Academy of Medicine in January, 1839; when he stated that arsenic is absorbed in such quantity in cases of poisoning as to admit of being discovered by an improved process of analysis in various organs and fluids of the body, such as the liver, spleen, kidneys, muscles, blood, and urine.[^[569]] In November, 1840, he proved these facts to the satisfaction of a committee of the academy.[^[570]] And since then they have been confirmed by others, not merely in express experiments, but likewise in the familiar experience of medico-legal practice. The situations where arsenic is met with in largest quantity are the liver, the spleen, and the urine, but above all the liver. The precise circumstances in which it may be found in one or another of these quarters have not yet been determined. But in most cases of acute arsenical poisoning where the search has been made at all, it has proved successful in the liver. In two late instances I have readily found arsenic by the process of Marsh or Reinsch in the liver after four months’ interment.

Since arsenic then is clearly absorbed into the blood, it becomes an interesting question whether the organization of the blood is thereby changed. This question cannot be answered with confidence. But in all probability the blood does undergo some change in its crasis; for in most cases of acute poisoning that fluid is found after death in a remarkable state of fluidity [see Section on the Morbid Appearances]; and Mr. James observed that if venous or arterial blood be received into a solution of arsenic, instead of coagulating in the usual way, a viscous jelly first forms, and lumpy clots separate afterwards.[^[571]]

Our knowledge of the affection induced by the remote action of arsenic is in some respects vague. Toxicologists have for the most part been satisfied with calling it a disorder of the general nervous system. When employed to designate the state of collapse which accompanies or forms the chief feature of acute cases of poisoning with arsenic, this term is misapplied. The whole train of symptoms is that not of a general nervous disorder, but simply of depressed action of the heart. That this is the chief organ remotely acted on in such cases farther appears probable from certain physiological experiments, in which it has been remarked, that immediately after rapid death from arsenic the irritability of the heart was exhausted or nearly so, while that of the intestines, gullet, and voluntary muscles continued as usual.[^[572]] As to the singular symptoms which often arise in the advanced stage of lingering cases, the term, disorder of the general nervous system, is more appropriately applied to them. They clearly indicate a deranged state sometimes of the brain, sometimes of particular nerves.

Arsenic belongs to those poisons which act with nearly the same energy whatever be the organ or texture to which they are applied. The experiments of Sproegel,[^[573]] repeated by Jaeger,[^[574]] and by Sir Benjamin Brodie,[^[575]] leave no doubt, that when applied to a fresh wound it acts with at least equal rapidity as when swallowed. Although in such circumstances the signs of irritation are often distinct, yet the symptoms are on the other hand sometimes more purely narcotic than by any other mode of administering it,—Sir B. Brodie in particular having observed loss of sense and motion to be induced, along with occasional convulsions. Arsenic likewise acts with energy when applied to the conjunctiva of the eye, as was proved by Dr. Campbell. It acts too with great energy when inhaled in the state of vapour into the lungs, or in the form of arseniuretted-hydrogen. It farther acts with violence through the mucous membrane of the vagina, producing local inflammation, and the usual constitutional collapse. These facts were determined experimentally by the Medical Inspectors of Copenhagen on the occasion of a singular trial which will be noticed afterwards. Arsenic also acts, as may easily be conceived, when injected into the rectum. And farther, it acts as a poison, when it is applied to the surface of ulcers, yet certainly not under all circumstances. Its power of acting through the unbroken skin has been questioned. Jaeger found that, when it was merely applied and not rubbed on the skin of animals, it had no effect.[^[576]] But some cases will be afterwards mentioned which tend to show that the reverse probably holds in regard to man. According to the last-mentioned author, who is the only experimentalist that has hitherto examined the subject consecutively, arsenic is most active when injected into a vein, or applied to a fresh wound, or introduced into the sac of the peritonæum; it is less powerful when taken into the stomach; it is still less energetic when introduced into the rectum; and it is quite inert when applied to the nerves.

It is a striking fact in the action of that poison that, whatever be the texture in the body to which it is applied, provided death do not ensue quickly, it almost always produces symptoms of inflammation in the stomach; and on inspection after death traces of inflammation are found in that organ. In some instances of death caused by its outward application, the inflamed appearance of the stomach has been greater than in many cases where it had been swallowed. Sproegel met with a good example of this in a dog killed by a drachm applied to wounds. The whole stomach and intestines, outwardly and inwardly, were of a deep-red colour, blood was extravasated between the membranes, and clots were even found in the stomach.[^[577]]

Of the different preparations of arsenic, it may be said in general terms, that those are most active which are most soluble. In conformity with what appears to be a general law in toxicology, the metal itself is inert. It is difficult to put this fairly to the test, because it is not easy to pulverize the metal without a sufficient quantity being oxidated to cause poisonous effects. Bayen and Deyeux, however, found that a drachm carefully prepared might be given in fragments to dogs without injuring them; and they once gave a cat half an ounce without any other consequence than temporary loss of flesh.[^[578]] Its alloys are also inert. The same experimentalists found it inactive when combined with tin; and Renault likewise found it inactive when united with sulphur and iron in the ore mispickel, or arsenical pyrites.[^[579]]

It is probable that all the other preparations of arsenic are more or less deleterious.

A difference of opinion prevails as to the power of the sulphurets. Various statements have been published on the subject. But it may be sufficient to observe, that in consequence of the poisonous properties of the sulphurets having been imputed to the oxide, with which they are often adulterated,—Professor Orfila made some experiments with native orpiment and realgar, and with the sulphuret procured by sulphuretted-hydrogen gas (which are all pure sulphurets); and he found that in doses varying from 40 to 70 grains they all caused death in two, three, or six days, whether they were applied to a wound, or introduced into the stomach.[^[580]] It may appear at first view singular that the sulphurets, being insoluble, should be poisonous; but the apparent anomaly vanishes on considering the experiments of M. Decourdemanche formerly noticed; which prove that in animal fluids the sulphurets are rapidly changed into the oxide (see p. [225]). The sulphurets, however, are much less active than the preparations in which the metal exists already oxidated. Yet in sufficient doses they will prove rapidly fatal. In the Acta Germanica there is the case of a woman who was killed in a few hours by realgar, mixed by her step-daughter in red cabbage soup.[^[581]] The common artificial orpiment procured by sublimation is very active, in consequence of the oxide mixed with it. Renault found three grains killed a dog in nine hours.[^[582]]

Among the less active preparations of arsenic may also be enumerated such of the arsenites and arseniates as are not soluble in water. They have not indeed been actually tried. But there can be little doubt that they will prove poisonous; because, though insoluble in water, they are probably somewhat soluble in the animal juices. We may infer from their sparing solubility, even in these menstrua, that they will be less active than the preparations now to be mentioned, which are more soluble.

These are the alkaline arsenites and arseniates, arsenic acid, arsenious acid, the black oxide or fly-powder, and arseniuretted-hydrogen. With regard to arsenic acid, and the alkaline arseniates and arsenites, it is probable, from their effects in medicinal doses, that they are as active as the white oxide, if not more so. But they have not been particularly examined, as they are not objects of great interest to the medical jurist.

The fly-powder or black oxide is very active. Renault found that four grains killed a middle-sized dog in ten hours.[^[583]] It has been likewise known to prove quickly fatal to man. In a French journal there is a case related which ended fatally in sixteen hours;[^[584]] and in the Acta Germanica is an account of four persons, who died in consequence of eating a dish of stewed pears poisoned with it, and of whom three died within eighteen hours.[^[585]] The dose is not mentioned; but it is probable from the collateral circumstances that it was not considerable.

Arseniuretted-hydrogen is probably the most active of all arsenical compounds. The celebrated German chemist Gehlen, having accidentally inhaled a small portion of it, died in nine days with the usual symptoms of arsenical poisoning. In Dr. O’Reilly’s case, which proved fatal in seven days, it was computed that the equivalent of twelve grains of oxide had been inhaled. And Dr. Schlinder’s patient had inhaled a quantity of gas corresponding with only an eighth of a grain of sesquioxide; yet he appears to have made a narrow escape.[^[586]]

It is of some consequence to settle with precision the power of the white oxide. Witnesses are often asked on trials how small a quantity will occasion death? It is obvious that this question admits only of a vague answer: It can be answered at all only in reference to concomitant circumstances, and even then but presumptively. Nevertheless, it is right to be aware what facts are known on the subject.

It has been stated by various systematic authors that the white oxide will prove fatal to man in the dose of two grains. Hahnemann says in more special terms, that in circumstances favourable to its action four grains may cause death within twenty-four hours, and one or two grains in a few days.[^[587]] But neither he nor any of the other authors alluded to have referred to actual cases. Foderé knew half a grain cause colic pains in the stomach and dysenteric flux, which continued obstinately for eight days;[^[588]] and I have related an instance where six persons, after taking each a grain in wine during dinner, were seriously and violently affected for twelve hours.[^[589]] Mr. Alfred Taylor mentions three similar cases occasioned by arsenic accidentally taken in port wine after dinner,—one, an infant of sixteen months who got about a third of a grain, another, a lady who took a grain and a half, and the third, a gentleman, who had two grains and a half,—in all of whom violent vomiting, and prostration, without pain, occurred for three or four hours; and the gentleman of the party did not recover for several days.[^[590]] M. Lachèse mentions his having met with a number of cases of poisoning from small doses taken in bread or soup; whence he concludes, that an eighth of a grain taken in food may cause vomiting;—that a quarter of a grain or twice as much taken once only causes vomiting, colic, and prostration,—that the same quantity repeated next day renews these symptoms in such force as to render the individual unfit for work till three or four days afterwards,—and that four such doses, taken at intervals during two days, that is between one and a half and two grains in all, excite acute gastro-enteritis and may prove fatal, since two individuals who had taken this much died, one in seven weeks, the other three weeks later.[^[591]] The smallest fatal dose I have found recorded elsewhere is four grains and a half; and death ensued in six hours only.[^[592]] But the subject was a child, four years old, and the poison was taken in solution. Alberti mentions the case of a man who died from taking six grains; but I am unacquainted with the particulars, not having seen the original account.[^[593]] Two children, whose cases are alluded to in the Proceedings of the Academy of Medicine of Paris, died, the one in two days, the other a day later, after taking rather less than sixteen grains. The former was four years and a half old, the latter seven years.[^[594]] Valentini alludes to a case where thirty grains of the oxide in powder killed an adult in six days.[^[595]] The effects of medicinal doses, which seldom exceed a quarter of a grain without causing irritation of the stomach, and the fatal effects of somewhat larger doses on animals, Renault having found that a single grain in solution killed a large dog in four hours,[^[596]] must convince every one that the general statement of Hahnemann cannot be very wide of the truth. Mr. Taylor thinks his own cases mentioned above throw doubt over this inference. But it must be remembered, that his patients had dined just before taking the poison.

It is not improbable that the activity of oxide of arsenic is impaired by admixture with other insoluble powders. M. Bertrand, conceiving from some experiments on animals that he had found an antidote for arsenic in charcoal powder, took no less than five grains of the oxide mixed with that substance, and he did not suffer any injury, although his stomach was empty at the time, and he did not vomit.[^[597]] But Orfila afterwards showed, that other insoluble powders, such as clay, have the same effect; that no such powder can be of any use if not introduced into the stomach till after the arsenic is swallowed; and that they appear to act solely by enveloping the arsenical powder and preventing it from touching the membrane of the alimentary canal.[^[598]] Although M. Bertrand’s discovery will not supply the physician with an antidote, the medical jurist will not lose sight of the interesting fact, that, by certain mechanical admixtures, arsenic in moderate doses may be entirely deprived of its poisonous quality. A singular case of recovery from no less a dose than sixty grains, which happened in the case of an American physician, probably comes under the same head with the experiments of Bertrand,—a large quantity of powder of cinchona-bark having been swallowed along with the arsenic. In this case, however, the symptoms were severe for three days.[^[599]]

The tendency of habit to modify the action of arsenic is questionable. So far as authentic facts go, habit has no power of familiarizing the constitution to its use. One no doubt may hear now and then of mountebanks who swallow without injury entire scruples or drachms of arsenic, and vague accounts have reached me of patients who took unusually large doses for medicinal purposes. But as to facts of the former kind, it is clear that no importance can be attached to them; for it is impossible to know how much of the feat is genuine, and how much legerdemain. With respect to the latter facts, I have never been able to ascertain any precise instance of the kind; and so far as my own experience goes, the habit of taking arsenic in medicinal doses has quite an opposite effect from familiarizing the stomach to it.

Oxide of arsenic being sparingly soluble, its operation is often much influenced by the condition of the stomach as to food at the time it is swallowed. If the stomach be empty, it adheres with tenacity to the villous coat and acts with energy. If the stomach be full at the time, the first portions that come in contact with the inner membrane may cause vomiting before it can be diffused, so that the whole or greater part is discharged. One remarkable case of this nature has been quoted in page [29]. In another, where severe symptoms did supervene, and recovery was ascribed to the use of magnesia as an antidote, the favourable result seems to have been really owing to the circumstance, that the patient had supped heartily not long before taking the arsenic.[^[600]] An extraordinary case related by Mr. Kerr, in which nearly three-quarters of an ounce were retained for two hours without causing any serious mischief, probably comes under the same category; for the arsenic was taken immediately after a meal, and the stomach was cleared out by emetics.[^[601]]

In the following detail of the symptoms caused by arsenic in man, its effects when swallowed will be first noticed; and then some remarks will be added on the phenomena observed when it is introduced through other channels.

The symptoms of poisoning with arsenic may be advantageously considered under three heads. In one set of cases there are signs of violent irritation of the alimentary canal and sometimes of the other mucous membranes also, accompanied with excessive general depression, but not with distinct disorder of the nervous system. When such cases prove fatal, which they generally do, they terminate for the most part in from twenty-four hours to three days. In a second and very singular set of cases there is little sign of irritation in any part of the alimentary canal; perhaps trivial vomiting or slight pain in the stomach, but sometimes neither; the patient is chiefly or solely affected with excessive prostration of strength and frequent fainting; and death is seldom delayed beyond the fifth or sixth hour. In a third set of cases life is commonly prolonged at least six days, sometimes much longer, or recovery may even take place after a tedious illness; and the signs of inflammation in the alimentary canal are succeeded or become accompanied, about the second or fourth day or later, by symptoms of irritation in the other mucous passages, and more particularly by symptoms indicating a derangement of the nervous system, such as palsy or epilepsy. The distinctions now laid down will be found in practice to be well defined, and useful for estimating in criminal cases the weight of the evidence from symptoms.

1. In one order of cases, then, arsenic produces symptoms of irritation or inflammation along the course of the alimentary canal. Such cases are the most frequent of all. The person commonly survives twenty-four hours, seldom more than three days; but instances of the kind have sometimes proved fatal in a few hours, and others have lasted for weeks. On the whole, however, if the case is much shorter than twenty-four hours, or longer than three days, its complexion is apt to be altered. In the mildest examples of the present variety recovery takes place after a few attacks of vomiting, and slight general indisposition for a day or two.

In regard to the ordinary progress of the symptoms, the first of a decisive character are sickness and faintness. It is generally thought indeed that the first symptom is an acrid taste; but this notion has been already shown to be erroneous. For some account of the sensations felt in the act of swallowing the poison, the reader may refer to what has been stated in p. [200]. There is no doubt, that in the way in which arsenic is usually given with a criminal intent, namely, mixed with articles of food, it seldom makes any impression at all upon the senses during the act of swallowing.

In some instances the sickness and faintness, particularly when the poison was taken in solution, have begun a few minutes after it was swallowed. Thus in a case mentioned by Bernt, in which a solution of arseniate of potass was taken, the symptoms began violently in fifteen minutes;[^[602]] in one related by Wildberg, where the oxide was given in coffee, the person was affected immediately on taking the second cup;[^[603]] in one related by Mr. Edwards, the patient was taken ill in eight minutes,[^[604]] in one mentioned by M. Lachèse of Angers, violent symptoms commenced within ten minutes after the poison was swallowed with prunes;[^[605]] in a case communicated to me by Mr. J. H. Stallard of Leicester, the symptoms set in with violence ten minutes after it was taken dissolved in tea; nay, in a case of poisoning with orpiment in soup, mentioned by Valentini, the man felt unwell before he had finished his soup, and set it aside as disagreeable.[^[606]] It is a mistake therefore to suppose, as I have known some do, that arsenic never begins to operate for at least half an hour. Nevertheless it must be admitted, that in general arsenic does not act for half an hour after it is swallowed.—On the other hand, its operation is seldom delayed beyond an hour. The following, however, are exceptions to this rule. Lachèse in the paper quoted above mentions an instance where the interval was two hours, and where the issue was eventually fatal. The arsenic had been in very coarse powder. Mr. Macaulay of Leicester has communicated to me a case where the individual took the poison at eight in the evening, went to bed at half-past nine, and slept till eleven, when he awoke with slight pain in the stomach, vomiting, and cold sweats. In this instance the dose was seven drachms, and death took place in nine hours. M. Devergie has related a similar case of poisoning with the sulphuret, where the symptoms did not begin for three hours; and here too the patient fell asleep immediately after swallowing the poison.[^[607]] Professor Orfila has noticed an instance, to be quoted afterwards, where there appears to have been scarcely any symptom at all for five hours[^[608]] (p. [243]). I suspect we must also consider as an instance of the same kind the case which gave occasion to the trial of Mrs. Smith here in 1827. A white draught was administered in a suspicious manner at ten in the evening; the girl immediately went to bed; and no symptoms appeared till six next morning, from which time her illness went on uninterruptedly.[^[609]] In three of the preceding cases it will be remarked that sleep intervened between the taking of the poison and the invasion of the symptoms; and it is therefore not improbable that the reason of the retardation is the comparative inactivity of the animal system during sleep.—In voluntary poisoning, as in a case related by Dr. Roget, a slight attack of sickness or vomiting occasionally ensues immediately after solid arsenic is swallowed, and some time before the symptoms commence regularly.[^[610]]

The observations now made will often prove important for deciding accusations of poisoning; for pointed evidence may be derived from the commencement of the symptoms, after a suspected meal, corresponding or not corresponding with the interval which is known to elapse in ascertained cases. The reader will see the effect of such evidence in attaching guilt to the prisoner in the case of Margaret Wishart, which I have detailed elsewhere.[^[611]] In the trial of Mrs. Smith, the want of the correspondence just mentioned contributed greatly to her acquittal; for the symptoms of poisoning did not begin till more than eight hours after the only occasion on which the prisoner was proved to have administered any thing in a suspicious manner. As I was not at the time acquainted with any parallel case except that recorded by Orfila, I hesitated to ascribe the symptoms to the draught; and consequently, as the other medical witnesses felt the same hesitation on the same account, the proof of administration was considered to have failed. I am not sure that I should have now felt the same difficulty. The intervening state of sleep probably affords an explanation of the long interval; and the cases noticed by Mr. Macaulay and M. Devergie are parallel, though the interval in them was certainly not so great.—There is a limit, however, to the possible interval in such cases. It seems impossible that the action of the poison shall be suspended for three entire days. Yet death has been ascribed to arsenic in such circumstances. A child 3½ years old having swallowed eight grains with bread and butter, but being soon made to vomit forcibly by emetics, presented no decided symptom at the time, or for three days more; but on the fourth day difficult breathing ensued, with anxiety of expression, frequency of the pulse, and heat of the skin; and next day death took place. There was no morbid appearance found in the body.[^[612]] I do not know of any parallel instance of death from arsenic, and cannot admit that the poison was the cause of the symptoms and fatal event.

Soon after the sickness begins, or about the same time, the region of the stomach feels painful, the pain being commonly of a burning kind, and much aggravated by pressure. Violent fits of vomiting and retching then speedily ensue, especially when drink is taken. There is often also a sense of dryness, heat, and tightness in the throat, creating an incessant desire for drink; and this affection often precedes the vomiting. Occasionally it is wanting, at other times so severe as to be attended with suffocation and convulsive vomiting at the sight of fluids.[^[613]] Hoarseness and difficulty of speech are commonly combined with it. The matter vomited is greenish or yellowish; but sometimes streaked or mixed with blood, particularly when the case lasts longer than a day.

In no long time after the first illness diarrhœa generally makes its appearance, but not always. In some cases, instead of it, the patient is tormented by frequent, ineffectual calls: in others the great intestines are scarcely affected. About this time the pain in the stomach is excruciating, and is often likened by the sufferer to a fire burning within him. It likewise extends more or less downwards, particularly when the diarrhœa or tenesmus is severe; and the belly is commonly tense and tender, sometimes also swollen, though not frequently,—sometimes even on the contrary drawn in at the navel.[^[614]] When the diarrhœa is severe, the anus is commonly excoriated and affected with burning pain.[^[615]] In such cases the burning pain may extend along the whole course of the alimentary canal from the throat to the anus. Nay at times the mouth and lips are also inflamed, presenting dark specks or blisters.[^[616]]

Sometimes there are likewise present signs of irritation of the lungs and air-passages,—almost always shortness of breath (which, however, is chiefly owing to the tenderness of the belly),—often a sense of tightness across the bottom of the chest, and more rarely decided pain in the same quarter, darting also through the upper part of the chest. Sometimes pneumonia has appeared a prominent affection during life, and been distinctly traced in the dead body.[^[617]]

In many instances, too, the urinary passages are affected, the patient being harassed with frequent, painful and difficult micturition, swelling of the penis, and pain in the region of the bladder, or, if a female, with burning pain of the vagina and excoriation of the labia.[^[618]] Sometimes the irritation of the urinary organs is so great as to be attended with total suppression of urine, as in a case related by Guilbert of Montpellier, in which this symptom continued several days.[^[619]] During the late contentions among chemists, physiologists, and physicians, occasioned by the case of Madame Lafarge, it was alleged by Flandin and Danger that in animals the urine is always suppressed, by Orfila that it is always secreted, by Professor Delafond of the Alfort Veterinary School, that it is never suppressed, but always diminished, and sometimes even to a sixth of the natural quantity.[^[620]] There is, however, no invariable rule in the matter. And in fact, urinary symptoms are seldom present unless the lower bowels are likewise strongly irritated; but are then seldom altogether wanting. They are rarely well marked in cases of the present variety, unless life is prolonged three days or more.

When symptoms of irritation of the alimentary canal have subsisted a few hours, convulsive motions often occur. They commence on the trunk, afterwards extend over the whole body, are seldom violent, and generally consist of nothing else than tremors and twitches. Cramps of the legs and arms, a possible concomitant of every kind of diarrhœa, is peculiarly severe and frequent in that caused by arsenic.

The general system always sympathizes acutely with the local derangement. The pulse commonly becomes very small, feeble and rapid soon after the vomiting sets in; and in no long time it is often imperceptible. This state is naturally attended with great coldness, clammy sweats, and lividity of the feet and hands. Another symptom referrible to the circulation which has been observed, though, very rarely, is palpitation.[^[621]]

The countenance is commonly collapsed from an early period, and almost always expressive of great torture and extreme anxiety or despair; the eyes are red and sparkling; the conjunctiva often so injected as to seem inflamed; the tongue and mouth parched; and the velum and palate sometimes covered with little white ulcers.

Delirium sometimes accompanies the advanced stage, and stupor also is not unfrequent. Coma occasionally precedes death, as in Mr. Stallard’s case (p. [235]), in which the symptoms of irritation, at first very violent, gradually gave place in two hours to complete insensibility, proving fatal in two hours more. Very often, however, the patient remains quite sensible to the last. Death in general comes on calmly, but is sometimes preceded by a paroxysm of convulsions.[^[622]] In some cases it takes place quite unexpectedly, as if from sudden deliquium, as in a case mentioned by Dr. Dymock of this city. The patient, a girl who had taken two ounces intentionally, rose from her bed without help two hours and a half afterwards, went to a chair at the fireside, and had scarce sat down when she expired.[^[623]]

Various eruptions have at times been observed, especially in those who survive several days; but they are more frequent in the kind of cases to be considered afterwards, in which life is prolonged for a week or more. The eruptions have been variously described as resembling petechiæ, or measles, or red miliaria, or small-pox. In the case already quoted from Guilbert a copious eruption of miliary vesicles appeared on the fifth day, and for fifteen days afterwards. They were attended with perspiration and abatement of the other symptoms, and followed with desquamation of the cuticle. Another external affection which may be noticed is general swelling of the body. Several cases of this nature have been described by Dr. Schlegel of Meiningen; and in one of them the swelling, particularly round the eyes, appears to have been considerable.[^[624]]

In some cases of the kind now under consideration a short remission or even a total intermission of all the distressing symptoms has been witnessed, particularly when death is retarded till the close of the second or third day.[^[625]] This remission, which is accompanied with dozing stupor, is most generally observed about the beginning of the second day. It is merely temporary, the symptoms speedily returning with equal or increased violence. Sometimes the remission occurs oftener than once, as in a case related in the London Medical and Physical Journal. The patient, a child seven years old, lived thirty-six hours in a state of alternate calm and excitement; and during the state of calm no pulse was to be felt at the wrists.[^[626]]—So far as at present appears a long intermission is impossible.

In cases such as those now described death often occurs about twenty-four hours after the poison is swallowed, and generally before the close of the third day. But on the one hand life has been sometimes prolonged, without the supervention of the symptoms belonging to a different variety of cases, for five or six days,[^[627]] nay perhaps even for several weeks. And, on the other hand, the symptoms of irritation of the alimentary canal are sometimes distinct, although death takes place in a much shorter period than twenty-four hours. Metzger has related a striking case, fatal in six hours, in which the symptoms were acute colic pain, violent vomiting, and profuse diarrhœa;[^[628]] and Wildberg has related a similar case fatal in the same time.[^[629]] Hohnbaum describes another fatal in five hours;[^[630]] and I met with as brief a case in this city in 1843, where all the usual symptoms of irritation in the stomach and bowels were violent. These symptoms were also present at first in Mr. Stallard’s case, which was fatal in four hours; Pyl has recorded one, where all the signs of irritation in the stomach and intestines were present, except vomiting, and which proved fatal in three hours;[^[631]] and Dr. Dymock met here with a similar instance which lasted only two hours and a half.[^[632]] This is one of the shortest undoubted cases of poisoning from arsenic I have hitherto found in authentic records. Dr. Male mentions one, which was fatal in four hours;[^[633]] Wepfer another equally short;[^[634]] Johnston another fatal in three hours and a half;[^[635]] and I shall presently mention others without symptoms of irritation which ended fatally in two, five, or six hours [p. [242]].[^[636]] Wibmer has even quoted a case fatal in half an hour; but there seems to have been some doubt whether the poison taken was arsenic.[^[637]]

Such is an account of the symptoms of poisoning by arsenic in their most frequent form. It will of course be understood, that they are liable to a great variety as to violence, as well as their mode of combination in actual cases;—and that they are by no means all present in every instance. The most remarkable and least variable of them all, pain and vomiting, are sometimes wanting. A case, in which pain was not felt in the stomach, even on pressure, although the other symptoms of inflammation were present, has been briefly described in the Medical Repository.[^[638]] A similar case fatal in fourteen hours and a half, where there was much vomiting and some heat in the stomach, but no pain or tenderness, has been related by Dr. E. Gairdner.[^[639]] Another very striking example of this anomalous deficiency has been detailed by Dr. Yellowly. A lad sixteen years old died twenty-one hours after swallowing half an ounce of the white oxide; and the presence of inflammation was denoted all along by sickness, vomiting, purging, and heat in the tongue; yet he never complained of pain, neither did he ever seem to his friends to suffer any. Another anomaly in the case was, that the pulse, contrary to what is usual, was very slow: twelve hours after he took the poison, the pulse was 40, and two hours before death it was so slow as 30.[^[640]] These deviations from the ordinary course of the symptoms are taken notice of merely to put the practitioner on his guard, and prevent the medical jurist from drawing hasty conclusions. Upon the whole, they are rare; and the symptoms of poisoning by arsenic are in general very uniform.

2. The second variety of poisoning with arsenic includes a few cases in which the signs of inflammation are far from violent or even altogether wanting, and in which death ensues in five or six hours or a little more,—at a period too early for inflammation to be always properly developed. The symptoms are then generally obscure, and are referrible chiefly to the mode of action, which is probably the cause of death in most cases,—a powerful debilitating influence on the circulation, or on the nervous system.

These symptoms occasionally amount to absolute narcotism, as in some of the animals on which Sir B. Brodie experimented. Thus, when he injected a solution of the oxide into the stomach of a dog, the pulse was rendered slow and intermitting; the animal became palsied in the hind-legs, lethargic, and in no long time insensible, with dilated pupils; and soon afterwards it was seized with convulsions, amidst which it died, fifty minutes after the poison was administered.[^[641]] In man the symptoms very seldom resembled so closely those of the narcotic poisons. In Mr. Stallard’s case, however, formerly mentioned, the symptoms of irritation which appeared at first speedily gave place to complete insensibility for two hours before death (pp. [235], 238), a similar instance has been related in Henke’s Journal. A young man who got an arsenical solution from an old woman to cure ague, was attacked after taking it with vomiting and loud cries, afterwards with incoherent talking, then fell into a deep sleep, and finally perished in convulsions in five hours.[^[642]]

In some cases of the kind now under consideration, one or two attacks of vomiting occur at the usual interval after the taking of the poison; but it seldom continues. The most uniform and remarkable affection is extreme faintness, amounting at times to deliquium. Occasionally there is some stupor, or rather oppression, and often slight convulsions. Pain in the stomach is generally present; but it is slight, and seldom accompanied with other signs of internal inflammation. Death commonly takes place in a few hours. Yet, even when it is retarded till the beginning of the second day, the faintness and stupor are sometimes more striking features in the case than the symptoms of inflammation in the stomach.

This variety of poisoning has been hitherto observed only under the three following circumstances,—when the dose of poison was large,—when it was in little masses,—or when it was in a state of solution. The mode in which the first and last circumstances operate is evident; they facilitate the absorption of a large quantity of arsenic in a short space of time, so that its remote action begins before local inflammation is fully developed. But it is not easy to see how any such effect can flow from the arsenic being in little masses. It is also to be observed that none of the circumstances here mentioned is invariable in its operation. An instance is related in Rust’s Magazine, of the customary signs of irritation having been produced even by the solution.[^[643]]

On the whole, the present variety of poisoning is rather uncommon, and indeed, although the attention of the profession was pointedly called to it even in the first edition of the present work, its existence does not seem to be so generally known as it ought to be.[^[644]] It may be right therefore to specify the cases which have been published.

In the Medical and Philosophical Journal of New York,[^[645]] is related the case of a druggist, who swallowed an ounce of powdered arsenic at once, and died in eight hours, after two or three fits of vomiting, with slight pain and heat in the stomach.—A similar case has been related by Metzger. A young woman died in a few hours, after suffering from trivial diarrhœa, pain in the stomach and strangury; her death was immediately preceded by slight convulsions and fits of suffocation; and on dissection the stomach and intestines were found quite healthy. Half an ounce of arsenic was found in the stomach.[^[646]]—A third case similar in its particulars to the two preceding was submitted to me for investigation by the sheriff of this county in 1825. The subject, a girl fourteen years of age, took about ninety grains, and died in five hours, having vomited once or twice, complained of some little pain in the belly, and been affected towards the close with great faintness and weakness. The stomach and intestines were healthy.[^[647]]—A fourth case allied to these is succinctly told in the Medical and Physical Journal. The person expired in five hours; and vomiting never occurred, even though emetics were given.[^[648]]—A fifth has been related by M. Gérard of Beauvais. The subject was a man so addicted to drinking, that his daily allowance was a pint of brandy. When first seen, there was so much tranquillity, that doubts were entertained whether arsenic had really been swallowed; but at length he was discovered actually chewing it. This state continued for nearly five hours, when some vomiting ensued: coldness of the extremities and spasmodic flexion of the legs soon followed; and in a few minutes more he expired.[^[649]]—A sixth and very singular case of the same kind has been described by Orfila. The individual having swallowed three drachms at eight in the morning, went about for two hours bidding adieu to his friends and telling what he had done. He was then prevailed on to take emetics and diluents, which caused free, easy vomiting. He suffered very little till one, when he became affected with constricting pain and burning in the stomach, feeble pulse, cold sweats, and cadaverous expression, under which symptoms he died four hours later.[^[650]] Orfila justly designates this case as the most extraordinary instance of poisoning with arsenic that has come under his notice.—A seventh is related by Mr. Holland of Manchester where death took place in the course of eight or nine hours, and the symptoms were at first some vomiting, afterwards little else but faintness, sickness, a sullen expression, and a general appearance which led those around to suppose the individual intoxicated.[^[651]]—Professor Chaussier has described a still more striking case than any yet mentioned. A stout middle-aged man swallowed a large quantity of arsenic in fragments and died in a few hours. He experienced nothing but great feebleness and frequent tendency to fainting. The stomach and intestines were not in the slightest degree affected during life; and no morbid appearance could be discovered in them after death,[^[652]]—A similar instance not less remarkable has been communicated to me by Mr. Macauley of Leicester, where the individual died with narcotic symptoms only within two hours after taking nearly a quarter of a pound of arsenic.—Another fatal in four hours has been described by Mr. Wright, where the symptoms were vomiting under the use of emetics, great exhaustion, feeble hurried pulse, cold sweating, drowsiness and finally stupor. In this case the quantity of arsenic taken was about an ounce.[^[653]]—Another of the same nature is recorded by Morgagni. An old woman stole and ate a cake, which had been poisoned with arsenic for rats. She died in twelve hours, suffering, says Morgagni, rather from excessive prostration of strength than from pain or convulsions.[^[654]]—The following case related by M. Laborde is most remarkable in its circumstances. A young woman was caught in the act of swallowing little fragments of arsenic, and it afterwards appeared that she had been employed most of the day in literally cracking and chewing lumps of it. When the physician first saw her the countenance expressed chagrin and melancholy, but not suffering. After being forced to drink she vomited a good deal, but without uneasiness. Two hours afterwards her countenance was anxious; but she did not make any complaint, and very soon resumed her tranquillity. Five hours after the last portions of the poison were taken she became drowsy, then remained perfectly calm for four hours more, and at length on trying to sit up in bed, complained of slight pain in the stomach, and expired without agony. A clot of blood was found in the stomach.[^[655]]—Dr. Platner of Pavia describes a case, fatal probably in five hours, where the symptoms were a tranquil, melancholic expression, great coldness, paleness of the features, slow languid pulse, retarded respiration, and suppression of urine, but no pain or swelling of the belly, and no diarrhœa till near death, when there was one copious fluid evacuation.[^[656]]—Lastly, Dr. Choulant has related the case of an elderly female who got a thimbleful of arsenic in soup, and died in eleven hours, affected with occasional, easy vomiting, uneasiness, thirst, and undefinable uneasiness in the chest, but without pain of any kind, or any other complaint.[^[657]]

The cases of which an abstract has here been given, will, it is apprehended, be sufficient to correct the erroneous impression of many,—that arsenic, when it proves fatal, always produces violent and well-marked symptoms. It will of course be understood that cases of the present kind pass by insensible shades into those of the first class,—the following, for example, being intermediate between the two. A young man had frequent vomiting and diarrhœa, which were supposed to depend on indigestion merely, as the countenance was calm, without any appearance of suffering, the appetite tolerable, and the abdomen quite free of tenderness. The pulse, however, quickly sunk, the voice failed, and death took place in eleven hours; and on dissection about twenty grains of arsenic were found in the stomach with strong signs of inflammation.[^[658]]—In a case communicated to me by a former pupil, Mr. Adams of Glasgow, that of a woman who died five hours after taking six drachms of arsenic, there was some vomiting not long after she swallowed it; but subsequently she presented no prominent symptoms except a ghastly expression, redness of the eyes, a fluttering pulse and extreme prostration, until within half an hour before death, when the action of an emetic and the stomach-pump was followed by severe burning pain.

3. The third variety of poisoning with arsenic places in a clear point of view its occasional action on the nervous system. This occurs chiefly in persons who, from having taken but a small quantity, or from having vomited soon after, are eventually rescued from destruction; but it has also been met with in some cases where death ensued after a protracted illness.

In such cases the progress of the poisoning may be divided into two stages. The first train of symptoms is exactly that of the first or inflammatory variety, and is commonly developed in a very perfect and violent form. In the second stage the symptoms are referrible to nervous irritation.

These generally come on when the former begin to recede; yet sometimes they make their appearance earlier, while the signs of inflammation in the alimentary canal continue violent; and more rarely both classes of symptoms begin about the same period. The nervous affection varies in different individuals. The most formidable is coma; the slightest, a peculiar, imperfect palsy of the arms or legs, resembling what is occasioned by the poison of lead; and between these extremes have been observed epileptic fits, or tetanus, or an affection resembling hysteria, or mania. As these affections are of much interest, in respect to the evidence of poisoning from symptoms, it may be well to relate in abstract a few characteristic examples of each.

A good example of epilepsy supervening on the ordinary symptoms of inflammation has been minutely related by Dr. Roget. A girl swallowed a drachm of arsenic, and was in consequence attacked violently with the usual symptoms of irritation in the whole alimentary canal. After being ill about twenty-four hours, she experienced several distinct remissions and had some repose, attended with fainting. In twelve hours more she began to improve rapidly; the pain subsided, her strength and spirits returned, and the stomach became capable of retaining liquids. So far this patient laboured under the common effects of arsenic. But a new train of symptoms then gradually approached. Towards the close of the second day she was harassed with frightful dreams, starting from sleep, and tendency to faint; next morning with coldness along the spine, giddiness, and intolerance of light; and on the fourth day with aching of the extremities and tingling of the whole skin. These symptoms continued till the close of the sixth day, when she was suddenly seized with convulsions of the left side, foaming at the mouth, and total insensibility. The convulsions endured two hours, the insensibility throughout the whole night. Next evening she had another and a similar fit. A third, but slighter fit occurred on the morning of the tenth; another next day at noon; and they continued to return occasionally till the nineteenth day. For some time longer she was affected with tightness across the chest and stomach complaints; but she was eventually restored to perfect health.[^[659]]

A characteristic set of similar cases, which occurred in London in 1815, has been related in a treatise on arsenic by Mr. Marshall.[^[660]] They were the subject of investigation on the trial of Eliza Fenning, a maid-servant, who attempted to poison the whole of her master’s family by mixing arsenic with a dumpling, and whose condemnation excited an extraordinary sensation at the time, as many persons believed her to be innocent. Five individuals partook of the poisoned dish, and they were all violently seized with the usual inflammatory symptoms. But farther, one had an epileptic fit on the first day, which returned on the second, and he had besides frequent twitches of the muscles of the trunk, a feeling of numbness in one side, and heat and tingling of the feet and hands. Another had tremors of the right arm and leg on the first day, and several epileptic fits in the course of the night. During the next fifteen days he had a paroxysm every evening about the same hour; which returned after an intermission of eight days, and frequently for several months afterwards.

In the following set of cases the nervous symptoms exhibited a singular combination of delirium, convulsions, tetanus, and coma, such as is frequently met with in paroxysms of hysteria; but the cases are probably not pure examples of poisoning with arsenic, for liver of sulphur was administered as a remedy to a considerable amount. Three servant girls in one of the Hebrides ate a mixture of lard, sugar, and arsenic, which had been laid for destroying rats. The ordinary signs of irritation in the stomach ensued, but on the following morning were greatly mitigated. They were then ordered twelve grains of liver of sulphur every other hour. Soon afterwards the inflammatory symptoms became more severe, the root of the tongue swelled and inflamed, and in the afternoon two of them lost the power of speech and swallowing, and were attacked with locked-jaw and general convulsions. The third had not locked-jaw, but was otherwise similarly, affected. On the morning of the third day one of the two former was found comatose, with continuance of the locked-jaw and occasional return of convulsions; and on being roused by venesection and the cold affusion, she complained of headache and heat in the throat. The sulphuret of potass, which had been discontinued on account of the locked-jaw, was then resumed. On the evening of the fourth day the headache increased, and the patient became delirious and unmanageable. The cold affusion, however, soon restored her again to her senses, and from that time her recovery was progressive. In the other patients the symptoms were similar, but less violent. In these instances the evidence of an injury of the nervous system was decisive; but it may be doubted whether the symptoms were not, in part at least, owing to the sulphuret of potass, which has been already described as an active poison, capable of inducing convulsions and tetanus. Its properties were not generally known in this country at the time the cases in question happened.[^[661]]

Sometimes the convulsions caused by arsenic assume the form of pure tetanus. At least a case of this affection is noticed by Portal.[^[662]] He has given only a mere announcement of it; and I have not hitherto met with a parallel instance in authors.

A common nervous affection in the advanced stage of the more tedious cases of poisoning with arsenic is partial palsy. Palsy in the form of incomplete paraplegia is a very common symptom even of the early stage in animals, and has been also sometimes observed during that stage in man. The paralytic affection, however, is more frequent in the advanced stage; and in those persons who recover, an incomplete paralysis of one or more of the extremities, resembling lead palsy, is often the last symptom which continues.

Dehaen relates a distinct example of this disorder occurring in a female who took a small quantity of arsenic by mistake. The ordinary signs of inflammation were soon subdued, and for three days she did well; but on the fourth she was attacked with cramps, tenderness, and weakness of the feet, legs and arms, increasing gradually till the whole extremities became at length almost completely palsied. At the same time the cuticle desquamated. But the other functions continued entire. The power of motion returned first in the hands, then in the arms, and she eventually recovered; but eleven months passed before she could quit the hospital where Dehaen treated her.[^[663]]

An excellent account of a set of similar cases has been given by Dr. Murray of Aberdeen. They became the subject of judicial inquiry on the trial of George Thom, who was condemned in 1821 at the Aberdeen autumn circuit for poisoning his brother-in-law. Four persons were simultaneously affected about an hour after breakfast with the primary symptoms of poisoning with arsenic, and some in a very violent degree. But besides these symptoms, in all of them the muscular debility was great; and in two it amounted to true partial palsy. One of them lost altogether the power of the left arm, and six months after, when the account of the cases was published, he was unable to bend the arm at the elbow-joint. The other had also great general debility and long-continued numbness and pains of the legs.[^[664]]

An interesting case of the same nature with these was lately submitted to me on the part of the crown. A man after taking arsenic was attacked with vomiting, purging, and other symptoms of abdominal irritation, which were mistaken for dysentery. Five days afterwards he began to suffer also from feebleness of the limbs; amounting almost to palsy. Subsequently an improvement slowly took place; but he continued to suffer under irritative fever, diarrhœa, and faintness. Several weeks later the diarrhœa abated, but he had great stiffness, numbness, and loss of power in the joints of the hands and feet. Two months after he first took ill, and while he was slowly recovering from this paralytic affection, arsenic was again administered and proved fatal in eighteen hours.

Another, somewhat similar to the preceding, has been related by M. Lachèse of Angers. Two people took about half a grain in soup twice a day for two days, and were attacked with the usual primary symptoms. One of them died in ten weeks, gradually worn out, but without any particular nervous affection. The other was seized with convulsions, and afterwards with almost complete palsy of the limbs.[^[665]]—A well-marked case of the same nature has been noticed by Professor Bernt. It was the case formerly alluded to as arising from an over-dose of the arseniate of potass. The paralytic affection consisted in the loss of sensation and of the power of motion in the hands, and of the loss of motion in the feet, with contraction of the knee-joints. The issue of the case is not mentioned.[^[666]]—Dr. Falconer observes in his essay on Palsy, that he had repeatedly witnessed local palsy after poisoning with arsenic, and alludes to one instance in which the hands only were paralysed, and to two others in which the palsy spread gradually from the fingers upwards till the whole arms were affected.[^[667]]—On the whole, then, local palsy is the most frequent of the secondary effects of arsenic.

It is sometimes very obstinate, as the cases related by Dehaen and Murray will show. But it even appears to be sometimes incurable. For in the German Ephemerides there is related the case of a cook, who after suffering from the usual inflammatory symptoms, was attacked with perfect palsy of the limbs, and had not any use of them during the rest of her life, which was not a short one.[^[668]]

Occasionally, instead of being palsied, the limbs are rigidly bent and cannot be extended.[^[669]] They were contracted, as well as palsied in the case noticed by Bernt.

The last nervous affection to be mentioned is mania. The only instance I have hitherto found of that disease arising from arsenic is related by Amatus Lusitanus. He has not recorded the particulars of the case, but merely observes that the individual became so outrageously mad as to burst his fetters and jump out of the window of his apartment.[^[670]] According to Zacchias, Amatus was not very scrupulous in his adherence to fact in recording cases.

The preceding remarks contain all that is known with certainty of the effect of arsenic on man when it is swallowed. Independently of the obvious nervous disorders which succeed the acute symptoms, other morbid affections of a more obscure character and chronic in their nature have been sometimes observed or supposed to arise from this poison.—Among these the most unequivocal is dyspepsia. Irritability of the stomach, attended with constant vomiting of food, has been occasionally noticed for a long time after. Wepfer has described two cases in which the primary symptoms were followed, in one by dyspepsia of three years’ standing, in the other by emaciation and an anomalous fever, which ended fatally in three years.[^[671]]—Hahnemann farther adds, that in the advanced stage the hair sometimes drops out, and the cuticle desquamates, accompanied occasionally with great tenderness of the skin;[^[672]] and Wibmer mentions a case of the kind, where not the cuticle and hair only, but likewise even the nails, fell off.[^[673]] Desquamation of the cuticle and dropping of the nails are at times produced by the continued use of arsenic in medicinal doses.—Other effects have likewise been ascribed to its employment medicinally. Thus passing over what was stated by its opponents at the time when its introduction into the materia medica was made the subject of controversy over Europe, Broussais maintained that it causes chronic inflammation of the stomach or intestines;[^[674]] and Dr. Astbury inferred, from an instance which fell under his notice, that it may bring on dropsy.[^[675]] Neither of these ideas is supported by the general experience of the profession; and although some persons even of late have alleged that those, who take it medicinally to any material amount, invariably die soon after of some chronic disease,[^[676]] there cannot be a doubt, that, under proper restriction, it is both an effectual and a safe remedy.—A case where salivation, with fetor and superficial ulceration of the gums, seemed to have been produced by arsenic, was lately published in an English Journal.[^[677]]

In the present place may also be considered the supposed effects of the celebrated Aqua Toffana or Acquetta di Napoli, a slow poison, which in the sixteenth century, was believed to possess the property of causing death at any determinate period, after months for example, or even years, of ill health, according to the will of the poisoner.

The most authentic description of the aqua Toffana ascribes its properties to arsenic. According to a letter addressed to Hoffman by Garelli, physician to Charles the Sixth of Austria, that Emperor told Garelli, that, being governor of Naples at the time the aqua Toffana was the dread of every noble family in the city, and when the subject was investigated legally, he had an opportunity of examining all the documents,—and that he found the poison was a solution of arsenic in aqua cymbalariæ.[^[678]] The dose was said to be from four to six drops. It was colourless, transparent, and tasteless, like water.

Its alleged effects are thus eloquently described by Behrends, a writer in Uden and Pyl’s Magazin. “A certain indescribable change is felt in the whole body, which leads the person to complain to his physician. The physician examines and reflects, but finds no symptom, either external or internal,—no constipation, no vomiting, no inflammation, no fever. In short, he can advise only patience, strict regimen, and laxatives. The malady, however, creeps on; and the physician is again sent for. Still he cannot detect any symptom of note. He infers that there is some stagnation or corruption of the humours, and again advises laxatives. Meanwhile the poison takes firmer hold of the system; languor, wearisomeness and loathing of food continue; the nobler organs gradually become torpid, and the lungs in particular at length begin to suffer. In a word, the malady is from the first incurable; the unhappy victim pines away insensibly, even in the hands of his physician; and thus is he brought to a miserable end through months or years, according to his enemy’s desire.”[^[679]] An equally vigorous and somewhat clearer account of the symptoms is given by Hahnemann. “They are,” says he, “a gradual sinking of the powers of life, without any violent symptom,—a nameless feeling of illness, failure of the strength, slight feverishness, want of sleep, lividity of the countenance, and an aversion to food and drink and all the other enjoyments of life. Dropsy closes the scene, along with black miliary eruptions, and convulsions, or colliquative perspiration and purging.”[^[680]]

Whatever were its real effects, there appears no doubt it was long used secretly in Italy to a fearful extent, the monster who has given her name to it having confessed that she was instrumental in the death of no less than six hundred persons. It has been already stated, however [p. [40]], that she owed her success rather to the ignorance of the age than to her own dexterity. At all events, the art of secret poisoning cannot now be easily practised. Indeed even the vulgar dread of it is almost extinct. Partly on account of the improvement in general knowledge and chiefly in consequence of the subtility and precision, which the refinement of modern physic and chemistry have introduced into medico-legal inquiries, it is rare that the suspicious scrutiny of the world now “recognizes in the accounts of the last illness of popes and princes the effects of poison insidiously introduced into the body.”[^[681]]

I may add in conclusion, that I was consulted a few years ago on the part of the crown in a case which considerably resembled the effects ascribed in former times to the aqua Toffana, except that it was more acute in its character and swifter in its progress. As this case will probably be found to represent pretty nearly the usual effects of moderate doses frequently repeated, it is here given in some detail.

A woman of indifferent character married a young man in circumstances which led to a breach between him and his relatives; but the pair appeared to live on good terms with one another. Eighteen months after the marriage she was attacked with sickness and faintness; and on the fourth day of this illness, while she was recovering, the symptoms unexpectedly increased, and she seemed very unwell. On the fifth day she became extremely weak, and suffered much from yellow vomiting. On the seventh, when she was first visited by a medical man, she had frequent vomiting, burning in the stomach, a yellow tongue, flushed countenance, hot skin, and hurried pulse. On the ninth the throat was sore and red, and the expression anxious; and next day the soreness was greater, affected the nose and mouth also, and was attended with excoriation of the lips and nostrils, swelling of the glands of the throat, dimness of sight, and great exhaustion. On the eleventh day, while previously again getting better, she became much worse, and suffered greatly from excessive vomiting, pain in the stomach, and an increase of the other symptoms. On the thirteenth she was very hoarse, and despaired of recovery. Next day she was occasionally incoherent, and had twitches of the facial muscles; the hands and face were swelled, the eyelids dingy, the conjunctivæ injected, and the nails blue. On the morning of the fifteenth there was for two hours violent delirium and fierce maniacal excitement, which were succeeded by coma, and this by death in the course of the evening. There was no diarrhœa, or urinary complaint, and no paralysis or eruption on the skin. A variety of circumstances of a general nature, which it would be out of place to enumerate here,—the detection of arsenic in various articles of which the woman had partaken, and in which the arsenic had been dissolved sometimes simply, sometimes with the aid of an alkali,—together with the fact, that the body five months after death was found preserved from decay, as it is now well known to be in most cases of arsenical poisoning,—left little doubt that the woman died of the effects of arsenic taken in several small doses at distant intervals, although none could be detected in the stomach or intestines. The case did not go to trial, owing to the death of an essential witness.

The effects of arsenic on man, when introduced into the living body through other channels besides the stomach, will now require some observations. It is necessary for the medical jurist to be well acquainted with them, because there is hardly an accessible part of the human body to which this poison has not been applied either accidentally or by design. When some account was given of its comparative action on the different tissues of animals, it was observed that arsenic acts when applied to a wound or ulcer, to the peritonæal membrane, to the eye, and to the vagina. On man it has been known to act through an ulcer or wound, the inner membrane of the rectum, the membrane of the vagina, the membrane of the air-tubes, the membrane of the nose, and even the sound skin.

Many persons have been poisoned by the application of arsenic to surfaces deprived of the cuticle, such as blistered surfaces, eruptions, ulcers, or wounds. When applied in this manner it commonly induces both local inflammation and constitutional symptoms. Amatus Lusitanus relates the case of a young man, who, against the advice of his physician, anointed an itchy eruption of the skin with an arsenical ointment, and next day was found dead in bed.[^[682]] A similar case, not so rapidly fatal, has been recorded by Wepfer. A girl, affected with psoriasis of the scalp, had it rubbed with a liniment of butter and arsenic. In a short time she was seized with acute pain and swelling of the whole head, fainting-fits, restlessness, fever, delirium, and she died in six days.[^[683]] Zitmann has noticed the cases of two children, eight and ten years of age, who were killed by the application of an arsenical solution to a similar eruption of the head.[^[684]] And Belloc relates the case of a woman who, trying to cure an inveterate itch with an arsenical lotion, was attacked in consequence with severe erysipelas of the whole body, succeeded by tremors and gradual exhaustion of the vital powers, ending fatally in two years.[^[685]] M. Errard of Injurieux in France lately met with two cases, where, in consequence of a freshly blistered surface being dressed with a cerate made with the stearine of arsenicated candles (see p. [256]), local pain, nausea, pain in the stomach, urgent thirst, redness of the tongue, involuntary contractions of the muscles of the extremities, and weakness and irregularity of the pulse came on; and one person died within twenty-four hours, while the other recovered, chiefly because the dressing caused so much pain that the patient could not keep it on long.[^[686]]

Next as to ulcers; M. Roux has noticed the case of a girl, who was killed by the application of the arsenical paste to an ulcer of the breast, and in whom the constitutional symptoms were strongly marked, although the quantity of the poison must have been very small. The preparation used, which contains only a twenty-fourth of its weight of arsenic, was applied for a single night on a surface not exceeding an inch and a half in diameter. Yet she complained next day of violent colic and vomited frequently, the countenance soon became collapsed, and she died two days afterwards in great anguish.[^[687]] Another instance of the like kind is related in the Annales d’Hygiène, where death arose from an arsenical ointment ignorantly applied for scirrhous breast over a large surface of the skin stripped of the cuticle by a blister. The particular symptoms and their duration are not stated; but there was violent irritation of the stomach.[^[688]] Another fatal case, related by Dr. Küchler, arose from the application of Frêre Cosme’s powder to a soft fungoid tumour on the temple, which discharged serum usually and blood upon slight pressure. About a drachm and a half of arsenic mixed with fifteen grains of other powders was applied. Severe inflammation spread round the tumour next day; and soon afterwards, the patient was attacked with great difficulty of breathing, thirst, pains in the belly, and purging, then with difficulty in swallowing from swelling of the base of the tongue, delirium, cold sweating, and extreme debility; and death ensued in four days.[^[689]]

There is a singular uncertainty in the effects of arsenic when applied to ulcerated surfaces. Some persons, like Roux’s patient, are obviously affected by a single application; while others have had it applied for a long time without experiencing any other consequences than the formation of an eschar at the part. Two causes have been assigned for these differences, and probably both are founded on fact. One, which has been assigned by Mr. Blackadder, is the relative quantity of arsenic applied. He says he never witnessed but one instance of its acting constitutionally, although he often applied it to sores; and he imputes this success to his having always used a large quantity. For he considers that by so doing the organization of the part is quickly destroyed, and absorption prevented,—but that if the quantity be small, as in the mode practised by Roux, it will cause little local injury and readily enter the absorbing vessels.[^[690]] Another unequivocal cause is pointed out by Harles in his treatise on arsenic. While treating of its therapeutic properties, and noticing the controversy that prevailed last century throughout Europe respecting the propriety of its outward application, he remarks that it may be applied with safety to the abraded skin, to common ulcers, to wounded surfaces, and to malignant glandular ulcers, even when highly irritable, provided the part be not recently wounded, so as to pour out blood.[^[691]] The reason of this is obvious; the application of the poison to open-mouthed vessels is the next thing to its direct introduction into a vein. It is some confirmation of Harles’s opinion, that Roux, whose patient was so easily affected, recommends that before arsenic is applied to an ulcer, a fresh surface be made by paring away the granulations; and that Küchler’s patient had an ulcer which did not discharge pus, but serum, and was easily made to bleed.

In the cases related above it will be remarked that the symptoms vary in their nature. Sometimes the chief disorder is inflammation, spreading over and around the eruption or ulcer, sometimes inflammation of the alimentary canal, sometimes an affection of the nervous system. In general the sufferings of the patient both from the local inflammation and constitutional symptoms are very severe. But this rule has its exceptions. In Pyl’s Memoirs there is the history of a child who died four days after an itchy eruption of the whole body had been washed with an arsenical solution, and signs of vivid inflammation were found after death in many parts; yet she appears to have complained only of headache.[^[692]] Occasionally too, without exciting either inflammation of the part, or disorder of the stomach, or a general injury of the nervous system, it seems to give rise to partial palsy of the muscles adjoining the seat of its application. An extraordinary case is noticed in an American Journal, in which the prolonged use of an arsenical preparation for destroying a tumour on the right side of the neck, was followed by complete palsy of the muscles of the neck and arm of that side.

In the next place, poisoning has been perpetrated by introducing arsenic into the fundament with an injection.[^[693]] Foderé has noticed a case of this kind, which happened in France, and was communicated to him by a physician of Thoulouse. A lady under medical treatment for some trifling illness, died unexpectedly under symptoms of poisoning; and it was discovered that her servant, after unsuccessfully attempting to despatch her by dissolving arsenic in her soup, had ultimately succeeded by administering it repeatedly in injections.[^[694]] There is no doubt that by this mode all the usual effects of arsenic may be induced; and on account of the facility with which the colon and rectum may be evacuated, it is not likely that the poison will be found in the gut after death, if the individual did not die in a few hours after its administration.

In the third place, women have also died of poisoning by arsenic introduced into the vagina. Two examples of this revolting crime are on record. One of them occurred in 1799, in the Department of the Ourthe in France. A middle-aged female was seized with vomiting, diarrhœa, swelling of the genitals and uterine discharge; and she expired not long after. Before her death she told two of her neighbours, that her husband had some time before tried to poison her by putting arsenic in her coffee, and had at length succeeded by introducing a powder into her vagina while in the act of enjoying his nuptial rights. The vulva and vagina were gangrenous, the belly distended with gases, and the intestines inflamed.[^[695]]

The other case, which happened in Finland in 1786, gave rise to an excellent dissertation on the subject by Dr. Mangor, at that time medical inspector for Copenhagen. A farmer near Copenhagen lost his wife suddenly under suspicious circumstances, and six weeks afterwards married his maid-servant. In a few years he transferred his affections to another maid-servant, with whose aid he endeavoured to poison his second wife. For some time his attempts proved abortive; till at last one morning, after coïtion, he introduced a mixture of arsenic and flour on the point of his finger into the vagina. She took ill at mid-day and expired next morning; and the murderer soon after married his guilty paramour. But a few years had not elapsed before he got tired of her also; and one morning, after the conjugal embrace, he administered arsenic to her in the same way as to her predecessor. About three in the afternoon, while enjoying good health, she was suddenly seized with shivering and heat in the vagina. The remembrance of her former wickedness soon awoke the suspicions of the unhappy woman, and she wrung from her husband a confession of his crime. Means were resorted to for saving her life, but in vain: She was attacked with acute pain in her stomach and incessant vomiting, then became delirious, and died in twenty-one hours. After death grains of arsenic were found in the vagina, although frequent lotions had been used in the treatment. The labia were swollen and red, the vagina gaping and flaccid, the os uteri gangrenous, the duodenum inflamed, the stomach natural. In the course of the judicial proceedings which arose out of these two cases, Dr. Mangor made experiments on mares, with the view of settling the doubts which were entertained as to the likelihood of arsenic proving fatal in the manner alleged; and the results clearly showed that, when applied to the vagina of these animals, it produces violent local inflammation and fatal constitutional derangement.[^[696]]

In the fourth place, poisoning by arsenic through the bronchial membrane or membrane of the air-passages is a comparatively rare accident, which can take place only in consequence of arsenical gases or vapours being incautiously breathed. The effects of oxide of arsenic when introduced in this way are described from personal experience by Otto Tachenius, a chemist of the sixteenth century.

“Once,” said he, “when I happened to breathe incautiously the fumes of arsenic, I was surprised to find my palate impressed with a sweet, mild, grateful taste, such as I never experienced before. But in half an hour I was attacked with pain and tightness in the stomach, then with general convulsions, difficult breathing, an unspeakable sense of heat, bloody and painful micturition, and finally with such an acute colic as contracted my whole body for half an hour.” By the use of oleaginous drinks he recovered from these alarming symptoms; but during all the succeeding winter he had a low hectic fever.[^[697]]

Balthazar Timæus relates a similar case which came under his notice. An apothecary of Colberg, while subliming arsenic, had not been careful enough to avoid the fumes; and was soon after seized with frequent fainting, tightness in the præcordia, difficult breathing, inextinguishable thirst, parched throat, great restlessness, watching, and pains in the feet. He had afterwards profuse daily perspiration and palsy of the legs; and several months elapsed before he got entirely well.[^[698]] The same author says that the famous Paracelsus, being one day put out of temper by an acquaintance, made him hold his nose over an alembic in which arsenic was subliming; and that the object of this severe joke nearly lost his life in consequence. Wibmer quotes the heads of several cases where swelling of the tongue, headache and giddiness, nausea, and an oppressive sense of constriction in the throat, were occasioned by the incautious inhalation of arsenical fumes.[^[699]] The following extraordinary case, closely allied to malignant cholera in its early stage, has been ascribed by the reporter Dr. Welper of Berlin to the inspiration of arsenical fumes,—with what probability I am not prepared to say. A stout healthy man, who in the forenoon had freely and for some time exposed himself to the steam from a vessel where he was boiling several ounces of orpiment in water, was attacked at night with sickness, and next morning with extreme weakness and some difficulty of breathing. These symptoms were greatly relieved by an emetic. But towards evening the extremities became ice-cold and very stiff, the breathing much oppressed, the pulse very hurried, and imperceptible except in the neck, the mouth and throat dry, and the tongue rigid; but the mind remained clear, though anxious and afraid of impending dissolution. His state of collapse was removed in twelve hours by fomentations, and in no long time he recovered entirely except from the dyspnœa, which continued more or less till a few years afterwards, when he died of hydrothorax.[^[700]]

The slighter effects of arsenic are said to have been repeatedly observed of late in this country from inhaling the products of the combustion of arsenicated candles,—an article of recent invention, in which arsenic, to the extent of three or four grains and a half in each candle, is introduced for the purpose of hardening the stearine chiefly used in manufacturing them. It is unnecessary to say, that such candles are prejudicial and ought to be prohibited. In a set of experiments made to try their effects by Messrs. Everitt, Bird, and Phillips in 1838, birds were killed in no long time, and small quadrupeds were severely affected, when kept in an apartment lighted with them.[^[701]]

Analogous to the effects of inhaling oxide of arsenic are those lately observed from the incautious inhalation of arseniuretted-hydrogen gas. Gehlen the chemist died of this accident, but no particular account has been published of the symptoms he suffered. Two cases, however, have been detailed within a few years. In one of these, which has been related by Dr. Schlinder, of Greifenberg, the individual inhaled in forty minutes about half a cubic inch of the gas, which is equivalent to about an eighth of a grain of arsenic. In three hours he became affected with giddiness, and soon afterwards with an uneasy sense of pressure in the region of the kidney, passing gradually into acute pain there and upwards along the back. General shivering ensued, with coldness of the extremities, and gouty-like pains in the knees, shoulders, and elbows. The hands and lower half of the fore-arms, the feet and legs nearly to the knees, the nose and region of the eyebrows, felt as if quite dead, but without any diminution of muscular power. There was also acute pain in the stomach and belly generally, painful eructation of gas, and occasional vomiting of bitter, greenish-yellow mucus. The most tormenting symptom, however, was the pain in the kidneys, which soon became attended with constant desire to pass water, and the discharge of deep reddish-brown urine, mixed with clots of blood. The whole expression of the countenance was altered, the skin becoming dark brown, and the eyeballs sunk, yellow, and surrounded by a broad livid ring. Warm drink brought out a copious sweat and removed the sense of numbness; but next day there was little change otherwise in the symptoms, except that the urine was no longer mixed with clots, and that the hair on the benumbed parts had become white. On the third day the pains had abated, and the urine became clear; but there was hiccup, an excited state of the mind, and a feeling as if a great stone lay in the lower belly. In seven days he was much better. In the third week the whole glans and prepuce became covered with little pustules which were followed by small ulcers. It was not till the close of the seventh week that he recovered completely.[^[702]] Dr. O’Reilly has related the following case, which arose from the inhalation of hydrogen gas impregnated with arseniuretted-hydrogen in consequence of the sulphuric acid used for dissolving zinc having contained arsenic. Mr. Brittan, a Dublin chemist, wishing to ascertain the effects of hydrogen on the body, proceeded to inhale 150 cubic inches of it. Immediately after the second inhalation, he was seized with confusion, faintness, giddiness and shivering, and passed a stool, as well as two ounces of bloody urine, but without any pain. Pain in the limbs followed, and in two hours frequent vomiting and dull pain in the stomach. The pulse at this time was 90, the skin cold, and the voice feeble. Ammonia, laudanum, and emollient clysters gave him little relief. During the subsequent night there was frequent vomiting and no urine; the face became copper-coloured, and the rest of the body greenish; there was tenderness of the epigastrium and hiccup; but he was free of fever. On the third day there was diarrhœa and still no urine; but the jaundice had disappeared. On the fourth the breath was ammoniacal, and somnolency had set in. On the fifth the skin became again deeply jaundiced, and the face was œdematous; no urine had yet been discharged, and the bladder, examined with the catheter, was found empty. On the evening of the seventh day he expired. On examination of the body, two pints of red serum were found in the pleural cavities; the lungs were sound, the heart pale and flaccid, the liver indigo-blue, the gall-bladder distended with bile, the kidneys also indigo-blue, the stomach empty, and its villous coat brittle, with here and there inflamed-like spots on it, the bladder empty, the brain bloodless, the cellular tissue generally anasarcous. Arsenic was detected in the pleural serum. By an approximate calculation it was supposed that the hydrogen this gentleman inhaled had contained the equivalent arsenic of twelve grains of the oxide.[^[703]]

It would appear that arsenic acts with great rapidity and force when respired in any form.

Poisoning through the lining membrane of the nostrils is a still rarer accident than that last mentioned. There is a distinct example of it in the German Ephemerides, which arose from an arsenical solution having been used by mistake as a lotion for a chronic discharge from the nostrils. The individual was attacked with a profuse discharge from the nostrils, and then with stupor approaching to coma. Weakness of sight and of memory continued after sensibility returned; and he died two years afterwards, death having been preceded for some time by convulsions.[^[704]]

Arsenic when applied to the sound skin of animals does not easily affect them. The experiments of Jaeger formerly noticed prove that no effect is produced, if the poison is simply placed in contact with the skin. Nay even when rubbed into it with fatty matters it does not operate with energy; for in that case, according to the experiments of Renault, it causes sometimes a pustular eruption, sometimes an eschar, but never any constitutional disorder.[^[705]] It is more energetic, however, when applied to the more delicate skin of the human subject. Some experiments were made by Mr. Sherwen on himself with the view of proving this;[^[706]] but they are not satisfactory. The following facts, however, will show that it may produce through the sound skin all the ordinary signs of poisoning. Desgranges, a good authority, relates the case of a woman who anointed her head with an arsenical ointment to kill lice, and, after using it several days, was attacked with erysipelas of the head and face, attended with ulceration of the scalp, swelling of the salivary and cervical glands, and inflammation of the eyes. There were likewise violent constitutional symptoms,—much fever, fainting, giddiness, vomiting and pain in the stomach, tenesmus, and ardor urinæ, tremors of the limbs, and even occasional delirium. Afterwards the whole body became covered with an eruption of white papulæ, which dried and dropt off in forty-eight hours. She recovered gradually; but appears to have made a narrow escape. Her hair fell out during convalescence.[^[707]] A similar instance is recorded in the Acta Germanica for 1730. A schoolboy having found in the street a parcel of arsenic, his mother mistook it for hair powder; and as he had to deliver a valedictory speech at school next day, she advised him to powder himself well with it in the morning. This he accordingly did. In the middle of his speech he was attacked with acute pain of the face; and a fertile crop of pustules soon broke out upon it. The head afterwards swelled much, and the pustules spread all around it; he was tormented with intolerable heat in the scalp; and the hair became matted with the discharge into a thick scabby crust. This crust separated in a few weeks, and he soon recovered completely.[^[708]] Schulze, a German physician, has related no fewer than five cases of the same description, all arising from arsenic having been mistaken for hair powder; and one of them proved fatal. Two of the cases were slight. The other persons had the same violent inflammation of the head as Desgranges’s patient and the German schoolboy. In the fatal case death took place in twenty-one days; and on dissection, besides other morbid appearances, the scalp was found gangrenous and infiltered with fluid blood, and the stomach much inflamed.[^[709]] The two survivors, who were severely ill, it is well to add, were not attacked with the erysipelas of the scalp till six days after they powdered themselves. Sproegel mentions a fatal case from fly-powder having been applied in like manner to the head; and Wibmer quotes another, but not fatal, where from the same cause great swelling of the head and face arose, followed by erysipelas of the face, neck, and belly, and a papular eruption on the hands which continued five days.[^[710]]

From the statements now made, it is evident that arsenic applied to various parts of the external surface and natural apertures of the body, will prove poisonous, and will often act with a certainty and rapidity not surpassed by its effects when taken internally. Many of the cases furnish a striking confirmation of a circumstance formerly noticed with respect to its action,—namely, that it produces signs of irritation in the stomach, in whatever manner it is introduced into the body. In some instances, indeed, the signs of inflammation in the stomach were quite as distinct as in the cases previously described, where the poison was taken internally.

The subject of the symptoms caused by arsenic will now be concluded with a few remarks on the strength of the evidence which they supply.

The present doctrine of toxicologists and medical jurists seems generally to be, that symptoms alone can never supply decisive proof of the administration of arsenic. This opinion is certainly quite correct when applied to what may be called a common case of poisoning with arsenic, the symptoms of which are little else than burning pain in the stomach and bowels, vomiting and purging, feeble circulation, excessive debility, and speedy death. All these symptoms may be caused by natural disease, more particularly by cholera; and consequently every sound medical jurist will join in condemning unreservedly the practice which prevailed last century of deciding questions of poisoning in such circumstances from symptoms alone. But modern authors appear to have overstepped the mark, when they hold that the rule against deciding from symptoms does not admit of any exceptions. For there are cases of poisoning with arsenic, not numerous certainly, yet not very uncommon neither, which can hardly be confounded with natural disease; and, what is of some consequence, they are precisely those in which the power of deciding from symptoms alone is most required, because chemical evidence is almost always wanting. Either the peculiar combination of the symptoms is such as cannot arise from natural causes, so far at least as physicians are acquainted with them: or these symptoms occur under collateral circumstances, which put natural causes almost or altogether out of the question.

Thus, let the medical jurist consider in the first place, the symptoms occasionally observed in those who survive five, six or ten days; let him exclude for the present the secondary nervous affections; and instead of a compounded description, which may be objected to as apt to convey a false and exaggerated idea of the facts, let him take an actual example. In a paper by Dr. Bachmann on some cases of poisoning with arsenic, there is a minute account of the case of a lady who was poisoned by her maid with fly-powder and white arsenic, and whose symptoms were those of universal inflammation of the mucous membranes. After suffering two days from retching and vomiting, colic pains and purging, these symptoms suddenly became more violent, and attended with oppressed breathing and hoarseness so that she could hardly make herself be heard,—with vesicles on the palate, burning pain in the throat, and excessive difficulty in swallowing,—with spasm and pain of the bladder in passing water,—and with extreme feebleness of the pulse. Three days afterwards the symptoms increased still more. She complained of intolerable burning and spasms of the throat, which, as well as the mouth, was excessively inflamed,—of violent burning pain in the stomach and bowels,—of burning in the fundament and genitals, both of which were inflamed even to gangrene,—of indescribable anxiety and anguish about the heart; and she died the following day, death being preceded by subsultus, delirium, and insensibility.[^[711]] Or take the case in the trial of Miss Blandy. On two successive evenings, immediately after taking some gruel which had been prepared by the prisoner, Mr. Blandy was attacked with pricking and burning of the tongue, throat, stomach, and bowels, and with vomiting and purging. Five days after, when the symptoms were fully formed, he had inflamed pimples round the lips, and a sense of burning in the mouth; the nostrils were similarly affected; the eyes were bloodshot and affected with burning pain; the tongue was swollen, the throat red and excoriated, and in both there was a tormenting sense of burning; he had likewise swelling, with pricking and burning pain of the belly; excoriations and ulcers around the anus and intolerable burning there; vomiting and bloody diarrhœa; a low, tremulous pulse, laborious respiration, and great difficulty in speaking and swallowing. In this state he lingered several days, death supervening nine days after the first suspected basin of gruel was taken.[^[712]] Can the symptoms, in these two cases, attacking, as they did, at one and the same time, the whole mucous membranes, be imitated by any natural combination of symptoms? Viewing the endless variety and wonderful complexity of the phenomena of disease, the practitioner will probably, and with justice, reply that a natural combination of the kind is possible. But if his attention is confined, as in strictures it ought to real occurrences,—if he is required to speak only from actual experience, personal or derived, it is exceedingly questionable whether any one could say he had ever seen or read of such a case. At all events, if a medical witness had to give his opinion from symptoms only in such a case as that of Mr. Blandy, or that described by Bachmann, he would certainly be justified in declaring that poisoning was highly probable; and, admitting general poisoning to be proved, he would, it is likely, fix on arsenic as the substance which could most easily produce the effects.

Let him next, however, take also into consideration the nervous affections that sometimes either immediately follow the inflammation of the mucous membranes, or become united with it when it has existed a few days; and confining his attention still to actual occurrences, let him reflect on the symptoms in Dr. Roget’s case, in which there was first violent inflammation of the whole alimentary canal, and then regular and obstinate epilepsy (p. [245]), or on those in Dehaen’s patient, in whom the nervous disorder was partial palsy (p. [247]). On reconsidering these narratives, still greater reason will appear for doubting whether such a combination of simultaneous, and in the present instance also consecutive symptoms, ever arise from natural causes. It is difficult to conceive a fortuitous concurrence of natural diseases producing at the same moment that variety and complexity of disorder which occur in the primary stage of the cases alluded to; and it would surely be a still more extraordinary combination which should farther add the supervention of epilepsy or partial palsy from a natural cause, at the exact period at which it appears as the secondary stage of poisoning with arsenic. All that any practitioner could say is, that a concurrence of the kind is within the bounds of possibility. He must be compelled to admit that it is in the highest degree improbable, and likewise that it could hardly take place from natural causes without the real causes of the symptoms being clearly indicated.

But to conclude, there are likewise collateral circumstances connected with the symptoms, which, taken along with the symptoms themselves, will sometimes place the fact of poisoning with arsenic beyond the reach of a doubt. Thus, if a person were taken several times ill with symptoms of general inflammation of the mucous membranes, after partaking each time of a suspected article of food or drink, the proof of the administration of arsenic would be very strong indeed; and it would be unimpeachable if at length a nervous affection succeeded at the usual period. Or above all, suppose several persons, who have partaken of the same dish, are seized about the same time with nearly the same symptoms of irritation of the mucous membranes. The proof of general poisoning would then be unequivocal. And if one or more of them should afterwards suffer from a nervous disorder, little hesitation ought to be felt in declaring that arsenic is the only poison which could have caused their complaints.

These views are of more practical consequence than may at first sight be thought. The doctrine which has been here espoused might have been applied to decide two criminal cases which at the time made a great noise in this country. One was the case of Eliza Fenning (p. [245]). Here five persons were simultaneously attacked with symptoms, more or less violent, of inflammation of the whole alimentary canal; and in two of them epileptic convulsions appeared before the inflammatory symptoms departed. The other was the case of George Thom (p. [247]). Here four persons were at one and the same time seized with the primary symptoms in an aggravated form; and in two of them, as these symptoms abated, obstinate partial palsy came on. On both trials, then, it might have been stated from the symptoms alone that poison had been given, and that arsenic was the only poison hitherto known to be capable of producing such effects.

In applying this doctrine to parallel instances two precautions must be attended to. On the one hand, care must be taken to ascertain, as may always be done, that the simultaneous symptoms of general irritation in the alimentary canal, arising soon after a meal, are not owing to unsound meat having been used in preparing it. And on the other hand, which is of more consequence, the symptoms on which so important an opinion is founded, must be strongly marked and well ascertained by a competent person. The signs of irritation in the mucous membranes must be really general and unequivocal; and those of a disorder of the nervous system must be likewise developed characteristically. Care must be taken in particular to distinguish symptoms of the latter class from others which approach to them in nature, and are the ordinary sequels of natural disease: for example, the true palsy caused by arsenic must not be confounded with the numbness and racking pains in the limbs, which occasionally succeed cholera.

With these precautions the evidence from symptoms may in certain cases be decisive of the question of poisoning with arsenic. And it is of moment to observe, as has been already hinted, that, although such cases are numerous, they are precisely of the kind in which it is most essential to the ends of justice that the symptoms should, if possible, supply evidence enough to direct the judgment; for the characteristic symptoms referred to occur chiefly when the patient either recovers or survives many days, and where consequently the chemical evidence, usually procured from the examination of the contents of the stomach, is almost always wanting.

Section III.—Of the Morbid Appearances caused by Arsenic.

The morbid appearances caused by arsenic will next require some details. In treating of them the same plan will be pursued as in the preceding section: the various morbid appearances left by it will first be mentioned in their order; and the subject will then be wound up with some remarks on the force of the evidence from these appearances, as they are usually combined in actual cases.

In the first instance, there are some cases in which little or no morbid appearance is to be seen at all. These all belong to the second variety of poisoning, which is characterized by the absence of local inflammation, and the presence of symptoms indicating an action on the heart, or some other remote organ. In such circumstances death takes place before a sufficient interval has elapsed for inflammation to be developed.

Several examples of the absence of diseased appearances in the dead body are to be found in authors. Thus in Chaussier’s case formerly quoted (p. [243]), in that related by Metzger (p. [242]), in another related by Etmuller, which was fatal in twelve hours,[^[713]] and in a fourth related by Professor Wagner of Berlin, where life was also prolonged for twelve hours under incessant vomiting,[^[714]] there was positively no morbid alteration at all. Such was also the state of the whole alimentary canal in the extraordinary case related by Orfila (p. [243]). In the case quoted from the Medical and Physical Journal (p. [242]), there was merely a slight redness at the pyloric end of the stomach. In the case of the American grocer too, there was only a little redness. In Mr. Wright’s case (p. [243]), there was scarcely any morbid appearance,—nothing more than two small vascular spots and a minute ecchymosis. In that which fell under my own notice (p. [242]), the villous coat of the stomach was of natural firmness, and had an exceedingly faint mottled-cherry-red tint, barely perceptible in a strong light; and the rest of the alimentary canal, as well as the body generally, was quite healthy.

Although in these examples the morbid appearances were trifling or undistinguishable, it must not be supposed that the same happens in all cases of rapid death from arsenic. In Gérard’s case, where the usual irritant symptoms were wanting, and which proved fatal in five hours, there was dark redness of the whole villous coat of the stomach. In Mr. Holland’s case, fatal in eight or nine hours (p. [243]), the stomach was of an intense purple colour at its pyloric end, and contained bloody mucus; and the mucous coat of the cœcum presented extensive softening and congestion. Mr. Alfred Taylor refers to three cases observed by Mr. Forster of Huntingdon, in which the mucous coat of the stomach was highly inflamed, though death took place in 6½, 3½, and 2 hours only:[^[715]] in Mr. Hewson’s case, fatal in five hours, the whole stomach was exceedingly vascular, and presented both spots of extravasation, and several small erosions (p. [201]). In a case alluded to at p. [239] as having fallen under my own observation, and which was also fatal in five hours, the whole villous coat of the stomach was intensely red, except where the folds of the rugæ protected it from contact with the poison; and the prominences of the rugæ presented corroded spots of ecchymosis. In Dr. Dymock’s case, fatal in two hours and a half, the stomach, which I had an opportunity of examining, presented on its mucous coat many scarlet patches, and here and there a purplish appearance (p. [240]). Lastly, an instance is related by Pyl of this poison proving fatal in three hours, and leaving nevertheless in the dead body distinct signs of inflammation in the stomach.[^[716]]

In the ordinary cases in which death is delayed till the second day or later, a considerable variety of diseased appearances has been observed. They are the different changes of structure arising from inflammation in the alimentary canal, in the organs of the chest, and in the organs of generation—together with certain alterations in the state of the blood and condition of the body generally.

The first set of appearances to be mentioned are those indicating inflammation of the alimentary canal, viz., redness of the throat and gullet,—redness of the villous and peritonæal coats of the stomach, blackness of its villous coat from extravasation of blood into it, softening of the villous coat, ulceration of that as well as of the other coats, effusion of coagulable lymph on the inner surface of the stomach, extravasation of blood among its contents,—finally, redness and ulceration of the duodenum and other parts of the intestinal canal, and more particularly of the rectum; to which may also be added, though not properly a morbid phenomenon, certain appearances put on by the arsenic which remains undischarged.

Redness of the throat and gullet is not common, at least it does not often occur in the descriptions of cases. Jaeger, however, says that in his experiments he usually found redness at the upper and purplish stripes at the lower end of the gullet:[^[717]] and Dr. Campbell likewise found the gullet red in animals,[^[718]] Similar appearances have also been remarked in man. In the case of a man who lived eight days, Dr. Murray found the gullet very red;[^[719]] in that of a woman who lived scarce seven hours, Dr. Booth observed the gullet inflamed downwards very nearly to the cardia;[^[720]] and Wildberg has reported two cases of the same nature, in one of which it is worthy of remark that the poisoning lasted only six hours.[^[721]] On the whole, it appears probable that inflammation of the throat and gullet would be found more frequently in the reports of cases, if it was more carefully looked for.

Redness of the inner coat of the stomach is a pretty constant effect of arsenic, when the case is not very rapid. All the varieties of redness, formerly mentioned among the effects of the irritant poisons generally, may be produced by arsenic. There is nothing, however, in the redness caused by this poison, any more than in the redness of inflammation generally, by which it is to be distinguished from the pseudo-morbid varieties. (See p. [110].)

It is singular, that, however severe the inflammation of the inner membrane of the stomach may be, inflammatory redness of the peritonæal coat is seldom found. Yet inflammatory vascularity does occur sometimes on the peritonæal coat. Sproegel found it in animals;[^[722]] and it was present in the case of the girl Warden, whose death gave rise to the trial of Mrs. Smith.[^[723]] Dr. Nissen, a Danish physician, has related another case in which the external coat of the stomach appeared as if minutely injected with wax. But the patient had been attacked with incarcerated hernia during the progress of his illness, and the whole peritonæal membrane was in consequence inflamed.[^[724]] A common appearance when the internal inflammation is well marked, and one often unwarily put down as inflammation of the peritonæum, is turgescence of the external veins, sometimes so great as to make the stomach look livid.

Blackness of the villous coat from effusion of altered blood into its texture is sometimes met with. When the colour is brownish-black, or grayish-black, not merely reddish-black, when the inner membrane is elevated into firm knots or ridges by the effusion, and the black spots are surrounded by vascularity or other signs of reaction, the appearances strongly indicate violent irritation. I have already said that such appearances are never imitated by any pseudo-morbid phenomenon.

One of the most remarkable appearances occasionally observed in the stomach in those instances where the body has been buried for at least some weeks before examination, is the presence of bright yellow patches, of various sizes, which appear as if painted with gamboge, and obviously arise from the oxide of arsenic diffused throughout the tissues having been decomposed and converted into sulphuret of arsenic by the sulphuretted-hydrogen disengaged during putrefaction. I have witnessed this appearance in several cases. In the case mentioned at p. [247], where the body had been buried twenty days, numerous brilliant yellow patches were visible on the villous coat of the stomach. In the case of a female who was poisoned about the same time with that man, and, as was suspected, by the same individual, the body was not examined till three months after interment; and here broad, bright, yellow patches, disappearing under the action of ammonia, were found under the peritonæal coat of the left end of the stomach, the adjoining great intestine, and also the muscular parietes of the abdomen. In the case of Mr. Gilmour, for whose murder his wife was tried a few months ago in this city, but acquitted,—and who undoubtedly died of poisoning with arsenic, howsoever administered,—there were found fourteen weeks after death numerous yellow streaks and patches both on the inner surface of the stomach, on its outer surface under the peritonæum, on the adjoining transverse colon, and on the small intestines in contact with the stomach. From these and other parallel facts which have been occasionally noticed by the periodical press, it seems probable that the appearance in question is common in bodies which have been some time buried. It is an extremely important part of the pathological evidence. I doubt whether natural causes can occasion any appearance similar to it. And indeed, what is it but the effect of a chemical test applied to the poison by nature?

The next appearance which may be mentioned is unnatural softness of the villous coat of the stomach. This coat has certainly been often found, after death from arsenic, unusually soft, brittle, and easily separable with the nail.[^[725]] But the same state occurs in dead bodies so often and so unconnected with previous symptoms of irritation in the stomach, that it cannot with any certainty be assumed as the effect of irritation when it is found subsequently to such symptoms. So far from softening and brittleness being a necessary effect of the irritation produced by arsenic, it is a fact that a condition precisely the reverse has been also noticed. In a case which I examined, the villous coat, except where it had been disintegrated by effused blood and ulceration, was strong and firm; and the rugæ were thickened, raised and corrugated, as if seared with a hot iron.[^[726]] Metzger once found the mucous membrane dense, thickened, and the rugæ like thick cords.[^[727]] Pyl too once met with the same appearance, and ascribes the thickening to gorging of vessels;[^[728]] and in a case related by Dr. Wood of Dumfries, where I had an opportunity of examining the stomach, this appearance was present in a remarkable degree, and it clearly arose from elevation of the villous coat by effusion of blood under it.[^[729]] Remer, in his edition of Metzger’s Medical Jurisprudence, says he once met with an instance where the stomach was shrivelled like a bladder subjected to boiling water.[^[730]]

Sometimes the villous and also more rarely the other coats of the stomach are found actually destroyed and removed in scattered spots and patches. This loss of substance is occasionally owing to the same action which causes softening and brittleness of the villous coat,—the action, however, having been so intense as to cause gelatinization. That such is the nature of the process appears from the breach in the membrane being surrounded by gelatinized tissue, and not by an areola of inflammatory redness. Of this species of destruction of the coats I have seen a characteristic example.[^[731]] But in other cases the loss of substance is owing to a process of ordinary ulceration, as is proved by the little cavities having a notched irregular shape, and being surrounded both by a red areola and a margin of firm tissue. This was the character of the ulcers in the case of Warden, which I have described elsewhere.[^[732]] Destruction of the coats of the stomach by ulceration is not a very common consequence of poisoning with arsenic, as death frequently takes place before that process can be established. It does not often occur, unless the patient survive nearly two days. Mr. Alfred Taylor, however, mentions a case fatal in seventeen hours where he found ulceration of the stomach, and another fatal in ten hours where several small ulcers were seen on the lesser curvature, and two nearly circular ones as big as a sixpence.[^[733]] Mr. Hewson too informs me he found many eroded spots even in his case which proved fatal in five hours (p. [56]). I suspect, however, that spots of healthy membrane surrounded by vascular redness are sometimes mistaken for ulcers in such cases; for indeed nothing can more exactly resemble them. In many general works on Medical Jurisprudence, and in some express treatises on arsenic, it is stated that this poison may cause complete perforation of the stomach.[^[734]] But this effect is exceedingly rare. I have related one distinct example of it;[^[735]] Professor Foderé has briefly alluded to a case he witnessed which proved fatal in two days and a half;[^[736]] I have likewise found in an account of a trial in North America, an instance in which the stomach was perforated by numerous small holes, so that when held before the light it appeared as if riddled like a sieve;[^[737]] but I have not been able to find in medical authors any farther authority for the general statement. Destruction of the coats of the stomach as produced by arsenic has been variously described by authors under the terms erosion, corrosion, dissolution, ulceration. But the correct mode of describing it appears to be by the terms gelatinization, or ulceration, according to the nature of the diseased action by which it is induced. At all events it is necessary to beware of being misled by the terms erosion, corrosion, and the like, which all convey the idea of a chemical action; while it is well ascertained that a chemical action either does not exist at all between arsenic and the animal tissues, or, if it has existence, tends to harden and condense rather than to dissolve or corrode them. Arsenic is not a corrosive.

Another species of destruction of the coats of the stomach, which will require a little notice, is sloughing or gangrene. This appearance occurs frequently in the narratives of the older writers; but it has not been enumerated in the list of morbid appearances at the commencement of this section, because its existence as one of the effects of arsenic is problematical. It has not been witnessed so far as I know by any recent good authority. Those who have mentioned it have probably been misled by the appearance put on by the black extravasated patches, when they are accompanied by disintegration of the villous coat and effusion of clots of black blood on its surface—an appearance which resembles gangrene closely in everything but the fetor. Sir B. Brodie has stated that Mr. John Hunter has preserved in his museum, as an example of a slough of the villous coat caused by arsenic, which turned out on examination to be nothing else than an adhering clot.[^[738]] It is clear too, that, when Mr. James speaks of having found “several gangrenous patches” on the villous coat of the stomach, and “patches of sphacelus” in the intestines, on examining the body of a notorious French criminal, Soufflard, who poisoned himself with arsenic in prison in 1839, he mistook for gangrene what was merely extravasation; for the man lived only twelve hours.[^[739]]

Various secretions have been found on the inner surface of the stomach. The mucous secretion of the inner membrane is generally increased in quantity. Frequently it is thin, but viscid, as in its natural state; but sometimes it is both abundant and solid, as if coagulated; and then it forms either a uniform attached pellicle, or loose shreds floating among the contents.[^[740]] In both forms it has been mistaken for the mucous membrane itself. I believe this increased secretion and preternatural firmness of the gastric mucus cannot take place without some irritating agent being applied to the stomach. Both may occur without any other sign of inflammation in the mucous membrane. In a case of suicide after seduction which came under my notice in this city in 1843, and which proved fatal in five hours [p. [239]], the mucus in the stomach, which was very abundant, put on the appearance of curdled milk, owing to its being rendered opaque and white by the large quantity of finely powdered arsenic diffused through it; and it was actually mistaken for curdled milk by several medical men.—Sometimes the matter effused is true coagulable lymph. This is rarely seen as the effect of arsenic. I have remarked it, however, very distinctly in dogs, and Dr. Baillie saw it once in the human subject.[^[741]] It is of course quite decisive of the presence of inflammation. It is known from tough mucus, to which it bears some resemblance, by its reticulated disposition, and by the threads of the reticulation corresponding with inflamed lines on the stomach beneath.

Another very common appearance is the presence of a sanguinolent fluid, or even actual blood in the cavity of the stomach. In several of the cases which have come under my own notice, the subject of analysis was a thick, dirty brownish-red fluid, evidently containing a large proportion of blood; and many other examples of the same nature are on record.[^[742]] In Laborde’s case formerly mentioned actual clots were found among the contents; in the instance of a woman who died in five days, as related by Zittmann, half a pound of coagulated blood was found in the stomach;[^[743]] and in another case mentioned by Professor Bernt, the stomach contained no less than three pounds of black ichor mixed with clots of blood.[^[744]] A good deal of reliance has been placed on bloody effusion in proof of the administration of arsenic or some other active irritant. It is of some importance, as it appears not to be an effect of that irritation which causes cholera.

Among the appearances observed in the stomach the presence of arsenic may be included, though not properly speaking a morbid appearance. Under the head of the medical evidence of poisoning generally it was stated, that many causes conspire to remove from the stomach during life poisons which have actually caused death. In addition to the illustrative cases there alluded to, I may here also refer to an interesting case communicated to me by Mr. J. H. Stallard, and already noticed for a different purpose [p. [235]]. Arsenic in no large quantity had been swallowed in tea, and death took place in four hours only. Here none of the poison could be detected by Marsh’s process, either in the contents of the stomach, or in its tissues, or in the liver.—In the instance of arsenic, however, the operation of the causes which tend to remove the poison is prevented by various circumstances, in particular by its insolubility and firm adhesion to the stomach. Hence it happens, that even after long-continued vomiting a portion still generally remains behind, either in the contents of the stomach or in its tissues. Sometimes the arsenic exists dissolved in the contents; more commonly it is present there in the solid form; and is then either in loose particles, or enveloped in coagulated mucus,[^[745]] or in little clots of blood,[^[746]] or is wrapped up in the more solid parts of the contents.[^[747]] Frequently it adheres to the coats of the stomach, and is then either scattered in the form of fine dust or collected in little knots. The adhering particles are always covered by mucus; they are often surrounded by redness of the membrane or by effused blood; and sometimes they are imbedded in little ulcers.—A remarkable appearance which the arsenic sometimes puts on is a brilliant yellowness of its surface, owing to its conversion into the sulphuret. This appearance existed in six cases which have come under my own notice, first in one related in the Edinburgh Medico-Chirurgical Transactions,[^[748]] next in the instance of Margaret Warden,[^[749]] again in the case of a young woman whose death gave rise to the trial of John Lovie held at Aberdeen in the Autumn Circuit of 1827, again in a case described by Dr. Wood, which I had an opportunity of examining;[^[750]] and lastly, in two others which I had occasion to examine in 1842 and 1843. In one of these, the case of Mr. Gilmour, adverted to at p. [265], Drs. Wylie and M’Kinlay, who examined the body in the country, found the inner surface of the stomach thickly sprinkled with small yellow particles, some of which were very bright. In all of these cases oxide was found, as well as the sulphuret of arsenic. In the case related by Dr. Nissen [p. [264]], a similar yellow appearance, observed on the surface of the arsenic, was ascribed with justice to the action of sulphuretted hydrogen-water, which had been given as an antidote during life.[^[751]] In a very important case examined here a few years ago by my colleague Dr. Traill, and which will be noticed more particularly for a different purpose afterwards, this conversion of the oxide into sulphuret had taken place to a great extent [p. [277]]. In every instance of the kind yet examined, however, the conversion has been only partial, so that a large proportion of oxide could easily be detected by the usual process.

Care must be taken not hastily to consider as arsenic every white powder which may be found lining the inside of the stomach. Many other white powders may obtain entrance from without; and besides, small, white, shining, pulverulent scales, not unlike finely powdered arsenic, but rarely composed of animal matter, sometimes form naturally on the mucous coat of the stomach and intestines. In a medico-legal report published a few years ago, Professor Orfila has noticed two instances in which these scales were mistaken for arsenic;[^[752]] in another published not long after he mentions that he found white particles which crackled when bruised, and appeared brilliant before the microscope, and which nevertheless were not arsenic.[^[753]] Buchner too says he is acquainted with an instance where, in a medical inspection on account of a suspicion of poisoning, the villous coat of the stomach was found lined with a white granular substance which presented the properties of a fat and contained no mineral admixture;[^[754]] and in the case of Warden I remarked a similar appearance, which, as arsenic was found in the stomach, I was disposed to consider a sprinkling of that poison, until the contrary was ascertained by analysis. The present caution, therefore, is not superfluous.

In a few cases the stomach is the only situation where morbid appearances are visible, even though life has been prolonged for so much as two days. This state of matters is well exemplified by a French case of death in forty-three hours, where the stomach presented much redness and extravasated patches, but where the intestines, the larynx and the contents of the head and chest were in a natural condition.[^[755]] Such limitation, however, of the diseased appearances are rare.

Redness of the mucous membrane of the intestines is often present when the stomach is much inflamed. Dissolution of the mucous coat is much less frequent in the intestines than in the stomach. Ulceration occasionally occurs in lingering cases. In the case of Mitchell, which has been several times alluded to, the inner coat of the duodenum was dark-red, pulpy, thickened, easily separable; and on a spot as big as a crown piece, both the inner and the muscular coats were wanting.[^[756]] Perforation of the small intestine was found in a case communicated to me by Mr. Sandell, and detailed at page [277]. But as the person survived only eight hours, and had laboured under symptoms of disease in the bowels for some days before taking the arsenic, it is unlikely that this appearance, which has not been observed, to my knowledge, in any other instance, arose from the action of the poison.

The signs of inflammation are seldom distinct in the small intestines much lower down than the extremity of the duodenum; and they do not often affect the colon. But the rectum is sometimes much inflamed, though the colon, and more particularly the small intestines, are not. Dr. Male mentions, that in man he has found the rectum abraded, ulcerated, and even redder than the stomach itself;[^[757]] and Dr. Baillie also notices two cases in which the lower end of the rectum was ulcerated.[^[758]] A common appearance in lingering cases is excoriation of the anus,[^[759]] and it is said that even gangrene has been produced.[^[760]]

A late writer draws attention to the fact that in the only two fatal cases he had seen the whole colon was contracted to an extraordinary degree;[^[761]] and this state is mentioned in other cases. The appearance deserves notice; but of course whatever empties the colon thoroughly will have the same effect.

The chief appearances in the alimentary canal have now been mentioned. The next quarter in which deceased appearances are to be met with is the cavity of the chest. Here are sometimes seen redness of the pleura, redness and congestion of the lungs, redness of the inner surface of the heart, and redness of the lining membrane of the windpipe.

Redness of the diaphragmatic part of the pleura, or even of the whole of that membrane, has been at times observed; as one would expect, indeed, from the pectoral symptoms which occasionally prevail during life. Inflammation of the lungs themselves has also been noticed. Dr. Campbell twice found great congestion of blood in the lungs of animals poisoned by the application of arsenic outwardly.[^[762]] Sproegel likewise found the pleura, pericardium, and whole lungs deeply inflamed in animals.[^[763]] Dr. Venables found the pleura of a bright crimson colour in some poultry maliciously poisoned with arsenic,—more redness there indeed than in the stomach.[^[764]] Mr. James says that in his experiments on animals he constantly found the lungs much gorged with blood, unless when death occurred quickly; but that he could see no evidence of the congestion being inflammatory.[^[765]] A distinct example of advanced pneumonia in man is related in Pyl’s Magazine: the patient died after vomiting and purging incessantly for eight days; and on dissection the lungs were found “in the highest state of inflammation; and so congested as to resemble a lump of clotted blood.”[^[766]] A distinct case of the same nature is related in Henke’s Journal; this patient had obvious pneumonic symptoms during life; and in the dead body the lungs were found so gorged, that, on being cut into, nothing could be seen but clotted blood in their cellular structure.[^[767]] In a case formerly adverted to [p. [252]] of death from arsenic applied externally for scirrhus, excessive congestion was found in the lungs, “both lungs being completely gorged with blood, and presenting all the characters of pulmonary apoplexy.”[^[768]] In another described by Dr. Booth of Birmingham, where death occurred in seven hours only, the lungs presented sufficient congestion to have completely impeded respiration.[^[769]]

It has been alleged that the inner surface of the heart has been found red from inflammation. In a case examined judicially at Paris by Orfila, the left cavities of the heart were of a mottled red hue, and in the ventricle were seen many small crimson specks which penetrated into the muscular part of the parietes. The right cavities had a deep reddish-black tint, and the ventricle of that side contained specks like those in the other, but more faint. Orfila adds, that he had previously seen the same appearance in animals.[^[770]] These observations are not satisfactory. There is no evidence that the observer drew the distinction between the redness of inflammation, and that produced by the dyeing of the membrane with blood after death. The subject was afterwards brought before the Royal Academy of Medicine at Paris by M. Godard, who had also observed the appearance in question in a person killed by arsenic, and who dwelt strongly on it as characteristic of this species of poisoning. It was distinctly proved, however, by many members present that the appearance arises from various other causes.[^[771]]

The inner membrane of the windpipe is said to be sometimes affected with inflammatory redness. Jaeger found it so in animals;[^[772]] and the symptoms referrible to the windpipe during life would lead us to expect the same thing in man.

The organs of generation are occasionally affected. The penis in the male and the labia in the female have been found distended and black; in an interesting case related by Bachmann the external parts of generation (in a female) were surrounded by gangrene;[^[773]] and in a case related in Pyl’s collection the inside of the uterus and Fallopian tubes was inflamed.[^[774]] It is probable that signs of inflammation in the internal organs of generation will be found if there have been corresponding symptoms during life. But in truth this part of the pathology of poisoning with arsenic has not been particularly attended to.

To complete this account of the morbid appearances of the mucous membranes, it may be added that the conjunctiva of the eyes frequently presents vascularity and spots of extravasation.[^[775]]

It now only remains, under the head of the morbid appearances produced by arsenic, to mention certain alterations that are said to take place in the state of the blood and general condition of the body.

With regard to the state of the blood Sir B. Brodie observes in general terms, that in animals killed by arsenic it is commonly fluid.[^[776]] Harles, on the authority of Wepfer, Sproegel, and Jaeger, says it is black, semi-gelatinous, and sometimes pultaceous.[^[777]] Novati alleges that the blood after death is without exception black and liquid as after cholera, of a blackish-purple tint that colours linen reddish-brown, viscid, opaque, and without any trace of coagulation.[^[778]] In a fatal case related by Wildberg the blood was everywhere fluid.[^[779]] This condition, however, is not uniform; for Dr. Campbell found the blood coagulated in the heart of a rabbit;[^[780]] and Wepfer found it also coagulated in the dog.[^[781]]

It has been stated by some authors in medical jurisprudence that the dead body occasionally exhales an aliaceous odour, resembling that of sublimed arsenic. This is a very questionable statement. The only fact of the kind worth mentioning is one brought forward by Dr. Klanck, as occurring in the course of certain experiments, which will presently be noticed, on the antiseptic virtues of arsenic. Several animals which had been killed with arsenic are said to have exhaled an odour like that of sublimed arsenic from three to eight weeks after death.[^[782]]

A great discordance of opinion at one time prevailed among authors, as to the influence of arsenic on the putrefactive process in the bodies of those poisoned with it. The vulgar idea, borrowed probably from the ancient classics, that the bodies of those who have been poisoned decay rapidly, was till lately the prevalent doctrine of medical men, and even of medical jurists; and it was applied to arsenic as well as other poisons. Even so lately as 1776 we find Gmelin stating in his History of Mineral Poisons, that the bodies of those who have died of arsenic pass rapidly into putrefaction, that the nails and hair often fall off the day after death, and that almost the whole body quickly liquefies into a pulp.[^[783]] A similar statement has been made in 1795 by a respectable author, Dr. John Johnstone.[^[784]] It appears that this rapid or premature decay does really occur in some instances. Thus in a case related by Plattner of death from arsenic administered as a seasoning for mushrooms, the body had a very putrid odour the day after death.[^[785]] Loebel also asserts he found by experiments on animals, that after death from arsenic putrefaction took place rapidly, even in very cold weather.[^[786]]

In other instances the body probably decays in the usual manner. For example, in Rust’s Magazin is related the case of a child who died in six hours of poisoning with arsenic, and in whose body, fourteen days after death, the integuments were found considerably advanced in putrefaction, and the liver and kidneys beginning to soften.[^[787]] In the case of a man who died in two days, and in whose body arsenic was found by MM. Chapeau and Parisel throughout many of the tissues, “putrefaction was so far advanced eight days after death as to render the examination of parts obscure.”[^[788]] And in the course of some experiments on dogs poisoned with the oxide Dr. Seeman found the usual changes after five months’ interment.[^[789]]

But it has been proved in recent times that in general arsenic has rather the contrary tendency—that, besides the antiseptic virtues which it has been long known to exert when directly applied in moderate quantity to animal substances, it also possesses the singular property of enabling the bodies of men and animals poisoned with it both to resist decay unusually long, and to decay in an unusual manner. The observations and inquiries which have been made abroad on this subject were little known any where else than in Germany before the publication of the earlier editions of the present work; but parallel examples have been since met with both in Britain and France; and in this country the importance of the subject is generally appreciated.

The first occasion on which the antiseptic property of arsenic was brought under public notice was about the beginning of the present century, in the course of the trial of the widow of a certain state-councillor, Ursinus of Berlin. Some time before that Dr. Welper, then medical inspector in the Prussian capital, having remarked that the body of a person poisoned with arsenic remained quite fresh for a whole week in summer, he attended carefully to the subject at every opportunity, and invariably, he says, found that the body resisted putrefaction. Not long after making this remark, he was concerned in 1803, by virtue of his office, in the investigations in the case of the widow Ursinus. This lady having been discovered in an attempt to poison her servant, suspicions arose regarding the previous sudden death of three persons in her family, her husband, a young officer who had carried on an amour with her, and an aunt from whom she derived an inheritance. They had all died in mysterious circumstances, and the lady had been their only nurse. Dr. Welper disinterred the bodies of the husband and aunt, which had been buried, the former two years and a half before at Berlin, the latter half a year afterwards at Charlottenberg; and he found them not putrid, but dried up; and specks of an appearance, which is described as being gangrene, but which was probably warty extravasation, were visible in the stomach. Arsenic could not be detected.

He afterwards got Dr. Klanck, his acquaintance, to make some express experiments on animals; and the results were strikingly conformable. In dogs poisoned with arsenic and left for two months sometimes buried in a damp cellar, sometimes exposed to the air of the cellar, the flesh and alimentary canal were red and fresh, as if pickled; and though the place where the carcases were subsequently buried again was flooded for eight months after, the intestines were eventually found entire and red, the fat converted into adipocire, and most of the muscles unaltered,—those only being soft and greasy which were directly acted on by the water. From a set of comparative experiments which were made on dogs killed by blows, or poisoned by corrosive sublimate, or by opium, Klanck found, that, after being buried in the same place, and for the same space of time the whole soft parts of the carcases were converted into a greasy mass. In a subsequent year he repeated his experiments, the bodies, however, being this time left exposed to the air of the cellar. The experiments were commenced in the month of August. In ten days there appeared slight signs of incipient putrefaction; a faint putrid smell was exhaled, and all flies that settled on the carcase died. This state continued for eight or ten weeks without increasing. After that the soft parts began to grow firmer and drier, and at the same time the putrid odour was succeeded by a smell like that of garlic, which became insupportably strong when the carcases were removed into warm air. The bodies, three years afterwards, still continued dry and undecayed.[^[790]]

A similar set of facts was again brought before the public between 1809 and 1811, during the criminal proceedings in a case like that of the widow Ursinus, tried first at Bayreuth and afterwards by appeal at Munich. A lady near Bayreuth died of five days’ illness, under symptoms of violent general irritation of the alimentary canal. Some months afterwards a variety of circumstances having raised a suspicion that she had been poisoned by her maid, Margaretha Zwanziger, a judicial investigation was set on foot; the consequence of which was, that the same woman came under suspicion of having also previously poisoned another lady and a gentleman with whom she had been successively in service. The bodies of the three people were accordingly disinterred, one of them five months, another six months, and the third fourteen months after death. In all of them the external parts were not properly speaking putrid, but hard, cheesy, or adipocirous; in the last two the stomach and intestines were so entire as to allow of their being tied, taken out, cut up, and handled; and in one a sloughy spot was found in the region of the pylorus. Arsenic was detected in two of the bodies by Rose’s process of analysis.[^[791]]

The next example to the same effect which will be mentioned is perhaps the most satisfactory of all, because it was the result of an express experiment on the human subject. Dr. Kelch of Königsberg buried the internal organs of a man who had died of arsenic, and whose body had remained without burial till the external parts had begun to decay; and on examining the stomach and intestines five months after, he found that the hamper in which they were contained was very rotten; but that “they had a peculiar smell, quite different from that of putrid bowels, were not yet acted on by putrefaction, but as fresh as when first taken from the body, and might have served to make preparations. They had lost nothing of their colour, glimmer, or firmness. The inflamed spots on the stomach had not disappeared, and the small intestines also showed in some places the inflammatory redness unaltered.”[^[792]]

In a recent French case, although the degree of preservation was less remarkable, the other circumstances are so striking as to render it well worthy of notice. In this instance the body was disinterred after having been seven years in the ground, in a high situation and sandy soil. The coffin, which was of oak, had become dry and brittle, and no moisture appeared on the inside. The body was entire: the head, trunk, and limbs retained their situation; but the organs of the chest and belly were converted into a brown soft mass of the consistence of plaster, which lay on each side of the spine. In this mass MM. Ozanam and Idt, the medical inspectors, succeeded in discovering by chemical analysis a considerable quantity of arsenic.[^[793]]

M. Ollivier describes another French case, where the body had been buried for three years, and was found so completely dried up that the trunk weighed only two pounds. The integuments were entire, dark-brown, and of a faint odour like decayed wood. The organs of the chest and belly were confounded together in a foliaceous membranous mass, in which the liver only could be distinguished, but in an exceedingly shrivelled state. Arsenic was detected in the membranous matter by MM. Barruel and Henri. The preservative power of the arsenic was promoted in this case by the sandy nature of the soil.[^[794]]

In the case of the girl Warden, which has been several times alluded to, the internal organs were also preserved somewhat in the same manner as in the German cases. The body had been buried three weeks; yet the mucous coat of the stomach and intestines, except on its mere surface, was very firm, and all the morbid appearances were consequently quite distinct. Nay, three weeks after disinterment, except that the vascularity had disappeared, the membranes and the appearances in them remained in the same state.[^[795]] A similar case has been recorded by Metzger. It is that of an old man who died of six hours’ illness, and in whose stomach three drachms of arsenic were found. The body had been kept ten days in February before burial, and was disinterred eight days after that; yet there was not the slightest sign of putrefaction any where.[^[796]] A parallel case was described by myself in the Edinburgh Medico-Chirurgical Transactions;[^[797]] and I have met with three others of the same kind since.

In a very important case, that of Mrs. Smith, which was made the subject of investigation at Bristol in December, 1834, the body was also found in a state of great preservation, modified, however, by adipocirous decomposition, owing to the presence of water in the coffin. The body had been fourteen months interred. The internal parts, especially of the head and neck, were here and there decayed somewhat or converted into adipocire, the muscles and internal organs entire, though more or less shrivelled, the alimentary tube remarkably preserved, “every part being almost as distinct as if the inspection had been made at a very short period after death,” “the mucous membrane sufficiently tenacious to be lifted by the forceps in as large flakes as usual;” and the reporters, Drs. Riley and Symonds, Messrs. Herapath and Kelson, seem to have had no difficulty in ascertaining the absence of vascularity, extravasation, or even abrasion of the inner membrane. Artificial orpiment, the preparation proved to have been given [see p. [225]], was found in the stomach by Mr. Herapath, and the quantity appeared to be about half a drachm.[^[798]]

A similar instance, very remarkable in all its circumstances, was investigated here in 1834 by my colleague Dr. Traill to whom I am indebted for the particulars. The master of a foreign vessel died in about twenty-four hours, apparently of malignant cholera, at a small port in the neighbourhood of Edinburgh: and the body was forthwith buried. A suspicion, however, having arisen in his native country that he had been poisoned by his mate, an inquiry was instituted at the request of the foreign government; and the body was disinterred five months after death. The face and neck was swollen, black, and decayed; but the rest of the body was quite free of the usual signs of putrefaction. The skin was white and firm, the muscles fresh, the lungs crepitating, the liver and spleen much shrivelled, the stomach and intestines entire throughout their whole tissues, and capable of being handled freely without injury. On the mucous coat of the stomach several dark patches of extravasation were found, likewise several spots and large patches which presented on their surface a firmly adhering bright yellow crust; and the contents of the stomach consisted of a considerable quantity of yellow sandy matter of the consistence of paste. The contents and adhering crusts were found to consist chiefly of oxide of arsenic partially converted into sulphuret. In this instance, as in that last described, the coffin contained water, owing to its having laid in a sandy soil resting on clay.

An important case of the same nature was communicated to me in 1843 by Mr. Sandell of Potton, Bedfordshire, and afterwards published by Mr. Hedly of Bedford. A man Dazley at Wrestlingford, affected with symptoms of gastro-enteric irritation for five or six days, was seized with sickness, vomiting, heat and constriction in the throat, and great weakness, about an hour after getting a white powder from his wife; and in eight hours he expired, without any suspicion of unfair usage arising at the time. Suspicions, however, being entertained afterwards, the body which had not been examined at first, was disinterred in five months, during the month of March. The countenance was so entire as to be recognisable. Adipocire had been formed in many places. The stomach and intestines were “in a most perfect state of preservation,” as if death had taken place only a few days previously. The stomach presented yellow patches on its outer and inner surface,—was generally red over its villous coat, which had also been abraded near the cardiac end,—and, together with the small intestines, was lined with white powder and contained more of it enveloped in much red mucus. This powder proved to be arsenic. About the middle of the small intestines a small ulcerated opening was found, through which some arsenic had escaped.[^[799]]

The following cases which have come under my own notice during the last five years are also worthy of observation. In a case submitted to me on the part of the crown in 1841, which has been adverted to above for another purpose [p. [265]], the body after being three months interred was found with the head and face decayed and putrid; but the muscular substance was little changed; and the inspectors were particularly struck with the state of preservation of the body, and also with the very distinct state of inflammation seen over almost the whole external and internal surfaces of the alimentary canal,—a description, the accuracy of which I had afterwards an opportunity of verifying. In the case of Mr. Gilmour (p. [265]), whose body had been buried 101 days, the external parts were more decayed; but the alimentary canal appeared equally entire both to the original inspectors, Drs. M’Kinlay and Wylie, and likewise to myself three weeks later. But the following instance, in which I was consulted in 1839, is the most remarkable one of the kind that has hitherto occurred to me; because the observations then made were the result of an express experiment in a medico-legal investigation. The history of this case, which arose from small doses of arsenic frequently administered, has been already given above in some detail [p. [250]]. Arsenic not having been detected in the contents or tissues of the stomach, and the trial of the individual suspected of giving the poison being necessarily postponed for some months, I recommended that a third examination of the body,—for it had been twice disinterred for inspection within ten days after death,—should be made at as distant an interval as possible, in order to ascertain whether it underwent preservation from decay. It was accordingly disinterred again, five months after death. It had an ammoniacal, but not a putrid odour. The skin was here and there covered with a thin sebaceous matter, at one or two places stripped of the epidermis, but for the most part natural in appearance, firm, and elastic. The nails were loose. The muscles of the head and near the tops of the scapulæ were adipocirous, on the chest and abdomen obscurely fibrous in texture and hardened, but elsewhere unaltered, and “in the lower extremities so perfect that they might have been used for an anatomical demonstration.” The liver and lungs were also in a state of good preservation, and the latter crepitated when cut. The other viscera had been removed at the previous examinations.

It may be added that the experiments of Klanck on dogs adverted to above have been more recently repeated by Hünefeld on rabbits and mice, with precisely the same results. The animals were sometimes left in the air, at other times buried, and generally in a moist place. In every instance putrefaction made more or less progress at first; but in a few days a peculiar garlicky odour arose, from which time the progress of decay seemed to be arrested; and the bodies underwent a process of hardening and desiccation which completely preserved them.[^[800]]

On considering attentively the illustrations now given, the toxicologist can hardly doubt that in some cases arsenic has appeared both to retard and to modify putrefaction in the bodies of persons poisoned with it.

Assuming arsenic to have been the cause of the preservation of the bodies, it becomes a point of consequence to account for its effect, and more particularly to reconcile that effect with what has certainly been noticed in other cases of poisoning with the same substance, namely, ordinary rapidity of decay, if not actually an increased tendency to putrefaction.

At the outset of this part of the inquiry some light may be thrown upon it by separating the local from the general operation of arsenic.

Arsenic is a good preservative of animal textures when it is directly applied to them in sufficient quantity. This is well known to stuffers of birds and beasts, was experimentally ascertained by Guyton Morveau,[^[801]] and has come also under my observation.[^[802]] It is now likewise known to be an excellent substance for preserving bodies, when injected in the form of solution into the blood-vessels.

Hence, if in a case of poisoning the arsenic be not discharged by vomiting, and the patient die soon, it will act as an antiseptic on the stomach at least, perhaps on the intestines also; while the rest of the body may decay in the usual manner. This is very well shown in a case examined by Dr. Borges, medical inspector at Minden, fourteen weeks after death. The stomach and intestines were firm, of a grayish-white colour, and contained crumbs of bread, while all the other organs in the belly were pulpy, and the external parts adipocirous.[^[803]] It is also equally well exemplified in a case that happened at Chemnitz so early as 1726, and which was examined five weeks after burial. The skin was every where very putrid, but the stomach and intestines were perfectly fresh.[^[804]] In the case of Warden the appearances were precisely the same. Three weeks after burial the Dundee inspectors found the external parts much decayed, yet three weeks later the stomach and intestines were found by myself in a state of almost perfect preservation. A striking experiment performed by Dr. Borges on a rabbit will likewise illustrate clearly the fact now under consideration. The rabbit was killed in less than a day with ten grains of arsenic, and its body was buried for thirteen months in a moist place under the eaves of a house. At the end of this period it was found, that “the skin, muscles, cellular tissue, ligaments and all the viscera, except the alimentary canal, had disappeared, without leaving a trace; but the alimentary canal from the throat to the anus, along with the hair and the bare bones, was quite entire.”[^[805]]

In all of these cases arsenic was found in the body. In the rabbit experimented on by Dr. Borges, above five grains of arsenic were separated in the form of a metallic sublimate.

But, on the contrary, if the arsenic is all or nearly all discharged by vomiting, not only the body generally, but likewise even the stomach and intestines, may follow the usual course of decay. Accordingly, in the case of the child formerly quoted ([273]), where the body putrified in the usual manner, only four grains and a half of arsenic had been taken; and as it was swallowed in a state of solution and caused violent vomiting, it must have been almost all ejected. Nay, in such circumstances, the alimentary canal, in consequence of its unnatural supply of moisture and incipient disorganization, may decay somewhat faster than other parts. Thus Dr. Murray observed in the case of a man formerly mentioned ([264]), who lived under violent gastritic symptoms for seven days, and vomited much, that the stomach, which was removed for more minute examination, decayed so rapidly that in twenty-four hours an examination was impracticable, while the body in general rather resisted putrefaction.[^[806]]

The preceding statements on the differences in the state of preservation of the body after poisoning with arsenic are not then incapable of some explanation. Nevertheless, it must be granted that the reasons assigned will not account for all the apparent cases of the preservative powers of arsenic. And especially they will not explain how the whole body has sometimes resisted decay altogether, and become as it were mummified. It is impossible to ascribe this preservation to the spelling power of the arsenic diffused throughout the body in the blood; the quantity there being extremely small. Consequently if the preservation of the bodies is not occasioned by some accidental collateral cause (a mode of accounting for the phenomena which seems inadmissible), this property of arsenic must depend on its causing, by some operation on the living body, a different disposition and affinity among the ultimate elements of organized matter, and so altering the operation of physical laws on it. There appears no sound reason for rejecting this supposition, especially as it is necessary to admit an analogous change of affinities as the only mode of accounting for a still more incomprehensible violation of the ordinary laws of nature,—the spontaneous combustion, or preternatural combustibility, of the human body.

The following judicious observations by Harles on this subject are worthy of attention:—“In regard,” says he, “to this singular property of arsenic, now no longer doubtful, it should be remembered that certain circumstances will limit or impair it, while others will favour or increase it;—circumstances, for example, connected with the soil of the burying-ground, or the air of the vaults where the bodies are deposited. Different soils and different conditions of the air will materially affect the decomposition of all bodies indiscriminately, and will therefore affect likewise the antiseptic properties of arsenic. For it would be absurd to ascribe to arsenic the power of preventing putrefaction in all circumstances whatsoever,—a power which those who make use of it for preserving skins know very well it does not possess, and a power possessed by no antiseptic whatever, not even by alcohol.”[^[807]]

An important consequence of the preservative tendency of arsenic is, that in many instances the body in this kind of poisoning may be found long after death in so perfect a state as to admit of an accurate medico-legal inspection and a successful chemical analysis. In one of his cases Dr. Bachmann detected arsenic in the stomach fourteen months after interment; Dr. Borges had no difficulty in detecting it in an animal after thirteen months; Mr. Herapath discovered it after fourteen months in the human body; M. Henry detected it after three years and a half, and obtained no less than seven grains of metallic arsenic from the shrivelled viscera;[^[808]] and MM. Ozanam and Idt found it after the long interval of seven years.—The late experiments of Orfila and Lesueur confirm the fact that arsenic may remain long in contact with decaying animal matter, and yet continue in such a state as to be easily detected.[^[809]] It might be supposed that the poison would pass off partly in the gaseous state by being converted into arseniuretted-hydrogen, partly in the liquid state by becoming arsenite of ammonia, a very soluble compound. But the fact nevertheless is, that, notwithstanding these reasons for its disappearance, it may be detected after the lapse of several years.

Under the head of the diseased appearances left by arsenic in the dead body, every change of structure has now been described which has been mentioned by authors and supported by trustworthy statements. Another set of appearances may still be noticed; but they are here separated from the rest, because the author who first notices them has not been supported in the statement by any special observations of his own, or by an adequate number of facts observed by others. In an elaborate essay on a case of poisoning by Professor Seiler of Wittemberg, it is said in general terms that arsenic may cause gorging of the vessels of the brain, effusion of serum into the ventricles, inflammation of the brain, and even extravasation of blood.[^[810]] Turgescence of vessels is mentioned in several published cases, and I have myself met with it. But it is seldom so considerable as to attract attention. In the following instance, however, which has been related by Dr. Hofer of Biberach the evidence of cerebral congestion was unequivocal. A man addicted to intoxication, but enjoying good health otherwise, was attacked after supper with sickness, vomiting, and pain in the belly. On going to bed he fell soon quiet; and six hours after he took ill, he was found dead. Arsenic was detected in the stomach, and in what he vomited; and considerable redness was seen on the villous coat of the stomach. But the most remarkable appearances were gorging of the cerebral vessels, adhesion of the dura mater to the membranes beneath, and the effusion of eight ounces of serosity into the lateral ventricles.[^[811]] The only instance I am acquainted with to justify the opinion that extravasation of blood into the brain may occur from poisoning with arsenic, is the remarkable case of apparent death from eating poultry poisoned with arsenic, which was communicated to me by Mr. Jamieson of Aberdeen. The individual, after suffering under the usual primary symptoms, became apoplectic after a fit of sneezing, and died three days afterwards; and in the dead body, besides other signs of disease in the brain, a recent clot of blood was found in the right anterior lobe. (See p. [69].)

It is quite unnecessary to notice lividity of the skin among the signs of poisoning with arsenic, except for the mere purpose of reminding the medical jurist that, although it has been sometimes much relied on as a sign of death from arsenic, it is not of the slightest importance as a sign either of that or of any other kind of poisoning. (See p. [51].)

The action of arsenic on the alimentary canal after death will now require a few remarks; the purpose of which is to prepare the medical inspector for investigating attempts to impute the crime of poisoning to innocent persons, by introducing arsenic into the dead body. Such attempts, according to Orfila, have been made; but I am not acquainted with any actual instance.

The action of arsenic on dead intestine has been fully examined by the last mentioned author. If it is introduced into the anus immediately after death, and allowed to remain there twenty-four hours, the mucous membrane in contact with it becomes of a lively red colour, with darker interspersed patches as if from extravasation. The other coats are natural; and so is the mucous membrane itself wherever the poison does not actually touch it. Consequently the margin of the coloration is abrupt and well defined. When the arsenic is not introduced till twenty-four hours after death, the part to which it is actually applied presents dark patches, while the rest of the membrane is quite healthy.[^[812]]

The appearance of redness in the former case is probably the result of lingering vitality. The cause of the dark appearance in the latter it is not easy to comprehend.

When arsenic has been applied, during life, the redness, if it has had time to begin at all, extends to some distance from the points with which the poison has been in contact, and passes by degrees into the healthy colour of the surrounding membrane.

On reviewing what has been said of the pathological appearances caused by arsenic, it must appear that the medical jurist can never be supplied from this source alone with satisfactory evidence of the cause of death. But in some circumstances the evidence may amount to a strong probability of one variety or another of irritant poisoning. Mere redness, conjoined or not with softening of the mucous membrane, may justify suspicion only. But if there should be found in the body of a person who has died of a few days’ illness, redness, black warty extravasation, and circumscribed ulcers of the villous coat of the stomach,—effusion of blood or bloody clots among the contents of that organ,—also redness of the intestines, more especially redness and ulceration of the colon and rectum,—and redness of the pharynx, or of this along with the gullet,—the proof of poisoning with some irritant will amount to a strong presumption. At least it is difficult to mention any natural disease which could produce in so short a time such a conjunction of appearances as this; which arsenic and other analogous poisons sometimes occasion.

Section IV.—On the Treatment of Poisoning with Arsenic.

It was formerly proved that arsenic acts in all its forms of chemical combination, which have been hitherto tried, and nearly in the ratio of their solubility. This general fact is conformable with the law laid down as to the influence of chemical changes on the energy of poisons which enter the blood [p. [37]]. Hence every supposed chemical antidote must be useless, which does not render the arsenic insoluble not only in water, but likewise in the contents and secretions of the stomach.

The antidotes chiefly trusted to until recent times, such as vinegar, sugar, butter and other oily substances, lime-water, bitter decoctions, and the like, have now justly fallen into disuse. The liver of sulphur or sulphuret of potassium, which maintained its character for some time longer on account of its chemical action with oxide of arsenic in solution, is not more efficacious. The experiments of Renault on the counter-poisons for arsenic, confirmed by the subsequent researches of Orfila, have proved that the arsenical sulphuret formed by solutions of the liver of sulphur is scarcely less active than the oxide itself.[^[813]]

It appears that fine impalpable powders, though inert as physiological agents, and destitute of any true chemical action with oxide of arsenic, may nevertheless prove useful in certain limited circumstances. Thus Mr. Hume of London and others have apparently found some advantage in the administration of large doses of magnesia.[^[814]] If this substance be of any use at all, which is doubtful, it can act only by covering the arsenical particles with its fine insoluble powder, and so preventing them from coming in contact with the surface of the stomach; for in its state of magnesia it has no chemical action with oxide of arsenic. Another remedy of the same nature is charcoal powder, which was proposed in 1813 with much confidence by M. Bertrand.[^[815]] That it has some efficacy when swallowed along with the poison seems to admit of no doubt; for the proposer of it himself swallowed five grains of arsenic in one dose along with charcoal in a state of emulsion, and sustained little inconvenience of any kind. In all probability it acts merely by enveloping the particles of arsenic. But it may possibly be also of service, if recently exposed to heat, by the superficial attraction it exerts over substances in solution; through means of which property it will remove many soluble substances from a fluid, and render them insoluble. Charcoal, however, has been proved to be destitute of all efficacy when not administered till after the arsenic is swallowed. The one must be given along with the other, otherwise it is useless.[^[816]]

For some time past the formation of an insoluble arsenite has been aimed at by most experimentalists who have endeavoured to discover an antidote for arsenic. But in general the arsenites, though very insoluble in water, are sufficiently so in weak acids or in organic fluids, so that they are soluble enough in the juices of the stomach to enter the blood in such quantity as to prove fatal. The only exception now admitted to exist is the arsenite produced when a solution of oxide of arsenic is brought in contact with the hydrated sesquioxide of iron. The compound thus formed is held to be insoluble in the secretions of the stomach; and consequently the hydrated sesquioxide of iron is usually regarded as a true antidote.

The substance, the Ferrugo of the Edinburgh Pharmacopœia,—a compound which differs little from the older preparation, the rust of iron, when not deprived of its combined water,—was announced in 1834 by Drs. Bunsen and Berthold as an effectual remedy even when given some time after the arsenic is swallowed.[^[817]] Their experiments were repeated with variable success. Similar results were obtained by MM. Soubeiran and Miquel, as well as MM. Orfila and Lesueur, in some experiments on dogs, and by M. Boullay on the horse.[^[818]] The last experimentalist found that the effects of a dose adequate ta occasion death are almost entirely prevented in the horse by giving the oxide of iron either immediately after the poison, or within four hours. Results of the same nature were obtained in this country by Mr. Donald Mackenzie.[^[819]] Others, however, such as Mr. Brett[^[820]] and Mr. Orton,[^[821]] have failed to observe any antidotal virtues, and even deny that the sesquioxide of iron can remove oxide of arsenic from a state of solution. But in 1840 the causes of these discrepant statements were explained by Dr. Douglas Maclagan,[^[822]] who found, in corroboration of the remarks of Drs. Bunsen and Berthold, as well as various French authorities, that the oxide must be given in large quantity, and that the failures of some were owing to the quantity used having been too small. He ascertained, that, in order to remove one part of arsenic from a state of solution, twelve parts of oxide of iron in the moist state are necessary, and sixty parts if it be previously dried; that the arsenic so appropriated is with difficulty removed from the insoluble matter even by boiling; and that, as the discoverers of this antidote first stated, the preparation made by precipitating the sesquioxide of iron by means of ammonia, is a more active form than any other. As the oxide prepared in this way always contains ammonia, and the proportion necessary for removing the arsenic is far greater than what is required to constitute a simple arsenite of iron, it is reasonable to infer that the ammonia forms a part of the insoluble compound actually produced. At all events the action of the antidote would appear to be chemical, and not mechanical, as has been thought by many, and as was stated to be probable in the last edition of this work. In confirmation of these views, and as a fact worthy of farther investigation on its own account, it is worthy of notice, that, according to Dr. Duflos, the acetate of sesquioxide of iron answers equally well as an antidote with the sesquioxide itself. It precipitates both arsenious and arsenic acid from every state of solution, and always the more quickly the more the solution is diluted; and the co-existence of acetic acid is no obstacle to this action taking place.[^[823]]—More recently Professor Orfila has called in question the absolute efficacy generally ascribed to the sesquioxide of iron. He alleges that the arsenical compound formed, though insoluble in water, is soluble to some extent in the gastric juices, and is consequently a poison to animals; that the sesquioxide is therefore only partial in its operation as a remedy; but yet that the influence of the animal fluids in the stomach in counteracting it may be overcome by giving it in excess, so that, as fast as the compound is dissolved, it is thrown down again.[^[824]]

The cases of the successful employment of this antidote in the human subject, which have appeared in the periodical press during the last eight years, are so numerous, that its utility can scarcely be called in question, whatsoever may be its precise mode of action. The hydrated sesquioxide of iron ought therefore to be kept in readiness in every druggist’s establishment; for it cannot be prepared when wanted without great loss of time. The quickest way to make it is to dissolve the common anhydrous sesquioxide, formerly miscalled carbonate of iron, in diluted sulphuric acid aided with a gentle heat; to decompose the hot solution with an excess of strong ammonia; to filter off the fluid by means of a cloth filter and wash the precipitate well with warm water; and then to let it drain thoroughly and to squeeze out more of the water by expression. It should be kept in this state, and not allowed to dry.

In regard to all antidotes for arsenic, it must be observed, that they can seldom be otherwise employed than in unfavourable circumstances. If, as most generally happens, the poison has been taken some time before medical aid is obtained, its powder is diffused over the surface of the stomach, adheres with tenacity to the villous coat, and excites the secretion of tough mucus, through which it is with difficulty reached by any antidote possessing a chemical action with it. In all cases, therefore, it is advisable to promote vomiting occasionally, if not already full and free, so as to aid the stomach in clearing itself of the secreted mucus.

If the existence of a chemical antidote for arsenic be doubtful, much less is there any one known of that rarer denomination which operates by exciting in the system an action contrary to that established by the poison.

A good deal, however, may be done by general medical treatment to improve the chance of recovery. If vomiting should be delayed, as often happens, for half an hour or more, advantage ought to be taken of the opportunity to administer an emetic of the sulphate of zinc, with the view of withdrawing the powder in mass before it is diffused over the stomach; and for the same purpose milk should be drunk both before and after vomiting has begun, as it appears to be the best substance for enveloping the powder, and so procuring its discharge. The patient should never be allowed to exhaust his strength in retching without a little milk or other fluid in his stomach to act on. At the same time, there is probably some justice in the opinion expressed by a late writer on this subject, that large draughts of diluents are injurious; and that, unless the stomach is allowed to contract fully and frequently on itself, it cannot discharge from its surface the mucous secretion, in which the powder of arsenic is in general closely enveloped.[^[825]] The stomach-pump, although it has been applied to cases of poisoning with arsenic, does not possess any advantage whatever over emetics or the natural efforts of nature, and is less effectual in expelling the mucus which envelopes the poison. Even emetics are unnecessary, when full vomiting is caused by the poison itself. If milk in sufficient quantity cannot be procured, strong farinaceous decoctions will probably prove useful.

Supposing the poison to have been removed from the stomach, or that the patient has been put on the course which appears best fitted to accomplish that end,—two objects remain to be accomplished, namely, to allay the inflammation of the alimentary canal, and to support the system under that extraordinary depression which it undergoes in the generality of cases. Were it not for the latter of these objects, the treatment would be both obvious and frequently successful. But it is highly probable that the active remedies, to which the physician trusts in internal inflammations generally, and which are urgently called for by the inflammation caused by arsenic, cannot be enforced with the requisite vigour, on account of the remote depressing effects also produced by this poison on the body.

Nevertheless, it is certain that in a few even very aggravated cases the purest and most vigorous antiphlogistic treatment has been resorted to with success. Dr. Roget’s patient, whose case was formerly referred to for another purpose, seems to have been saved by venesection; and at all events, the amelioration effected was unequivocal. In the Medical Repository there is another good example of the beneficial effects of blood-letting carried even to a greater extent than in Roget’s case;[^[826]] and in the Medical and Physical Journal[^[827]] a third instance will be found, which after the first twenty-four hours assumed the form of pure gastritis, and was treated as such with success. Blood-letting ought not to be practised till the poison is nearly all discharged from the stomach, because it promotes absorption by causing emptiness of the blood-vessels.

Orfila has lately advocated the use of blood-letting, on the ground that it tends to remove from the system a portion of the poison which circulates with the blood, and is the main source of danger to life. He has endeavoured to show by experiments on animals, that doses adequate to cause death may be given without this result following, if depletion be vigorously enforced along with other treatment. And he has related a case of recovery in the human subject under unfavourable circumstances, where blood-letting was practised five times, and on every occasion with marked relief.[^[828]]

It is not probable that any material advantage will be derived from topical blood-letting, at least in the early stage, because if depletion is to be of use at all, it must be carried at once to a far greater extent than it is possible to attain by local evacuants. Blisters on the abdomen will prove useful auxiliaries in the advanced stage.

While many have advocated the employment of blood-letting and other antiphlogistics, and have used them with apparent advantage, Rasori was of opinion, and more recently Giacomini has strenuously maintained that the proper treatment in all cases of arsenical poisoning is the purely stimulant method. The remedy recommended by the latter is a mixture of eight ounces of beef-tea and two ounces of wine. These notions are evidently dictated by the prevailing pathological delusions of the Italian school. Although upheld in some measure by a Report of the Parisian Academy of Medicine upon some experiments by M. Rognetta on this subject,[^[829]] Professor Orfila subsequently proved, that the practice recommended is utterly useless, if not even hurtful.[^[830]] At the same time no one who has ever seen a case of poisoning by arsenic can doubt that it is often necessary to counteract the overwhelming languor of the circulation by the moderate use of stimulants.

Opium in repeated doses will prove useful, when the poison has been removed, and the inflammation subdued by blood-letting. And I conceive that to the form of gastritis, caused by arsenic, may be applied a method of treatment by anodynes, which has been successfully used in acute inflammation generally,—the free administration of opium immediately after copious depletion. For the safe employment of this method, however, it is essential that the arsenic be completely removed from the stomach and intestines. And from the results of many cases there must always be great reason to apprehend, that, before the treatment can be with propriety resorted to, the patient’s strength will be exhausted.

The harassing fits of vomiting which often continue long after the poison has been discharged from the stomach are best removed by opium in the form of clyster, or rubbed over the inside of the rectum in the form of ointment with the finger.

The use of laxatives is particularly required in all cases in which there is tenesmus instead of diarrhœa, or where, in the latter stages, diarrhœa is succeeded by constipation; and castor oil is the laxative generally preferred. While diarrhœa is present, and the evacuations are profuse or the intestines have been thoroughly emptied, laxatives are unnecessary or even hurtful; but emollient clysters are advisable, and opium in the form of enema or suppository. In short, so far as regards the intestinal affection, the treatment of the acute stage of dysentery is to be enforced.

Professor Orfila lays great stress on the employment of diuretics after the stomach has been cleared out, and founds this practice on his observations which show that arsenic is absorbed into the blood, and gradually discharged by the secretions, especially the urine. Experience seems to confirm theory. Dogs, after receiving a small dose, adequate to occasion death, recovered under the active administration of diuretics. Having ascertained that this animal was constantly killed in a period varying from thirty to forty-eight hours by two grains applied to a wound, provided no remedies were employed, he tried the diuretic method with six which had been thus poisoned; and all of them recovered.[^[831]] The diuretic he recommends is a mixture of ten pounds of water, five of white [French] wine, a bottle of Selzer water, and three ounces of nitre; the dose of which is two wine-glassfuls frequently.[^[832]] This method has been followed with success in the human subject. M. Augouard relates a case where 230 grains produced in half an hour all the usual symptoms, which he immediately proceeded to treat by administering a grain and a half of tartar-emetic, to excite full vomiting. Having accomplished this object, he gave frequent doses of decoction of mallow “strongly salpetred,” which in seven hours excited so profuse a diuresis that in the ensuing ten hours no less than eighteen imperial pints was discharged. At the close of this period a material amendment took place, and recovery was complete in fifteen days.[^[833]] It may be observed, however, that it is sometimes impossible to excite diuresis.[^[834]]

Little need be said of the practice to be pursued in the advanced stages of poisoning with arsenic, when convalescence has begun. The principal object is to support the system by mild nourishment, avoiding at the same time stimulant diet of every kind, but especially spirituous and vinous liquors. Whatever may be the difference of results obtained with the antiphlogistic mode of cure, the opposite system has been invariably detrimental in the advanced stage.

The treatment of the nervous and dyspeptic affections, which may supervene after the symptoms of local inflammation have ceased, is not a fit object of review in this work, as it would lead to great details.

CHAPTER XIV.
OF POISONING WITH MERCURY.

The next genus of the metallic poisons includes the preparations of mercury. Some of these are hardly less important than the arsenical compounds. They act with equal energy, produce the same violent symptoms, and cause death with the same rapidity. They have therefore been often given with a criminal intent; and have thus become the subject of inquiry upon trials. In another respect, too, they claim the regard of the medical jurist: their effects on the body, when insidiously introduced in the practice of the arts in which mercury is used, form a branch of that department of medical police, which treats of the influence of trades on the health.

Section I.—Of the Chemical History and Tests for the preparations of Mercury.

Mercury is a fluid metal, exceedingly brilliant, of a silver-white colour, and of the specific gravity 13·568.

When heated to about 660° F. it sublimes, and on cooling it condenses unchanged. If this experiment is made in a small glass tube, the metal forms a white ring of brilliant globules, which may be made to coalesce into a single large one. In this way its physical properties may be recognised, though the quantity is exceedingly minute.

Two oxides of this metal, a protoxide and peroxide, exist in combination with acids. A bluish-gray or grayish-black protoxide is separated from the salts of the protoxide by the fixed alkalis. The peroxide has an orange-red colour, and is the common red precipitate of the apothecary. Mercury unites with sulphur in two proportions. The proto-sulphuret, which is black, is formed from the salts of the protoxide by the action of sulphuretted-hydrogen: the bisulphuret is the well known pigment, cinnabar or vermilion. Mercury likewise unites with chlorine in two proportions, forming an insoluble protochloride and a soluble bichloride, the former calomel, the latter corrosive sublimate. It likewise unites with cyanogen. Mercury also unites in the state of protoxide and peroxide with the acids. Several compound salts are known to the chemist, but few occur in commerce or the arts.

Among the compounds resulting from the action of this metal with other substances, those which require notice in a toxicological treatise are the following:—1. The binoxide or red precipitate; 2. The bisulphuret or vermilion; 3. The protochloride or calomel; 4. The bichloride or corrosive sublimate; 5. The sulphate or Turbith mineral; 6. The bicyanide or prussiate of mercury; and 7. The nitrates of mercury. Its other compounds are of little consequence to the toxicologist.

1. Of Red Precipitate.

Red precipitate, when well prepared, is in the form of fine powder or small, brilliant, heavy scales of a scarlet or orange colour. It consists of 101 mercury and 8 oxygen. It is insoluble in water.

It is easily distinguished from all other substances by the action of heat. If a little of it is heated in a small glass tube, it becomes dark brown, and on cooling recovers its original colour. But if the heat be raised higher, metallic globules are sublimed, and oxygen gas is disengaged. The escape of oxygen may be ascertained by plunging to the bottom a small bit of burning wood, when the combustion will be observed to be enlivened.

2. Of Cinnabar.

Cinnabar or vermilion, the bisulphuret of mercury, usually exists in the arts in the form of a fine, heavy, red powder, of a peculiar tint, which is termed from this substance vermilion-red. In mass its structure is coarsely-fibrous, and its colour reddish-brown; and it has some lustre. When thrown down from a solution of corrosive sublimate by sulphuretted-hydrogen, or the alkaline hydrosulphates, it forms a black powder, which acquires a red tint by being sublimed. It is composed of 101 metal and 16 sulphur.

It is distinguished from other substances by the operation of heat, and by the effects of reduction with iron filings. Heated alone in a tube it sublimes without change. Its colour, indeed, which is fugacious under heat unless particular manipulations are used, becomes darker and dingy; but its lustre and crystalline texture are retained. Heated with iron filings in a tube, it gives off globules of mercury; and the existence of sulphuret of iron in what remains may be proved by the escape of sulphuretted-hydrogen on the addition of diluted sulphuric acid.

3. Of Turbith Mineral.

The Turbith mineral, or subsulphate of the binoxide of mercury, exists in the form of a bright lemon-yellow, heavy powder. It is soluble in 2000 parts of water, and has an acrid taste.

It may be known by the effects of heat. When heated in a tube, globules of mercury are sublimed, and at the same time sulphurous acid gas is disengaged, as may be ascertained by the smell. But a better method of proving the existence of sulphuric acid in it is to expose it to the action of a solution of caustic potass: The potass separates from it the brownish-yellow peroxide, and appropriates the sulphuric acid, which may be found in the solution by acidulating with nitric acid, and then adding hydrochlorate of baryta, when a heavy, snow-white precipitate of sulphate of baryta will form. The nitric acid used in this process must be quite pure, and free of sulphuric acid, which the acid of commerce often contains.

4. Of Calomel.

Calomel (muriate, mild muriate, chloride, protochloride of mercury), is commonly met with in the shops in the form of a heavy powder, having a faint yellowish-white colour, and no taste or smell. In mass it forms compact, fibrous, translucent, shining cakes of great density. It is insoluble in water.

It is distinguished by the effects of heat, and those of the solution of caustic potass. Heated in a tube it sublimes unchanged, and condenses in a crystalline or crumbly mass. The solution of caustic potass or soda turns it at once black, disengaging protoxide of mercury and acquiring hydrochloric acid, the presence of which is proved by neutralizing the solution with nitric acid, and adding nitrate of silver, when a heavy white precipitate is formed, the chloride of silver. In applying this process, care must be taken to employ potass quite free of muriates, and nitric acid free of muriatic acid. Ammonia also renders calomel powder black, but the action and product are much more complex in their nature.

5. Of Corrosive Sublimate.

Corrosive sublimate (oxymuriate, corrosive muriate, bichloride of mercury), is by far the most important of the mercurial poisons, as it is both the most active of them, and the one most frequently used for criminal purposes. It is commonly met with in the form of a heavy, snow-white powder, or of small, broken crystals, or in white, compact, concave, crystalline cakes. It is permanent in the air; but in the sunshine is slowly decomposed, a gray insoluble powder being formed. It readily crystallizes, and the common form of the crystals is the quadrangular prism. Its specific gravity is 5·2. Its taste is strongly styptic, metallic, acrid, and persistent; and its dust powerfully irritates the nostrils. It is soluble, according to Thenard, in 20, according to Orfila, in 11 parts of temperate water, and in thrice its weight of boiling water. Its solution faintly reddens litmus. It is more soluble in alcohol than in water, boiling alcohol dissolving its own weight, and retaining when it cools, a fourth part. It is also very soluble in ether, so that ether will remove it from its aqueous solution. Corrosive sublimate may become the subject of a medico-legal analysis in three states. It may be in the solid form; it may be dissolved in water along with other mineral substances; and it may be mixed with vegetable and animal fluids or solids.

Of the Tests for Corrosive Sublimate in the solid state.

Corrosive sublimate in the solid state is distinguished from other substances by the action of the heat, and the effects of solution of caustic potass. Subjected to heat alone it sublimes in white acrid fumes; and if the experiment is made in a little tube, it condenses again unaltered in a crystalline cake. Treated with solution of caustic potass, it becomes yellow, the binoxide being disengaged, and hydrochloric acid uniting with the potass, as may be proved by nitrate of silver, after filtration and neutralization with nitric acid. The yellow colour of the binoxide which is separated in this process distinguishes corrosive sublimate from calomel, which is also decomposed by the potass solution, but yields a black protoxide. Caustic soda has the same effect. Not so caustic ammonia: Ammonia blackens calomel, but does not change the colour of corrosive sublimate, as it forms with it a white triple salt, commonly called white precipitate.

The process here described is the best and simplest method of determining chemically the nature of corrosive sublimate in its solid state. But two other tests may also be mentioned, as they have been a good deal used. A very good test is the process of reduction with potass, by which globules of mercury are sublimed, and a chloride of potassium left in the flux, as may be proved by the action of nitrate of silver on the solution of the flux previously neutralized with nitric acid. This test alone will not distinguish corrosive sublimate from calomel: The solubility of the former must be taken into account.—Another satisfactory test is the solution of protochloride of tin. Corrosive sublimate, when left for some time in this solution, first becomes grayish-black, and ere long its place is supplied by globules of mercury,—the chlorine being entirely abstracted by the protochloride of tin, which consequently passes to the state of a bichloride. Calomel is similarly affected.

Of the Tests for Corrosive Sublimate in a state of Solution.

Two processes may be mentioned for the detection of corrosive sublimate in mineral solutions,—a process by reduction, and a process by liquid tests.

Reduction process.—In order to procure mercury in its characteristic metallic state from a solution of corrosive sublimate, the following plan of procedure will be found the most delicate and convenient. Add to the solution, previously acidulated with hydrochloric acid if very weak, a little of the protochloride of tin, which will be seen presently to be a liquid reagent of great delicacy. If the solution is not darkened there is not present an appreciable quantity of mercury. If mercury is present a bluish-gray or grayish-black precipitate falls down, owing to the chemical action already particularized. After ebullition, this precipitate is to be allowed to subside, first in a tall glass vessel suited to the quantity of the solution, and afterwards in the small glass tube, Fig. 7, the superincumbent fluid being previously decanted off as far as possible. After it has subsided in the tube, the remaining fluid is withdrawn with the pipette, Fig. 8; water is poured over it; and this is withdrawn again after the precipitate has subsided a third time. The bottom of the tube is then cut off with a file, and the moisture which remains is driven off with a gentle heat. When this is accomplished, the powder, which is nothing else than metallic mercury, sometimes runs into globules. Should it not do so, the bit of tube is to be broken in pieces and heated in the tube, Fig. 1, when a brilliant ring of fine globules will be formed. If the globules are too minute to be visible to the naked eye, the tube is to be cut off with the file close to the ring; and the globules may then be easily made to coalesce into one or more of visible magnitude by scraping the inside of the tube with the point of a penknife.

This process is not recommended as preferable to the plan by liquid reagents which is next to be mentioned, and which is both more easily put in practice, and at the same time quite as satisfactory. It is related chiefly because it forms the ground-work of a process for detecting mercury in mixed animal or vegetable fluids. It will be remarked that the process does not prove with what acid the mercury was combined in the solution. But this is a defect of little consequence; for the only other soluble salts of mercury ever met with in the arts, namely, the nitrate, acetate, and cyanide, are too rare to be the source of any material fallacy; and are besides all equally poisonous with corrosive sublimate.

Process by Liquid Tests.—The process by liquid reagents consists in the application of several tests to separate portions of the solution. The tests which appear to me the most satisfactory are hydrosulphuric acid gas, hydriodate of potass, protochloride of tin, and nitrate of silver.

1. Hydrosulphuric acid gas transmitted in a stream through a solution of corrosive sublimate causes a dark, brownish-black precipitate, the bisulphuret of mercury. When the solution is not very diluted, the gas forms a whitish or yellowish precipitate before the blackening commences,—an effect which, according to Pfaff, distinguishes the salts of the peroxide of mercury from all other metals that are thrown down black from their solutions by sulphuretted-hydrogen.[^[835]] The cause of this is that the particles of sulphuret first formed acquire a thin covering of corrosive sublimate by that property which chemists of late have termed superficial attraction. Hydrosulphuric acid is a very delicate test of the presence of mercury. It will detect corrosive sublimate, where its proportion is only a 35000th of the solution.[^[836]]

This test is not alone sufficient, unless reliance be placed on Pfaff’s criterion, which is rather a trivial one; for hydrosulphuric acid occasions a black precipitate in other metallic solutions, for example, in solutions of lead, copper, bismuth and silver. In mixed organic fluids its action is not liable to be prevented; but the precipitate formed is often kept intimately suspended, as in the instance of milk. It may be conveniently used in the form of hydrosulphate of ammonia. This test produces a dark-brown precipitate, which is said to pass slowly to a bright cinnabar red; but I have not been able to observe any transformation of the kind.

Hydriodate of Potass causes in solutions of corrosive sublimate a beautiful pale scarlet precipitate, which rapidly deepens in tint. The precipitate is the biniodide of mercury. This is a test of great delicacy when skilfully used, as it acts where the salt forms only a 7000th of the solution (Devergie). Care must be taken, however, not to add too much of the test, because the precipitate is soluble in an excess of the hydriodate, or too little, because the precipitate is also soluble in a considerable excess of corrosive sublimate.

The action of hydriodate of potass is not liable to any important ambiguity: no other iodide resembles in colour the biniodide of mercury. It is not a certain test, however, when other salts exist in solution along with corrosive sublimate. Chloride of sodium, nitrate of potass, and probably also other neutral salts possess the power of dissolving the precipitate. Sulphuric and nitric acids, even considerably diluted, oxidate and dissolve the mercury, and disengage iodine, which colours the fluid reddish-brown. When corrosive sublimate is dissolved in coloured vegetable infusions or animal fluids, the hydriodate of potass cannot be relied on, the colour of the precipitate being altered, as in infusion of galls, or the action of the test being suspended altogether, as by milk.

Protochloride of Tin causes first a white precipitate, which, when more of the test is added, gives place to a grayish-black one. In very diluted solutions the colour struck is grayish or grayish-black from the beginning. In such solutions Devergie has found it useful to acidulate with hydrochloric acid before adding the test. The chemical action here is peculiar. The white powder thrown down at first is protochloride of mercury; a part of the chlorine of the bichloride of mercury having been abstracted by the protochloride of tin, which becomes in consequence the bichloride. On more of the test being added these changes are repeated, the chlorine is removed from the protochloride of mercury, and metallic mercury falls down. This test is one of extreme delicacy, affecting solutions which contain only an 80,000th of salt. It is prepared by acting on tin powder or tinfoil with strong hydrochloric acid aided by a gentle heat. The solution must be kept carefully excluded from the air; otherwise bichloride of tin is formed, which does not act at all on the solution of corrosive sublimate.

The protochloride of tin is not liable to any fallacy. Neither is it liable to be suspended in its action by the co-existence of other saline substances. It causes precipitates with almost all animal and most vegetable fluids. But when corrosive sublimate is present, even in very small proportion, the precipitate is always darker than when no mercurial salt exists in solution, and frequently has its proper grayish-black tint. This property, as will presently be seen, is the foundation of a process for the detection of mercury in all states of admixture with organic matters.

Nitrate of Silver causes a heavy white precipitate, the chloride of silver, which darkens under exposure to light. This is a test for the chlorine of the corrosive sublimate, but not for the mercury, and is a necessary addition to the three former tests in order to determine how the mercury is kept in solution. It acts with very great delicacy.

It is of no use, however, when chlorine or hydrochloric acid is present either free or combined with other bases. It is not of use, therefore, in animal fluids and vegetable infusions, because very many of them, besides organic principles which form white precipitates with this test, contain a sensible proportion of hydrochlorate of soda.

Although the preceding liquid reagents when employed conjunctly are amply sufficient for determining the presence of corrosive sublimate in a fluid, many other tests hardly less characteristic and delicate have been used by medical jurists. These will now be shortly mentioned.

1. Lime-Water throws down the binoxide of mercury in the form of a heavy yellow powder. The precipitate first thrown down is lemon-yellow, an additional quantity of the test gives it a reddish-yellow tint, and a still larger quantity restores the lemon-yellow. This test is characteristic, but not so delicate as those already mentioned.—2. Caustic Potass has precisely the same effect as lime-water, except that the tint of the precipitate is always yellow—3. Caustic Ammonia causes a fine, white, flocculent precipitate of intricate composition, commonly called precipitate. It is a very delicate test; but ammonia likewise causes a white precipitate in other metallic solutions.—4. Carbonate of Potass causes a brisk-red precipitate, by virtue of a double decomposition, the precipitate being carbonate of mercury.—5. The Ferro-cyanate of Potass causes at first a white precipitate, the ferro-cyanide of mercury. The precipitate becomes slowly yellowish, and at length pale-blue, owing, it is believed, to the admixture of a small quantity of iron with the corrosive sublimate.—6. A polished plate of Copper immersed in a solution of corrosive sublimate becomes in a few seconds tarnished and brownish; and in the course of half an hour a grayish-white powder is formed on its surface. This powder, according to Orfila,[^[837]] is a mixture of calomel, mercury, and a copper amalgam. If it is wiped off, and the plate then rubbed briskly where tarnished, it assumes a white argentine appearance.—7. A little Mercury put into a solution of corrosive sublimate is instantly tarnished on the surface; the solution in a few seconds becomes turbid, a heavy grayish precipitate is formed, and in no long time with the aid of agitation the whole corrosive sublimate is removed from the solution. The powdery precipitate is a mixture of finely divided mercury and calomel; the former being derived from the surface of the mercury, and the latter produced by the corrosive sublimate uniting with a larger proportion of the metal to form the protochloride.—8. A solution of Albumen causes a white precipitate, which is soluble in a considerable excess of the reagent. The nature of this precipitate will be discussed presently.—A slip of Gold aided by galvanism, becomes silver-white in the solution, in consequence of the formation of an amalgam. When the solution is concentrated, it may be thus tested by simply putting a few drops on a bit of gold, and touching the gold through the solution with an iron point, as recommended by Mr. Sylvester and Dr. Paris.[^[838]] When the solution is very weak, a different method is necessary, and a process for the purpose has been proposed by M. Devergie, which appears so delicate, accurate, and at the same time simple, a mode of detecting traces of mercury in very weak solutions, as to deserve detailed notice. A thin plate of gold, and another of tin, a few lines broad, and two or three inches long, being closely applied to one another by silk threads at the ends, and then twisted spirally, this galvanic pile is left for twenty-four or thirty-six hours in the solution previously acidulated with muriatic acid; upon which the gold is found whitened, and mercury may be obtained in globules by heating the gold in a tube. Distinct indications may be obtained by this method, where the corrosive sublimate forms but an 80,000th of the water.[^[839]] For facility of application, an important condition is, that the quantity of fluid should not exceed three or four ounces, because in a larger quantity the pile of the size stated above cannot remove the whole mercury. Somewhat similar to this is the galvanic method of Mr. Davy of Dublin. He proposes to place the suspected solution in a platinum crucible with hydrochloric acid, diluted with its own weight of water, to excite galvanic action by immersing in the fluid a plate of zinc, and to sublime and collect the reduced mercury, by washing the crucible, heating it over a spirit-lamp, and condensing the mercurial vapours on a plate of glass placed over the mouth of the crucible.[^[840]]

Of the Tests for Corrosive Sublimate when mixed with Organic Fluids and Solids.

The process for detecting corrosive sublimate in mixtures of organic fluids and solids, such as the contents of the stomach, is now to be described. But some remarks are previously required on the chemical relations subsisting between this poison and various principles of the vegetable and animal kingdoms.

These relations are important in a medico-legal point of view on several grounds. On the one hand, the chemical changes which corrosive sublimate undergoes often alter so much the action of its tests, as to render necessary a process of analysis materially different from any hitherto described. And on the other hand, these chemical changes, of which some take place rapidly, others slowly, will hinder the corrosive sublimate, more or less completely, from exerting its usual operation on the animal system; so that it may thus either accidentally fail to act as intended, or be checked in its operation by antidotes administered for the purpose.

It appears from the researches of M. Boullay, confirmed by those of Professor Orfila, that various vegetable fluids, extracts, fixed oils, volatile oils and resins, possess the power of decomposing corrosive sublimate. According to M. Boullay, a part of the chlorine is gradually disengaged in the form of hydrochloric acid, and the salt is consequently converted into calomel, which is deposited in a state of mixture or combination with vegetable matter.[^[841]] Some vegetable fluids produce this change at once, others not for some hours, others not for days, and only when aided by a temperature approaching ebullition. For example, a strong infusion of tea, mixed with a solution of a few grains of corrosive sublimate, becomes immediately muddy, and an insoluble cloud separates in half an hour. But the remaining fluid slowly becomes muddy again, and in eight days a considerable precipitate is formed. Both precipitates contain mercury; the former, I find, contains 31 per cent. On the other hand, an infusion of galls in like circumstances does not become muddy for six or seven hours. A solution of sugar does not undergo any change after being mixed with a solution of corrosive sublimate for months at the ordinary temperature of the atmosphere; but at the temperature of ebullition Boullay has found that the usual changes ensue, though to no great extent.

The experiments of Professor Taddei of Florence have farther shown, that the property of decomposing corrosive sublimate is possessed in an eminent degree by one of the vegetable solids, gluten. If the salt in solution is properly mixed with a due proportion of gluten of wheat, that is, about four times its weight, the water will be found no longer to contain any mercury, while the gluten becomes whitish, brittle, hard, and not prone to putrefaction. A ternary compound is formed, the protochloride of mercury and gluten.[^[842]] This change is effected with rapidity.

The researches of Berthollet,[^[843]] repeated and extended by Professor Orfila,[^[844]] have also shown that the same property is possessed by most animal fluids and solids. Among the soluble animal principles, albumen, caesin, osmazôme, and gelatin possess it in a high degree, but above all albumen, the action of which has been examined with some care, as it supplies the physician with the most convenient and effectual antidote against the effects of the poison.

If a solution of albumen, for example that procured by beating white of eggs in water, is dropped by degrees into a solution of corrosive sublimate, a white flaky precipitate is immediately thrown down, which when separated and dried forms horny masses, hard, brittle, and pulverizable. The precipitate is soluble in a considerable excess of albumen; so that wherever albumen abounds in any fluid, to which corrosive sublimate has been added, a portion of the mercury will always be found in solution. The precipitate is also soluble in a considerable excess of corrosive sublimate. The dry precipitate I have found to contain 6 per cent. of metallic mercury.

The action of casein as it exists in milk is precisely the same. A solution of corrosive sublimate, poured into a large quantity of milk, causes no change; but if the proportion of salt be considerable, a flaky coagulum is formed, and the milk becomes clear. The principles, osmazôme and gelatin, are similar in their effects, though not quite so powerful. Urea has no chemical action with corrosive sublimate. Of the compound animal fluids, blood and serum have the same effects as albumen.

Many insoluble animal principles, as well as all the soft solids of the animal body, act in the same manner with vegetable gluten. Fibrin, for example, coagulated albumen, or coagulated casein, acts precisely in the same way. Muscular fibre, the mucous and serous membranes, the fibrous textures, and the brain, have all the same effect: they become firmer, brittle, white, and a white powder detaches itself from their surface, which contains mercury and animal matter. This chemical action, which Taddei has proved to take place in the living[^[845]] as well as in the dead body, is the source of the corrosive property of the poison, as was first pointed out by Berthollet in his essay formerly quoted.

In all of the compounds thus formed by vegetable and animal substances, the presence of mercury is easily proved by boiling the powder in a solution of caustic potass. The organized matter is dissolved; a heavy, grayish-black powder is formed, which is protoxide of mercury; and if this be collected in the way formerly described, it forms running quicksilver when heated.

A difference of opinion prevails as to the nature of the changes effected by the mutual action of corrosive sublimate and organic matter. For example, in the instance of the action of albumen, which has been most carefully examined, Berzelius and Lassaigne[^[846]] regard the precipitate as a compound of bichloride of mercury with albumen. Professor Rose and Dr. Geoghegan[^[847]] have proved it, in their opinion, to be a compound of binoxide of mercury and albumen without any chlorine. And according to Boullay it is composed of albumen in union with calomel.[^[848]] Lassaigne says he has found it to be a compound of ten equivalents of albumen with one of mercury, or 93·33 per cent. of the former, and 6·67 of the latter.[^[849]] The compound with fibrin he considers to be analogous in composition.

With regard to the changes induced by these effects of organized matter on the operation of the liquid tests for corrosive sublimate, it will in the first place be manifest that the poison may thus be wholly removed from their sphere of action: it may be thrown down as an insoluble substance, on which any process by liquid tests hitherto mentioned will of course fail to act. But secondly, even when a moderate quantity does remain in solution, the operation of the liquid tests, as formerly noticed under the head of each, will be materially modified. It is of some moment for the medical jurist to remember, that by reason of the slowness with which the changes in question sometimes takes place, the poison may exist abundantly in solution at one time, and yet be present only in small quantity after an interval of some hours or days.

Process for Organic Mixtures.—Various processes have been proposed for detecting corrosive sublimate in organic mixtures. The first I shall mention is one proposed by myself in former editions of this work. It is a double one; of which sometimes the first part, sometimes the second, sometimes both may be required. The first removes the corrosive sublimate undecomposed from the mixture, which may be accomplished when its proportion is considerable; the second, when the proportion of corrosive sublimate is too small to admit of being so removed, separates from the mixture metallic mercury; and the analyst will know which of the two to employ by using the protochloride of tin as a trial-test in the following manner.

A fluid mixture being in the first instance made, if necessary, by dividing and bruising all soft solids into very small fragments, and boiling the mass in distilled water, a small portion is to be filtered for the trial. If the protochloride of tin causes a pretty deep ash-gray or grayish-black colour, the first process may prove successful; if the shade acquired is not deep, that process may be neglected, and the second put in practice at once.

First branch of the Process.—In order to remove the corrosive sublimate undecomposed, the mixture, without filtration, is to be agitated for a few minutes with about a fourth part of its volume of sulphuric ether; which possesses the property of abstracting the salt from its aqueous solution. On remaining at rest for half a minute or a little more, the etherial solution rises to the surface, and may then be removed by suction with the pipette (Fig. 8). It is next to be filtered if requisite, evaporated to dryness, and the residue treated with boiling water; upon which a solution is procured that will present the properties formerly mentioned as belonging to corrosive sublimate in its dissolved state. This branch of the process is derived from one of Orfila’s methods.

Second branch of the Process.—If the preceding method should fail, or shall have been judged inapplicable, as will very generally be the case, the mixture is to be treated in the following manner. In the first place, all particles of seeds, leaves, and other fibrous matter of a vegetable nature, are to be removed as carefully as possible. This being done, the mixture, without undergoing filtration, is to be treated with protochloride of tin as long as any precipitate or coagulum is formed. If there were solid animal matters in the mixture, besides being cut and carefully bruised as directed above, they should also be brought thoroughly in contact with the salt of tin by trituration. The mixture, even if it contains but a very minute proportion of mercury, will acquire a slate-gray tint, and become easily separable into a liquid and coagulum. The coagulum is to be collected, washed and drained on a filter; from which it is then to be removed without being dried; and care should be taken not to tear away with it any fibres of the paper, as these would obstruct the succeeding operations. The mercury exists in it in the metallic state for reasons formerly mentioned.

The precipitate is next to be boiled in a moderately strong solution of caustic potass contained in a glass flask, or still better in a smooth porcelain vessel glazed with porcelain; and the ebullition is to be continued till all the lumps disappear. The animal and vegetable matter, and oxide of tin united with them, will thus be dissolved; and on the solution being allowed to remain at rest, a heavy grayish-black powder will begin to fall down in a few seconds. This is chiefly metallic mercury, of which, indeed, globules may sometimes be discerned with the naked eye or with a small magnifier.

In order to separate it, leave the solution at rest under a temperature a little short of ebullition for fifteen or twenty minutes, or longer, if necessary. Fill up the vessel gently with hot water without disturbing the precipitate, so that a fatty matter, which rises to the surface in the case of most animal mixtures, may be skimmed off first with a spoon, and afterwards with filtering paper. Then withdraw the whole supernatant fluid, which is easily done on account of the great density of the black powder. Transfer the powder into a small glass tube, and wash it by the process of affusion and subsidence till the washings do not taste alkaline. Any fibrous matter which may have escaped notice at the commencement of the process, and any lumpy matter which may have escaped solution by the potass, should now be picked out. The black powder is the only part which should be preserved. If the quantity of powder is very minute, an interval of twelve hours should be allowed for each subsidence, and the tube represented in Fig. 7 should be used.

Lastly, the powder is to be removed, heated, and sublimed, as in the last stage of the process described in page [293], for detecting corrosive sublimate in a pure solution.

The second branch of this process is very delicate. I have detected by it a quarter of a grain of corrosive sublimate mixed with two ounces of beef, or with five ounces of new milk, or porter, or tea made with a liberal allowance of cream and sugar. I have also detected a tenth part of a grain in four ounces of the last mixture, that is in 19,200 times its weight.

It may be applied successfully and without difficulty to a very large majority of medico-legal cases. The only difficulty in the way of applying it to all organic mixtures whatever arises from the occasional presence of some vegetable matters, such as seeds, leaves, ligneous fibre and the like, which are insoluble in caustic potass, and which may therefore be left behind with the mercurial precipitate, and obstruct the subsequent sublimation of the metal. This difficulty may be sometimes got rid of, as recommended above, by picking such matters out of the mixture before the protochloride of tin is added. No mercury is lost by so doing, for none of it is united with these vegetable matters: corrosive sublimate does not form any chemical compound with them as it does with other vegetable matters soluble in caustic potass, and with the soft animal solids. When the particles are too small to admit of being thus removed, or cannot be afterwards removed during the process of washing the black powder, which is left after the action of potass—the analyst must be content with the increased facility of sublimation derived from the abstraction of other vegetable and animal admixtures, and take care to use a tube of greater length and with a larger ball than usual. If the sublimate is too much obscured by empyreumatized matter to exhibit distinctly its metallic, globular appearance, the portion of the tube is to be broken off, and scraped, washed, and boiled with a little rectified spirit in a tube. If the globules do not then become visible, a second sublimation will render them distinct. This supplemental operation, however, will be very seldom required; and the process given above will be found to apply to a great majority of instances.

Various objections brought against this process by reviewers and others were noticed in previous editions of this work. The result of the investigation is, that, though not by any means a perfect process, it is one of the most convenient and certain, and least fallacious of all yet proposed. The first step for separating corrosive sublimate by ether in the undecomposed state,—which is borrowed from a suggestion of Professor Orfila, will seldom succeed; for the poison is seldom present in sufficient quantity.

It must be observed that this as well as every other method yet proposed for discovering corrosive sublimate in compound mixtures merely indicates the presence of mercury, and does not point out its state of combination. More especially, in the case of the contents of the stomach, if mercury be not obtained from the filtered fluid, it is impossible to know whether what is detected in the solid matter only may not have proceeded from calomel given medicinally. This objection can be obviated solely by sufficient evidence that calomel was not administered; at least the different criterions laid down by Professor Orfila for distinguishing calomel in the alimentary canal from the products of the decomposition of corrosive sublimate do not appear sufficiently precise, or commonly applicable.[^[850]]

Various processes for detecting corrosive sublimate in organic mixtures have been proposed by others. But none of these seem to me preferable to the method detailed above, with the exception of one which has been lately proposed by Professor Orfila, and which is particularly deserving of notice, because, although complex, he has found it sufficiently manageable and delicate for detecting mercury in the animal textures and secretions, into which it has obtained admission through the medium of absorption in cases of poisoning with the compounds of mercury. Like the previous process, however, it merely detects mercury, and cannot point out the state of combination in which mercury was administered, or mixed with the substance examined.

If the suspected matter be sufficiently liquid, boil for a few minutes and filter; acidulate the product with a few drops of hydrochloric acid; and immerse some slips of copper-leaf in it for a few hours. Should they be tarnished, dissolve oxide and chloride of copper from the surface by means of ammonia; wash them and press them between folds of filtering paper; cut them in pieces, and heat these in a glass tube. Globules of mercury may be obtained or not. In either case, let the liquid, in which the plates were first immersed, be evaporated to dryness over the vapour-bath; add to the residue a sixth of sulphuric acid in a retort with a receiver; and heat gently till a nearly dry carbonaceous mass be obtained. Boil this with an ounce and a half of nitro-hydrochloric acid [Edin. Pharm.], until the charcoal be again nearly dry. Heat what remains with boiling distilled water, filter, apply to a small part of the liquid the copper test as just described, and try whether corrosive sublimate can be detached from the remainder by means of sulphuric ether (p. [299]). The distilled fluid in the receiver may contain corrosive sublimate in considerable proportion, relatively to what existed in the subject of analysis. In order to discover it, boil the liquid for fifteen minutes with nitro-hydrochloric acid; transmit chlorine gas for an hour, filter, and evaporate to dryness over the vapour-bath; dissolve the residue in water, and search for corrosive sublimate both by copper plates, and by agitation with ether.

If mercury be not thus detected, proceed to the solid matter left on the filter, by which the subject of analysis was in the first instance separated into a liquid and solid part. Examine this by evaporation to dryness over the vapour-bath, and charring with sulphuric acid in a retort with a receiver attached; and then subject the product to the same steps as those detailed above for the dried residuum of the liquid part.

If the materials for analysis be soft solids, especially the stomach, intestines, liver, and the like, commence at once with the process of charring with sulphuric acid. In the case of the urine, examine both the liquid and sediment. Filter the liquid, transmit chlorine to excess, let the product rest twenty-four hours, filter, evaporate to dryness, dissolve the residue in water acidulated with hydrochloric acid, and test the solution both with copper-leaf and by agitation with ether. Heat the sediment with nitro-hydrochloric acid as directed above, and then proceed as with the liquid portion of the urine.[^[851]]

Some other processes, but probably inferior to that of Professor Orfila, will be found in the last edition of this work. It seems unnecessary to reproduce them here.

6. Of Bicyanide of Mercury.

The bicyanide of mercury is a compound of mercury and cyanogen. It is usually sold in the form of white, opaque, heavy, crystals, which are rhomboidal prisms. It has a disagreeable, corrosive, metallic taste. It is easily known from every other substance by the effects of heat. If a small quantity of it, previously well dried, be introduced into a glass phial to which a small tube is fitted by means of a cork, on the application of heat the salt becomes black; mercury is sublimed, and condenses in globules on the upper part of the phial; and a gas escapes, which has the odour of prussic acid, and burns with a beautiful rose-red flame.

7. Of the Nitrates of Mercury.

The nitrates of mercury are used in some of the arts, but have so rarely been the cause of injury to man that they are of little medico-legal importance. I am acquainted with only one case of poisoning with them.[^[852]]

There are two nitrates, the protonitrate and pernitrate. 1. The protonitrate is in transparent colourless crystals, entirely soluble in water with the aid of a slight excess of nitric acid; and the solution is precipitated black by the alkalis, black by sulphuretted-hydrogen, white by muriatic acid, and yellow by hydriodate of potass. The crystals when heated discharge fumes of nitrous acid, and when the whole acid is driven off the red oxide is left, which by farther heat is converted into metallic mercury. 2. The pernitrate is similarly affected by heat. Its crystals form white or yellowish needles. Water decomposes them, separating an insoluble yellowish subnitrate, and dissolving a supernitrate, which is precipitated yellow by the alkalis, black by sulphuretted-hydrogen, carmine-red by the hydriodate of potass. Copper separates mercury from both nitrates; and so does gold or platinum when aided by a galvanic current.

Section II.—Of the mode of Action of Mercury and the Symptoms it excites in Man.

The effects of mercury on the animal body are more diversified than those of any other poison. It acts on a great number of important organs, and in consequence the phenomena of its action are proportionately various. It is not surprising, therefore, that some ambiguity still prevails as to its mode of action and the circumstances by which the action is regulated.

The attention of toxicologists in their physiological researches has been chiefly turned to the more active preparations of mercury, and especially to corrosive sublimate, when given in such quantity as to prove fatal in a few days at farthest. The more immediate and prominent properties of corrosive sublimate have consequently received some elucidation. But its qualities as a slow poison, as well as the analogous operation of the less active compounds of mercury, have not been experimentally examined with the same care: indeed it is questionable whether the phenomena of the latter description as they occur in man can be studied with much advantage by means of experiments on animals.—In treating of the mode in which the compounds of mercury act, the most convenient method will be to consider at present its action in the form of corrosive sublimate in large doses as ascertained by late experiments, and to reserve the consideration of the general action of mercurial poisons at large till their effects on man have been fully described.

The mode of action of corrosive sublimate has been examined particularly by Sir B. Brodie in 1812;[^[853]] by Dr. Campbell in 1813,[^[854]] by M. Smith in 1815,[^[855]] by M. Gaspard in 1821,[^[856]] and more lately by Professor Orfila.[^[857]] The following is a short analysis of their experiments and results.

The leading phenomena remarked by Sir B. Brodie, on large doses being introduced into the stomach, were very rapid death, corrosion of the stomach, and paralysis of the heart. In rabbits and cats, from six to twenty grains, injected in a state of solution into the stomach, produced in a few minutes insensibility and laborious breathing, then convulsions, and death immediately afterwards,—the whole duration of the poisoning varying from five to twenty-five minutes. After death the inner membrane of the stomach was gray, brittle, and here and there pulpy,—changes precisely the same with those produced by corrosive sublimate on the dead stomach. When the chest was opened immediately after death, the heart was found either motionless or contracting feebly; and in both circumstances the blood in its left cavities was arterial.

These experiments make it evident that the brain was acted on as well as the heart, and that the immediate cause of death was stoppage of the heart’s action. But they do not show whether the action takes place through absorption, or by a primary nervous impression transmitted along the nerves.

I am not acquainted with any other experiments of consequence on the operation of corrosive sublimate when introduced into the alimentary canal. But some interesting observations have been made by Campbell, Smith, Gaspard, and Orfila severally as to its effects when applied to the cellular tissue or injected at once into the blood of a vein. It follows from their researches, taken along with those of Sir B. Brodie, that, like arsenic, corrosive sublimate is an active poison, to whatever part or tissue in the body it is applied.

Campbell, Smith, and Orfila all agree in assigning to it dangerous properties, when it is applied to a wound or the cellular tissue of animals. Even in the solid state, and in the dose of three, four, or five grains only, it causes death in the course of the second, third, fourth, or fifth day. The symptoms antecedent to death are generally those of dysentery; and corresponding appearances are found after death, namely, redness, blackness, or even ulceration of the villous coat of the stomach and rectum, the intermediate part of the alimentary canal being sound. This poison, therefore, has, like arsenic, the singular power of inflaming the stomach and intestines, even when it is introduced into the system through a wound.

But this is not its only property in such circumstances. According to Smith and Orfila, it also possesses the power of inflaming both the lungs and the heart. Orfila found the lungs unusually compact and œdematous in some parts; and Smith observed on their anterior surface black spots, elevated in the centre, evidently the consequence of effusion of blood. As to the heart, in one of Smith’s experiments black spots were found in its substance, immediately beneath the lining membrane of the ventricles; and Orfila invariably found in one part or another of the lining membrane, most commonly on the valves, little spots of a cherry-red or almost black colour; nay, on one occasion he observed these spots so soft that slight friction made little cavities. The production of pneumonia by corrosive sublimate when applied to a wound appears well established; but the appearances assumed as indications of carditis are equivocal, since they may have arisen simply from dyeing of the membrane of the heart in the fluid part of the blood after death.

The researches of Gaspard were confined to the effects of the poison when injected at once into the blood. They show still more clearly its tendency to cause inflammation of the lungs; and they prove that through the channel of the blood, as through the cellular tissue, it is apt to cause inflammation of the stomach and rectum. The symptoms were vomiting, bloody diarrhœa, difficult breathing, apparent pain of chest, and bloody sputa; and death took place in a few seconds or in three or four days, according to the dose, which varied from one to five grains. The appearances in the dead body were principally redness in the mucous membrane of the intestines; and in the lungs, according to the length of time the animal survived, either black ecchymosed spots, or black tubercular masses, some inflamed, others gangrenous, others suppurated, or finally, regular abscesses separated from one another by healthy pulmonary tissue.[^[858]]

Besides the effects mentioned in the preceding abstract, two of the experimentalists referred to have likewise observed in animals the same remarkable operation on the salivary organs which forms so conspicuous a feature in the action of the compounds of mercury on man. Dr. Campbell observed mercurial fetor, and M. Gaspard mercurial salivation. Another writer, Zeller, found that dogs might be made to salivate, but not graminivorous animals.[^[859]] Schubarth, however, remarked profuse salivation in a horse, to which twenty-four ounces of strong mercurial ointment were administered in the way of friction in sixteen days:[^[860]] and I observed the same symptoms in a rabbit on the sixth day after the commencement of daily mercurial inunction.

The result of the preceding inquiry is, that corrosive sublimate causes, when swallowed, corrosion of the stomach, and in whatever way it obtains entrance into the body, irritation of that organ and of the rectum, inflammation of the lungs, depressed action and perhaps also inflammation of the heart, oppression of the functions of the brain, inflammation of the salivary glands. These phenomena are diversified enough. But it will presently be found that other organs still are implicated in its effects on man.

Before proceeding, however, to its effects on man, some notice may be taken of a question, connected with its mode of action, which has long been the subject of controversy. The experiments already quoted render it probable that corrosive sublimate, before it can exert its remote action, must enter the blood; and the facts to be enumerated under the next head of the present section will render it probable that the milder compounds of mercury used in medicine also act in a similar manner. Physicians and chemists, therefore, long sought to discover this metal in the solids and fluids of the body while under its influence; and the failure of some attempts to detect it has naturally led to its presence throughout the system being called in question by many. This inquiry, besides its interest in a physiological point of view, is highly important in respect to medico-legal practice, since it forms a material branch of the general questions which at present occupy the attention of medical jurists,—whether poisons that act through the blood should be sought for by chemical analysis in other parts of the body besides the stomach, intestines, or other organ to which they have been directly applied—and in what particular quarters the search should be principally made.

In the case of mercury, the evidence of the absorption of the poison, and of its entering the tissues and secretions of the body, is now unimpeachable. This is chiefly derived from observations and experiments made on man and animals after the long-continued use of the milder preparations of mercury; it being imagined that if the poison enters the blood at all, the greatest quantity will be found under these circumstances. The facts may be arranged under three heads. Some relate to the discharge of metallic mercury from the living body during a mercurial course for medicinal purposes; others to the discovery of metallic mercury in the dead body after a mercurial course, and others to the detection of mercury by a careful chemical analysis in the fluids and solids during life or after death.

Many stories are related by the older authors of the discharge of running quicksilver from the living body during a mercurial course. Some of the most authentic of them have been collected by Zeller. In his list of cases it is stated that Schenkius met with an instance of the discharge of a spoonful of quicksilver by vomiting; that Rhodius twice remarked quicksilver pass with the urine; and that Hochstetter once saw it exhaled with the sweat.[^[861]] Fallopius likewise states, that in people who had used mercurial inunction for three years, and who had the bones of the leg laid bare by suppurating nodes, he had seen quicksilver collected in globules on the tibia; and he speaks of its being the practice in his day to draw the mercury from the body, when overloaded with it, by successively amalgamating a bit of gold in the mouth and heating the amalgam to expel the mercury.[^[862]] With regard to these statements of the older authors it may be observed that, although their singularity renders them questionable, they ought not to be rejected at once, as some have done, merely because corresponding facts have not been witnessed in modern times; for no one can now-a days have such opportunities for observation as were enjoyed by Fallopius and his contemporaries. The experiment of amalgamating gold in the mouth of a person under a course of mercury has always failed in modern times. But who can now have an opportunity of making the experiment during a mercurial course of three years? Besides, the statements quoted above are not all destitute of modern confirmation. Thus Fourcroy has noticed the case of a gilder attacked with an eruption of little boils, in each of which was contained a globule of quicksilver. Bruckmann mentions the case of a lady who subsequently to a course of mercury remarked after a dance many small black stains on her breast, and minute globules of quicksilver in the folds of her shift.[^[863]] And Dr. Jourda has described in a late French periodical a case where fluid mercury was passed by the urine. The last fact appears satisfactory in all its circumstances. A patient had been taking corrosive sublimate for a month in the dose of a grain, besides using for the first sixteen days a gargle containing metallic mercury finely divided. Towards the close of the month he observed on the sill of the window, on which he used to turn up his chamber-pot after using it, many little globules of mercury, amounting in all to four grains. Dr. Jourda on learning this observation of his patient collected some of the urine with care, and after it had stood some time found in it a black, powdery sediment, which, when separated and dried, formed little globules of mercury.[^[864]]

The next class of facts in favour of the entrance of mercury into the blood are derived from the discovery of the metal in the bodies of persons who had undergone a long mercurial course recently before death. In the German Ephemerides it is said that no less than a pound of it was found in the brain and two ounces in the skull-cap of one who had been long salivated.[^[865]] This is certainly too marvellous a story. But analogous observations have been made lately. In Hufeland’s Journal it is mentioned that a skull found in a churchyard contained running quicksilver in the texture of its bones, and that there is preserved in the Lubben cabinet of midwifery a pelvis infiltered with mercury, and taken from a young woman who died of syphilis.[^[866]] An unequivocal fact of the same nature has been related by Mr. Rigby Brodbelt. In a body of which he could not learn the history he found mercurial globules as big as a pin-head lying on the os hyoides, laryngeal cartilages, frontal bone, sternum, and tibia.[^[867]] Another equally unquestionable fact of the kind has been supplied by Dr. Otto. On scraping the periosteum of several of the bones of a man who had laboured under syphilis, he remarked minute globules issuing from the osseous substance: in some places globules were deposited between the bone and periosteum, where the latter had been detached in the progress of putrefaction; and in other places, when the bones were struck, a shower of fine globules fell from them.[^[868]] Wibmer observes that Fricke, surgeon to the Hamburg Infirmary, has obtained mercury by boiling the bones of persons who had been long under a course of mercurial inunction.[^[869]]

The third and most satisfactory class of facts are the result of actual chemical analysis. These results were long variable. On the one hand, Mayer, Marabelli,[^[870]] and Devergie,[^[871]] failed to detect mercury in the fluids of people under a mercurial course; and I myself,[^[872]] as well as Dr. Samuel Wright,[^[873]] had no better success in some experiments on animals. On the other hand, Zeller detected it after death in the blood and bile, Cantu procured it from the urine, Buchner found it in the blood, saliva, and urine, and Schubarth extracted it from the blood. The first experimentalist found that in the blood and bile of animals killed by mercurial inunction, mercury could be detected by destructive distillation, but not by any fluid tests.[^[874]] Cantu, by operating on sixty pounds of urine, taken from persons under the action of mercury, procured no less than twenty grains of the metal from the sediment.[^[875]] The experiments of Buchner are very satisfactory. By destructive distillation of the crassamentum of seven ounces of blood taken from a patient who was salivated by mercury, he obtained rather more than a quarter of a grain of globules; two pounds of saliva yielded in the same way a 200th of a grain; and the urine contained so much that it became brownish-black with sulphuretted-hydrogen.[^[876]] Buchner likewise adds, that Professor Pickel of Würzburg procured mercury by destructive distillation from the brain of a venereal patient who had long taken corrosive sublimate.[^[877]] Not less satisfactory are the experiments of Dr. Schubarth. A horse after being rubbed for twenty-nine days with mercurial ointment to the total amount of eighty ounces, died of fever, emaciation, diarrhœa, and ptyalism. On the sixteenth day, when ptyalism had set in, a quart of blood was drawn from the jugular vein, and after death another quart was collected from the heart, great vessels and lungs,—extreme care being taken to collect it perfectly pure. In each specimen there was procured by destructive distillation a liquor, in which minute metallic globules were visible. A copper coin agitated in the liquor was whitened; and when the oily matter was separated by filtration and boiling in alcohol, the residue gave with nitric acid a solution, which produced an orange precipitate with hydriodate of potass.

These researches were considered adequate to prove the strong probability of the absorption of mercurial preparations when introduced into the animal. But the frequency with which negative results were obtained by competent inquirers, and in circumstances apparently favourable, threw an air of doubt over the positive facts, however clear they seem to be in themselves,—till at length Professor Orfila proved by a series of careful experiments that the cause of failure must generally have been the want of a process sufficiently delicate: for in all ordinary circumstances, by using his process described above, he succeeded in obtaining mercury in the urine and liver of animals poisoned with corrosive sublimate, as well as in the urine of patients who were taking that salt in medicinal doses. He could not detect it, however, in the blood.[^[878]] Since these investigations, Professor Landerer of Athens detected mercury in the brain, liver, lungs and spinal cord of a man who poisoned himself with two ounces and a half of corrosive sublimate;[^[879]] and M. Audouard has twice found it in the urine and once in the saliva of persons salivated with mercury, by simply transmitting chlorine, exposing the liquid to the air for a day, evaporating it nearly to dryness, dissolving the residue in water slightly acidulated with hydrochloric acid, immersing copper-leaf for twenty-four hours, and heating the stained portions in a tube.[^[880]]

The cases of poisoning with the preparations of mercury, which have been observed in the human subject, may be conveniently arranged under three varieties. In one variety the sole or leading symptoms are those of violent irritation of the alimentary canal. In another the symptoms are at first the same as in the former, but subsequently become united with salivation and inflammation of the mouth, or some of the other disorders incident to mercurial erethysm, as it is called. In a third variety the preliminary stage of irritation in the alimentary canal is wanting, and the symptoms are from beginning to end those of mercurial erethysm in one or another of its multifarious forms.

The first variety of poisoning with mercury is remarked only in those who have taken considerable doses of its soluble salts, particularly corrosive sublimate. The second is produced by the same preparations. The third may be caused by any mercurial compound.

1. The symptoms in the first variety are very like what occur in the ordinary cases of poisoning with arsenic,—namely, vomiting, especially when any thing is swallowed, violent pain in the pit of the stomach, as well as over the whole belly, and profuse diarrhœa. But there exist between the effects of the two poisons some shades of difference which it is necessary to attend to.

In the first place,—taking corrosive sublimate as the best example of the preparations which cause this variety of poisoning with mercury,—the symptoms generally begin much sooner than those caused by arsenic. The symptoms of irritation in the throat may begin immediately, nay, even during the very act of swallowing;[^[881]] and those in the stomach may appear either immediately,[^[882]] or within five minutes.[^[883]]

Secondly, the taste is much more unequivocal and strong. Even a small quantity of corrosive sublimate, either in the solid or fluid state, and considerably diluted, has so strong and so horrible a taste, that no one could swallow it in a form capable of causing much irritation in the stomach, without being at once made sensible by the taste that he had taken something unusual and injurious. Occasionally, indeed, persons thus warned of their danger while in the act of swallowing the poison, have stopped in time to escape fatal consequences.[^[884]]

Thirdly, the sense of acridity which it excites in the gullet during the act of deglutition, and throughout the whole course of the subsequent inflammation of the alimentary canal, is usually much stronger. If the dose be not small, or largely diluted, or in the solid form, the sense of tightness, acridity, or burning in the throat and gullet during deglutition is often far greater than ever occurs at any stage in the instance of arsenic; and sometimes it is very severe even when corrosive sublimate is taken in the solid form.[^[885]] The tightness and burning in the throat often continue throughout the whole duration of the poisoning; and may be so excessive as to cause complete inability to swallow,[^[886]] or even to speak.[^[887]] Occasionally the affection of the throat is the only material injury inflicted by the poison, as in a case related by Dr. J. Johnstone of a young woman, who tried to swallow two drachms of corrosive sublimate in the solid state, but was unable to force it down on account of the constriction it caused in the gullet. She died in six days of mortification of the throat.[^[888]] The greater violence of the action of corrosive sublimate on the throat, compared with that of arsenic, is evidently owing to its greater solubility and powerful chemical operation on the animal textures.

Fourthly, instead of the contracted ghastly countenance observed in cases of poisoning with arsenic (but which, it will be remembered, is not invariable in that kind of poisoning), those who are suffering under the primary effects of corrosive sublimate have frequently the countenance much flushed, and even swelled.[^[889]]

Corrosive sublimate seems to occasion more frequently than arsenic the discharge of blood by vomiting and purging,—obviously because it is a more powerful local irritant.

It likewise gives rise more frequently to irritation of the urinary passages. This irritation generally consists in frequent, painful micturition; but the secretion of urine is often suppressed altogether. Instances of this kind have been related by Mr. Valentine,[^[890]] by my colleague, Professor Syme,[^[891]] by an anonymous writer in the Medical and Physical Journal,[^[892]] by Dr. Venables,[^[893]] by Mr. Blacklock,[^[894]] and by M. Ollivier, in whose case, however, the poison was the bicyanide of mercury.[^[895]] In the last three cases the suppression was total, and continued till death; which did not ensue, in one till eight, in the next till five, and in the last till nine days after the poison was taken. Sometimes, as in Ollivier’s case, the urinary irritation is attended with symptoms of excitement of the external parts, such as swelling and blackness of the scrotum and erection of the penis.

Another distinction seems to be that corrosive sublimate is more apt than arsenic to cause nervous affections during the first inflammatory stage. The tendency to doze, which sometimes interrupts the inflammatory symptoms caused by arsenic, has been more frequently observed in cases of poisoning with corrosive sublimate.[^[896]] The same may be said of tremors and twitches of the extremities. Sometimes the stupor approaches even to absolute coma;[^[897]] and the twitches occasionally amount to distinct, nay violent convulsions.[^[898]] In other instances paraplegia has been witnessed.[^[899]]

Another difference is, that the effects of mercurial irritants are fully more curable than those of arsenic. Recovery has taken place even after half an ounce was swallowed, with the effect of inducing both bloody vomiting and purging.[^[900]] This may depend in part on the greater solubility of mercurial preparations, so that they are more easily discharged than arsenic, which often remains in the stomach after days of continual vomiting,—and in part on corrosive sublimate and other soluble salts of mercury being converted, in no long time and much more easily, into comparatively innocuous compounds, either by antidotes intentionally given for the purpose, or by animal principles in the secretions and accidental contents of the alimentary canal.

Lastly, deviations from the ordinary course and combination of the symptoms appear to be more rare in the instance of corrosive sublimate than in that of arsenic.

To these general statements, it may be right to add the heads of one or two actual cases, lest an exaggerated idea be conveyed of the combination of the symptoms as they usually occur. For this purpose it will be sufficient to refer to a fatal case related by M. Devergie, to an instance of recovery, without salivation having supervened, which is contained in Orfila’s Toxicology, and to another by Dr. Vautier, presenting the mildest possible symptoms of this variety. In Devergie’s case, the patient, a female, swallowed three drachms of corrosive sublimate in solution, and was soon after seized with vomiting, purging, and pain in the belly. In five hours, when she was first seen by Devergie, the skin was cold and damp, the limbs relaxed, the face pale, the eyes dull, and the expression that of horror and anxiety. The lips and tongue were white and shrivelled; and she had dreadful fits of pain and spasm in the throat whenever she attempted to swallow liquids, also burning and pricking along the course of the gullet, and increase of pain in these parts on pressure. There was likewise frequent vomiting of mucous and bilious matter, with burning pain in the stomach and tenderness of the epigastrium on the slightest pressure. She had farther profuse diarrhœa, with pricking pain and tenesmus. The pulsation of the heart was deep and slow, the pulse at the wrist almost imperceptible, and the breathing much retarded. In eighteen hours these symptoms continued without any material change; but the limbs were also then insensible. In twenty-three hours she died in a fit of fainting, the mind having been entire to the last.[^[901]]—Orfila’s case was that of a gentleman who drank by mistake an alcoholic solution of corrosive sublimate, but fortunately was so much alarmed by its taste while drinking it, that he did not finish the poisonous draught. Nevertheless, he was instantly attacked with a sense of tightness in the throat and burning in the stomach, and then with vomiting and purging. Two hours after the accident Orfila found him with the face very full and red, the eyes sparkling and restless, the pupils contracted, and the lips dry and cracked. There was also acute pain along the whole course of the alimentary canal, particularly in the throat. The belly was swelled, and so tender that he could not bear the weight of fomentation-cloths. The pulse was 112, small and sharp; the skin intensely hot and pungent; micturition scanty, frequent, and difficult; the breathing very much oppressed; the purging bilious. The patient had likewise a tendency to doze, and was affected with occasional convulsive twitches of the face and extremities, and with constant cramps in the limbs. Next morning all the symptoms were sensibly mitigated; and they went on decreasing till convalescence was established in eight days. In the course of a few weeks he recovered his usual health, without suffering salivation.[^[902]]—In Vautier’s case, where sixteen grains had been swallowed, the patient was immediately attacked with pain in the throat and stomach, cold extremities, trembling of the arms and legs, vomiting, paleness of the features, and great feebleness of the pulse. Vomiting being promoted by frequent draughts of warm water, and white of egg given subsequently, no further symptoms ensued, those first excited slowly subsided, and in a few days recovery took place, without any salivation. Yet it was upwards of half an hour before any measures could be taken for his relief.[^[903]]

The only material and common symptom which was wanting in the case now related was blood in the stools and in the matter vomited. In other respects they are good examples of the ordinary train of symptoms in cases of the present variety. For other examples of the same nature the reader may refer particularly to the paper of Mr. Valentine, who has described five cases that happened at one time in the same family, the mother having attempted to poison herself and four children.[^[904]]

It may sometimes be necessary to know the usual duration of this variety of mercurial poisoning, and also the extremes of its duration. On these points I have not hitherto had opportunities of consulting a sufficient number of cases to be able to lay down the general rule with precision. But, so far as my inquiries go, the ordinary duration in fatal cases is from twenty-four to thirty-six hours. It is probable that a few may last three days,[^[905]] but only one instance has come under my notice where the duration was greater; and in that instance, which is described by Dr. Venables, life was prolonged under great agony from pain of the belly, bloody vomiting, diarrhœa and suppression of urine, but without salivation, for no less than eight days.[^[906]] In cases of recovery the symptoms of irritation may continue very long, and nevertheless not pass into the second variety of this kind of poisoning,—a transition, however, which on the whole is uncommon. In the case of which an analysis has been given from Orfila’s narrative, and likewise in one of Mr. Valentine’s patients who recovered, the symptoms all along were those of irritation in the alimentary canal; there was not any ptyalism, or other symptom of proper mercurial erethysm.—The shortest duration yet recorded is two hours and a half. This was in a case related by Dr. Bigsby of Newark-on-Trent, where a tea-spoonful of a concentrated solution of nitrate of mercury was swallowed by a lad sixteen years old, and where the chief symptoms were burning pain from the mouth to the stomach, tenderness of the whole belly, mucous vomiting, and feculent purging.[^[907]] In a case which occurred in London, and which has been published succinctly by Mr. Illingworth, death must have occurred either as soon, or very shortly afterwards. The dose of corrosive sublimate, though not positively ascertained, was large.[^[908]] Next to this the shortest case recorded proved fatal in eleven hours.[^[909]]

2. The second variety of poisoning with mercury comprehends the cases, which begin, like the former, with irritation in the alimentary canal, but in which the symptoms of what is called mercurial erethysm gradually supervene. In fatal cases of this description death sometimes arises from the primary action of the poison, exactly as in the previous variety; but in other instances it is owing to general disturbance of the constitution, or the local devastation, brought on by the secondary effects.

It is unnecessary to describe here the several forms of mercurial erethysm which may thus be developed, because they will immediately be considered under the third variety of mercurial poisoning. It is sufficient to state in passing that the leading affection is inflammation of the organs in and adjoining the mouth, and more particularly of the salivary glands.

But it may be right to endeavour in the present place to fix the period of the poisoning at which these secondary affections may and usually do commence. This cannot be done so satisfactorily as might be wished, because the cases already published which I have been able to examine do not form a large enough induction. Among the recorded cases I have hitherto seen, salivation has never been retarded beyond the third day;[^[910]] but in an instance of suicide by corrosive sublimate which happened in the Castle of Edinburgh in 1826, and which was communicated to me by the late Dr. Shortt, the salivation did not begin till the fourth. Salivation seldom comes on sooner than the beginning of the second;[^[911]] and the most usual date of its commencement is towards the close of the second day. There is little doubt that it may be retarded till a period considerably later than I have yet found recorded. It is doubtful whether true mercurial salivation ever begins much sooner than after the first twenty-four hours. Occasionally, however, corrosive sublimate produces salivation of a different kind, which has been mistaken for the specific variety caused by mercury. Thus in a paper on the cure of gonorrhœa by corrosive sublimate in single large doses, communicated by Mr. Addington of West Bromwich to Dr. Beddoes, it is stated that a grain and a half, taken at once in half an ounce of rectified spirit, causes immediately “a great burning in the throat and stomach, and quickly afterwards a copious salivation, lasting between an hour and a half and two hours, and amounting frequently to more than a quart.”[^[912]] These facts have been appealed to by authors in medical jurisprudence as proving the rapid production of mercurial salivation. But the effect produced is not the specific ptyalism of mercury; for its brief duration is scarcely consistent with this supposition. And farther, the author goes on to observe, that, if the dose be taken on going to bed, the latter part of the night is passed quietly, and no inconvenience is felt afterwards, even when the dose is taken five or six times at intervals of three or four days. The effects here observed is a sympathetic phenomenon depending on the topical action of the poison. And such, I have no doubt, has been the nature of the salivation in several cases of poisoning with corrosive sublimate, which have been supposed to be at variance with the general rule, that this affection does not begin till about twenty-four hours have elapsed. Such seems to have been the nature of the salivation in a case published by Dr. Perry,[^[913]] that of a girl who was attacked with swelling of the cheeks and lower lip, burning in the throat, flushed face, feeble pulse, and cold, clammy extremities after swallowing corrosive sublimate, and who had a copious flow of saliva in an hour and a half; for there is no mention made of fetor, and the girl was well enough to leave the hospital in a few days,—which could scarcely happen if she had been affected with ptyalism from the constitutional action of mercury.—In like manner Dr. Alexander Wood has related a case, fatal in fourteen days, in which the patient said salivation came on in seven hours.[^[914]] But, notwithstanding Dr. Wood’s argument in support of the patient’s statement,—for he did not see him till nine days after the poison was taken,—there is no satisfactory evidence that the salivation was the true constitutional salivation of mercury, and not simply the result of its topical action, which seems to have been very severe.—Farther, in an instance related by Dr. H. Anderson of Belfast, where salivation appeared to him to begin in nineteen hours, it seems not improbable that he mistook for mercurial ptyalism the common salivation arising from inability to swallow on account of sore throat; for this patient too was quite convalescent in three days.[^[915]]—Mr. Alfred Taylor alludes to a case in Guy’s Hospital of salivation occurring in four hours; but so briefly, that its true influence on the present question cannot be judged of.[^[916]]—On the whole, then, although it is clear that ptyalism of one kind or another may occur very soon after corrosive sublimate is swallowed, it remains a matter of doubt, whether the true, specific ptyalism, depending on the constitutional action of the poison begins sooner than after an interval of above twenty-four hours.

As to the total duration of this variety in fatal cases, I have found an instance fatal on the fourth day, salivation having begun on the second;[^[917]] and Orfila quotes a case from Degner, in which the gastro-enteritic symptoms were succeeded by ptyalism about the same period, and which proved fatal in fifteen days.[^[918]] These periods, however, probably do not form the extremes; for in such cases as the former death is the consequence of the primary affection, and may therefore ensue immediately after the secondary stage has begun to develope itself; and when death arises from profuse salivation, as in Degner’s patient, or from the ravages committed by ulceration and gangrene, it may be delayed almost as long as in cases of the third variety of mercurial poisoning, in which there is no precursory stage of inflammation in the alimentary canal.

Death may arise, not only from the primary action of the poison, or from the exhaustion caused by mercurial erethysm, but likewise from incidental occurrences. Thus, in Dr. Alexander Wood’s case, referred to above, death arose directly from sudden profuse hemorrhage from the bowels, to the amount of six pounds.

The present variety of poisoning with corrosive sublimate may be concluded with the heads of an excellent example related in the Medical and Physical Journal. The patient, a stout young girl, swallowed soon after supper a drachm of corrosive sublimate dissolved in beer, and in a few minutes she was found on her knees in great torture. All the primary symptoms of this kind of poisoning were present in their most violent form,—burning in the stomach, extending towards the throat and mouth, followed in no long time by violent vomiting of a matter at first mucous, afterwards bilious and bloody; by purging of a brownish, fetid fluid; suppression of urine and much tenderness of the urethra and bladder; small, contracted, frequent pulse, anxious countenance, and considerable stupor, interrupted frequently by fits of increased pain. All these symptoms were developed in four hours. Subsequently the pain in the stomach became much easier, but that in the throat much worse. At length in the course of the second day, the teeth became loose, the gums tender, the saliva more abundant than natural; profuse ptyalism and great fetor of the breath ensued, and the patient expired towards the close of the fourth day.[^[919]]

3. The third variety of poisoning with mercury comprehends all the forms of what is called mercurial erethysm. Without endeavouring to settle the precise meaning of this term, which is now used in rather a vague sense, I shall consider under the present head all the secondary and chronic effects of mercury. These may be caused by any of its preparations, but are most frequently seen as the consequence of its milder compounds, either given medicinally in frequent small doses, or applied continuously to the bodies of workmen who are exposed by their trade to its fumes.

The secondary and chronic effects of mercury are multifarious enough in reality; but if credit were given to all that has been written, and is still sometimes maintained on this subject, almost every disease in the nosology might be enumerated under the present head; for there is scarcely a disease of common occurrence, which has not been imputed by one author or another to the direct or indirect operation of mercury. The present remarks, however, will be confined as much as possible to what is well ascertained, and bears on the medical evidence of poisoning with mercury, or is important in regard to medical police. With this view, salivation and its concomitants, the most usual of the secondary effects of mercury, will first be treated of. Some observations will then be made on the shaking palsy, or mercurial tremor, which is caused in those who work with mercury. And in conclusion, a short view will be taken of the other diseases which are more indirectly induced by this poison, as well as some which have been ascribed to it on insufficient grounds. This being done, the mode of action of mercurial poisons will be resumed, and a description given of their relative effects when introduced by different channels and in different chemical forms.

Of Mercurial Salivation.—Mercurial salivation may be caused by any of the preparations of mercury, and either by a single dose or by frequently repeated small doses. It may be caused by corrosive sublimate as the secondary stage of a case which commenced with inflammation in the alimentary canal; or it may be the first sign of mercurial action, as in the medicinal mode of administering calomel and blue pill. Even in the latter case a single dose, and that not large, may be sufficient to induce ptyalism of the most violent kind. When induced by a single dose it usually commences between the beginning of the second and end of the third day, rarely within twenty-four hours. But an extraordinary case is mentioned by Dr. Bright, where five grains, put on the tongue in apoplexy and not washed over, excited in three hours most violent salivation, with such swelling of the tongue that scarifications became necessary.[^[920]] It commences with a brassy taste and tenderness of the mouth, swelling, redness, and subsequently ulceration of the gums; peculiar fetor of the breath; and at last an augmentation is observed in the flow of the saliva, commonly accompanied with fulness around the lower jaw. These symptoms increase more or less rapidly. Sometimes they are very mild; nay, this form of the secondary effects of mercury may consist in nothing else than brassy taste, tenderness of the mouth, redness of the gums, and fetor. On the other hand, the symptoms are often very violent, the salivation being profuse, the face swelled so as to close the eyes, and almost fill up the space between the jaw and clavicles, the tongue swollen so as to threaten suffocation, the inside of the mouth ulcerated, nay gangrenous, and at times the gangrene extends over the face. It is not uncommon to observe severe and extensive ulceration without particular increase of the saliva.

These local affections are almost always accompanied with more or less constitutional disorder. If severe, they are attended with the symptomatic fever proper to inflammation and gangrene, from whatever cause they spring. But independently of that, mercurial salivation is accompanied, and indeed commonly preceded, by a constitutional disorder or symptomatic fever of its own, which occasionally exhibits some peculiarities. The mildest affection of the mouth and salivary glands is very generally preceded by some exaltation of the pulse and temperature, and other symptoms of fever. But when the local disorder begins violently, and above all when this takes place by idiosyncrasy from small doses of mild preparations, there is often great rapidity of the pulse, irregular action of the heart, and various nervous disorders possessing the hysteric character,—all of which, except the quick pulse, will sometimes gradually abate or even disappear, when the salivation is fairly established.

The phenomena of ordinary mercurial salivation being familiar to every practitioner, it is unnecessary to quote here any illustrative example; but the following instance may be given to exemplify its most malignant forms. A patient of Mr. Potter of Chipping-Ongar, in Essex, after taking eighteen grains of blue pill in divided doses during three days, was seized with excessive salivation and great constitutional disturbance, indicated by offensive evacuations, copious sweating, bleeding from the nose, purple spots on the skin, dilated pupils, and such severe local disease that the teeth dropped out, and he expired six days after mercurial action set in.[^[921]]

As the phenomena of mercurial salivation have been often known to lead to important evidence and much contrariety of opinion upon trials, it will be necessary to dwell at some length on some parts of the subject.

In the first instance, then, the dose which is required to bring on salivation may be noticed. It is needless to mention the ordinary quantity required in mercurial courses. A more useful object of consideration is the departure from the ordinary rule. One of the most common and important of these deviations is excessive sensibility to the action of mercury, in consequence of which the individuals who have this idiosyncrasy may be profusely salivated by one or two small doses even of the mildest preparations. Three grains of corrosive sublimate divided into three doses have caused violent ptyalism.[^[922]] Fifteen grains of blue pill, taken in three doses, one every night, have excited fatal salivation.[^[923]] Nay, two grains of calomel have caused ptyalism, extensive ulceration of the throat, exfoliation of the lower jaw, and death.[^[924]] Three drachms of mercurial ointment applied externally have caused violent ptyalism and death in eight days. On the other hand, it is well known that some constitutions resist the action of mercurials very obstinately, so as even sometimes to appear incapable of being salivated at all. I have more than once met with cases of the last description, where mercurial courses had been continued for three months and upwards without avail. It may be added, that, except in constitutions naturally predisposed to suffer from a few small doses, a few large doses do not appear apt to excite severe salivation, or even to cause any at all. This has been clearly shown in the course of the practice lately introduced of administering calomel in doses of a scruple. On that subject more will be said by and by. At present I may mention, that, in conformity with the practice alluded to, I have several times, in various diseases, given eight or ten grains of calomel five or six times a day for two or three days together, without observing that ptyalism was apt to ensue.

The next point to be considered is, whether mercurial salivation can be confounded with any other affection. In a very difficult case of poisoning which was tried here in 1817, that of William Patterson for murdering his wife,[^[925]] it appeared probable that he had given her repeatedly large doses of calomel. But the proof of this was circumstantial only, and an important circumstance in the chain of evidence was a deposition to the occurrence of salivation during the woman’s illness. This fact, however, rested on the skill and testimony of a quack doctor only; and the admissibility of such a person to decide on a point of this nature, will depend on the facility with which the true mercurial form of salivation can be recognised. This statement will show the practical object of what is to follow.

Many other causes may excite a preternatural flow of saliva. Several other poisons may have that effect, for example, preparations of gold, preparations of copper, antimony, croton-oil, and foxglove: foxglove has been known to cause violent salivation for three weeks.[^[926]] Opium too has occasionally excited salivation,[^[927]] and also hydrocyanic acid and iodide of potassium.

Even a common sore throat, if the swelling and pain are so great as to render swallowing very difficult and distressing, may be accompanied, as every physician must have remarked, with a profuse flow of saliva; and in the ulcerative stage there is also often a fetor that is hardly distinguishable from the mercurial kind. In the ulceration of the mouth called cancrum oris there is some salivation with great fetor of the breath.

Salivation likewise forms an idiopathic disease, and may then be both profuse and obstinate. Mr. Davies has described a case of spontaneous ptyalism which had lasted for a fortnight before he was called to see the patient; and during all that time the quantity of saliva discharged was two or three pints daily. How long it endured afterwards he does not mention; but it must have continued for some time, because during his attendance first one physician and then another were called into consultation with him. Laxatives slowly removed it. Mr. Davies has not described the state of the mouth; but the first physician mistook the salivation for a mercurial one.[^[928]] In the same journal which contains this case another has been related which lasted four months.[^[929]] Another very remarkable case has been recorded by Mr. Power. The patient, a young lady, discharged for more than two years from sixteen to forty ounces of saliva daily. In the last two cases the mouth was not affected.[^[930]] Two other instances have been related by M. Bayle, in one of which the patient was cured after spitting five pounds daily for nine years and a half; while the other continued to be affected after spitting profusely for three years. In neither was there any ulceration of the mouth.[^[931]] An instance has been related by an Italian physician, Dr. Petrunti, where, in the course of various nervous affections of the hysteric character, the patient became affected with heat and tightness in the throat, and so profuse a salivation for two months, that between three and four pounds were discharged daily.[^[932]] A case somewhat similar is related in Rust’s Magazin of a man who suffered upwards of two years from a daily salivation alternating occasionally with a mucous discharge from the bowels or lungs.[^[933]] M. Guibourt describes the case of a lady who had an attack of profuse salivation every thirty, forty, or fifty days, lasting between twenty-four and forty-eight hours, and unaccompanied with any other affection of the mouth or adjoining parts except a sense of tightness in the throat.[^[934]] M. Gorham relates an interesting case of a lady who in three successive pregnancies was attacked soon after impregnation with excessive ptyalism, which continued to the extent of between two and four quarts daily until the period of quickening on two occasions, and on the third till her delivery; but there was never any fetor or any affection of the gums.[^[935]] I have likewise met with a singular case where spontaneous ptyalism accompanied an ulcerated sore throat of the mercurio-syphilitic kind. The patient had taken mercury to salivation about six months before coming under my care, and got completely rid of both the sore throat and salivation. But the sore throat returned, together with the salivation, two months before I saw him, and the salivation continued for two months longer to the extent of twenty or even thirty ounces daily,—the ulcer of the throat during that interval being sometimes healed up, and again returning as severely as ever. In three weeks more the discharge rapidly diminished, and ceased. During all the time he was under my care there was no fetor of the breath, and no redness, ulceration, or sponginess of the gums. A singular account of an epidemic salivation which occurred in connection with a continued tertian fever, has been given in an inaugural dissertation contained in one of Haller’s Collections. The author, Quelmalz, says that the ptyalism sometimes continued for three weeks, that it was in one instance as great in extent as the most violent mercurial salivation, and that it was accompanied by fetor, superficial ulceration of the mouth, pustules on the tongue, relaxation of the gums, and looseness of the teeth.[^[936]]

Salivation may likewise be produced by the influence of the imagination. I have seen a singular example of this. A woman who had a great aversion to calomel was taking it with digitalis for a dropsical complaint. Some one having told her what she was using, she immediately began to complain of soreness of the mouth, salivated profusely, and even put on the expression of countenance of a salivating person, although she had taken only two grains. On being persuaded, however, that she had been misinformed, the discharge ceased gradually in the course of one night. Two days afterwards she was again told on good authority that calomel was contained in her medicines, upon which the salivation began again and was profuse. It did not last above twenty-four hours; but the symptoms during that period resembled a commencing mercurial salivation in every thing but the want of fetor and redness of the gums.

In general, mercurial salivation may be easily distinguished from all the preceding varieties by an experienced practitioner. If its progress has been traced from the first appearance of brassy taste and fetor to the formation of ulcers and supervention of ptyalism, no attentive person can run any risk of mistaking it. Its characters are also quite distinct at the time salivation just begins. The fetor of the breath and sponginess and ulceration of the gums at this stage distinguish it from every other affection. But if the state of the mouth is not examined till the ulcers have existed several days, the characters of the mercurial disorder are much more equivocal. They cannot be distinguished, for example, from some forms of idiopathic ulceration of the mouth connected with unsoundness of the constitution, and characterized by extensive sloughing, ptyalism, and gangrenous fetor.[^[937]] In particular they cannot be distinguished from the effects of the disease called cancrum oris. A few years ago indeed a London physician was charged, in consequence of this resemblance, with having killed, by mercurial salivation, a patient to whom it was proved that he had not given a particle of mercury, and who clearly died of the disease in question;[^[938]] and a similar case, where fatal mercurial salivation was suspected, but which was clearly proved on a Coroner’s Inquest to have been also a case of cancrum oris, has been more lately published by Mr. Dunn.[^[939]]

For distinguishing these and such other affections from mercurial salivation Dr. Davidson of Glasgow has lately proposed a character, the exact scope of which cannot yet be appreciated,—namely, that in true mercurial salivation there is never any sulpho-cyanic acid in the saliva; so that sesquichloride of iron does not render it red. The presence of sulpho-cyanic acid may possibly prove that salivation is not mercurial; but the converse does not hold good, because other causes tend to deprive human saliva of its sulpho-cyanic acid.[^[940]]

The next point to be noticed regarding mercurial salivation is, that a long interval may elapse after the administration of the mercury has been abandoned, before the effect on the salivary glands and mouth begins,—mercury in small doses being what is called a cumulative poison, or a poison whose influence accumulates silently for some time in the body before its symptoms break forth. Swédiaur has met with instances where the interval was several months,[^[941]] Cullerier with a case in which it was three months.[^[942]] It will at once be seen how strongly such facts may bear on the evidence in a criminal case, where the administration of mercury in medicinal doses, which have been long abandoned, is brought forward to account for salivation, appearing weeks or months after, and giving rise, in conjunction with other circumstances, to a suspicion of mercurial poisoning of more recent date.

Another question which has been made the subject of discussion is the duration of mercurial ptyalism. The medical witness may be required to give his opinion how long this affection may last after the administration of mercury has been abandoned. The present question may be cut short by stating, that there appears to be hardly any limit to its possible duration. Linnæus met with an instance of its continuing inveterately for a whole year;[^[943]] Swédiaur says he has known persons languish for months and years from its effects;[^[944]] and M. Colson knew an individual who had been salivated for six years.[^[945]] These, however, are very rare incidents. After an ordinary mercurial course the mouth and salivary glands generally return to the healthy state in the course of a fortnight or three weeks.

A fifth question, whether the ptyalism, or, speaking in general terms, the erethysm of mercury, is susceptible of a complete intermission, formed a material subject of inquiry, and the cause of much contradictory statement on a noted criminal trial, that of Miss Butterfield in 1775 for the murder of her master, Mr. Scawen. She was accused of administering corrosive sublimate; and it was alleged in her defence, that the salivation and consequent sloughing of which he died might have arisen, without the fresh administration of mercury, from the renewal of a previous ptyalism, which had been brought on by a common mercurial course, and had ceased two months before the second salivation began. It appeared that Mr. Scawen was salivated with a quack medicine from the beginning till the middle of April; and that about the middle of June he was again seized with violent salivation, of which he died. It was rendered very improbable, that during the interval between the two salivations any more mercury had been taken medicinally. The question then was, whether the original ptyalism could have reappeared after so long an interval, without the fresh administration of mercury? The witnesses for the prosecution, gentlemen in extensive practice, said it could not. But one of the prisoner’s witnesses, Mr. Bloomfield of the London Lock Hospital, said he had repeatedly known salivation reappear after a long intermission; that it was quite common for hospital patients to have a second salivation, when thought well enough to go out the next dismissal day;[^[946]] that in one case the interval was three months; and that one of his patients was attacked periodically with salivation at intervals of six weeks or a month for a whole year. Mr. Howard, another surgeon of the Lock Hospital, deposed to the same effect; and the prisoner was acquitted, apparently upon their evidence.[^[947]]

Notwithstanding what was said by these gentlemen, I believe the recurrence of mercurial salivation after so long an interval, without the repetition of mercury, is exceedingly rare. Dr. Gordon Smith, in alluding to the trial of Miss Butterfield, has mentioned a case which occurred to the late Dr. Hamilton of this University, and used to be related by him in his lectures. The interval was so great as four months.[^[948]] Mr. Green of Bristol has lately described another unequivocal case, where the interval was six weeks.[^[949]] Dr. Mead says he met with an instance where the interval was six months;[^[950]] and Dr. Male mentions another where mercury brought on moderate salivation in March, and after a long interval excited a fresh salivation in October, of which his patient died in a few weeks.[^[951]] M. Louyer-Villermé met with a case, where, in consequence of exposure to cold, a sudden attack of salivation was caused a twelvemonth after the removal of syphilis by mercury.[^[952]] Some other cases not less wonderful have been recorded by M. Colson in his paper on the effects of mercury. He quotes Dr. Fordyce for the case of a man who had repeated attacks of salivation, with metallic taste, which lasted for three weeks, although mercury had not been taken for twelve years; and Colson himself knew a surgeon who had a regular and violent attack of all the symptoms of mercurialism eight years after he had ceased to take mercury.[^[953]] It is impossible to attach credit to such marvellous stories as the last two. Granting the ptyalism to be really mercurial, it would require much better evidence than any practitioner could procure, to determine the fact that mercury had not been given again during the supposed interval. This objection indeed will apply more or less even to the instances where the alleged interval did not exceed a few months.

The last point to be noticed regarding mercurial salivation is the manner in which it proves fatal. Death may ensue from the mildest preparations, and from the smallest doses, in consequence of severe salivation being produced by them in peculiar habits. Two instances have been already mentioned which illustrate both of these statements, and others might easily be referred to were the fact not familiar.

Death may be owing to a variety of causes. Some of those which have been assigned are direct and unquestionable in their operation; others indirect and more doubtful.

The most direct and obvious manner is by extensive spreading gangrene of the throat, mouth, face, and neck. The late happy changes, introduced into the treatment of syphilis and other diseases which are benefited by mercury, render this mode of death rare in the present day. Yet I may mention that I have seen an example of it in a woman who was salivated to death, because her medical attendant, a firm believer in the powers of mercury as an antidote, forgot that the antidote is itself a poison, if not given in moderation. In general, when gangrene is the cause of death, it begins within the mouth or in the throat, and spreads from that till it even reaches the face. But sometimes it begins at once on the external surface, at a distance from the primary ulcers. An example of such a progress of the symptoms has been related by Dr. Grattan. A child ten years old was violently salivated by twenty grains of calomel given in six days. On the fifth day of the salivation, a little vesicle appeared on the skin near the mouth on each side, and was the commencement of a gangrenous ulcer, which spread over the whole cheek, and proved fatal eight days after its appearance.[^[954]]

Another cause of death appears to be exhaustion from profuse and protracted discharge of saliva, without material injury of the mouth or adjoining organs.

A third manner of death which I have witnessed is exhaustion from laryngeal phthisis; and from the circumstances of the case, I have little doubt but, in the state to which patients are then sometimes reduced, death may also take place suddenly from suffocation. My patient had undergone before I saw him five long salivations for a venereal complaint, and had latterly been attacked with symptoms of ulceration of the glottis. This affection went on slowly increasing, and he died of exhaustion after many weeks of suffering. During this period he was repeatedly attacked with alarming fits of suffocation, which were relieved by the hawking of mucous flakes. The symptoms were explained on dissection by the appearance of extensive ulceration and thickening of the glottis, and almost total destruction of the epiglottis.

The other causes of death are more indirect, and will be mentioned presently. They depend on the pre-existence of other diseases, on which mercury acts deleteriously during the state of erethysm excited by it in the constitution.

Of Mercurial Tremor.—The second division of the secondary effects of mercury comprehends the palsy or tremor, with the collateral disorders induced in miners, gilders, and other workmen, whose trade exposes them to the operation of this poison. Under the present head, which might be treated at considerable length as an important branch of medical police, I shall confine myself chiefly to an analysis of an interesting essay by Mérat on the Tremblement Metallique, and to some remarks by Jussieu on the health of the quicksilver miners of Almaden in Spain.

Mérat’s account of the shaking palsy induced by mercury is very interesting.[^[955]] The disease, he states, may sometimes begin suddenly; but in general it makes its approaches by slow steps. The first symptom is unsteadiness of the arms, then quivering, finally tremors, the several movements of which become more and more extensive till they resemble convulsions, and render it difficult or impossible for the patient to walk, to speak, or even to chew. All voluntary motions, such as carrying a morsel to the mouth, are effected by several violent starts. The arms are generally attacked first and also most severely. If the man does not now quit work, loss of memory, sleeplessness, delirium, and death ensue. But as the nature of the disease soon renders working almost impossible, he cannot well continue; and in that case death is rare. The concomitant symptoms of the trembling are a peculiar brown tint of the whole body, dry skin, flatus, but no colic, no disorder of respiration, and, except in very old cases, no wasting or impaired digestion. The pulse is almost always slow.—This description agrees with a somewhat later account of the disease by Dr. Bateman, as he observed it in mirror-silverers;[^[956]] and also with some interesting cases recently published by Dr. Bright.[^[957]]

In general the tremors are cured easily, though slowly, several months being commonly required. One of Dr. Bright’s patients got almost well in little more than a fortnight under the use of sulphate of zinc. Sometimes, however, the trembling is incurable.[^[958]] I have said the disease is rarely fatal. Mérat quotes three cases only, in one of which death was owing to profuse salivation and gangrene, in the others to marasmus. On the whole, those who are liable to the shaking palsy do not appear liable to salivation. Yet the two affections are sometimes conjoined, as in three of the cases described by Dr. Bright, and in some noticed by Mr. Mitchell among the mirror-silverers of London.[^[959]] Gilders, miners, and barometer-makers are all subject to the disease. Even those who undergo mercurial frictions may have it, according to Mérat; and M. Colson, who confirms this statement, quotes Swédiaur as another authority for it.[^[960]] It is not merely long-continued exposure to mercurial preparations that causes the shaking palsy: a single strong exposure may be sufficient; and the same exposure may cause tremor in one and salivation in another. Professor Haidinger of Vienna some time ago mentioned to me an accident a barometer-maker of his acquaintance met with, which illustrates both of these statements. This man and one of his workmen were exposed one night during sleep to the vapours of mercury from a pot on a stove, in which a fire had been accidentally kindled. They were both most severely affected, the latter with salivation, which caused the loss of all his teeth, the former with shaking palsy, which lasted his whole life.

In regard to all such workmen, it is exceedingly probable that with proper care the evils of their trade may be materially diminished. This appears at least to be the result of the observations made long ago by Jussieu on the miners of Almaden in La Mancha. Most quicksilver mines are noted for great mortality among the workmen. But Jussieu maintains that the trade is not by any means so necessarily or so dreadfully unhealthy as is represented, or as it really is in some places. The free workmen at Almaden, he says, by taking care on leaving the mine to change their whole dress, particularly their shoes, preserved their health, and lived as long as other people; but the poor slaves, who could not afford a change of raiment, and who took their meals in the mine, generally without even washing their hands, were subject to swelling of the parotids, aphthous sore throat, salivation, pustular eruptions, and tremors.[^[961]]

Of the indirect effects of mercurial erethysm.—The last division of the secondary effects of mercury relates to its indirect action when concurring with other diseases or predispositions to disease.

Of these effects there are some of which the poison appears to be the chief, if not even the sole cause. Thus, during the symptomatic fever which precedes salivation there are sometimes remarked imitative inflammations, or coma, or affections of the heart, which go off as salivation is established.

Other effects require the distinct co-operation of collateral causes. Many inflammatory diseases, not easily excited in ordinary circumstances, arise readily from improper exposures during salivation, for example dropsy, pneumonia, phrenitis, iritis, erysipelas, and various chronic eruptions.

Other effects again require the co-operation of disease, such as sloughing gangrene supervening on ordinary ulcers during the action of mercury,—a not uncommon accident. This appears most likely to happen when the ulcers are constitutional.

Lastly, in conjunction with other diseased morbid actions, either going on at the same time, or immediately preceding mercurial erethysm, this poison is apt to occasion some modifications of disease which are rarely otherwise witnessed. Modifications of the kind have already been traced in the instances of lues venerea and scrofula; but there is reason to believe that the same singular property may also exist in relation to other constitutional disorders.

These observations conclude the inquiry into the symptoms caused in man by mercurial poisons generally. Returning now to its mode of action, we have to examine its relative effects through the different animal textures, and in its various chemical forms.

The result of the previous remarks as to its action on animals, it will be remembered, was, that its soluble preparations cause when swallowed corrosion of the stomach, and in whatever way it enters the body irritation of the stomach and rectum, inflammation of the lungs, depressed action and perhaps inflammation of the heart, oppression of the functions of the brain, and inflammation of the salivary glands. All of these effects have likewise been mentioned in the preceding sketch, as occurring in a greater or less degree in consequence of its operation on man.

Mercury acts as a poison on man in whatever way it is introduced into the body,—whether it be swallowed, or inhaled in the form of vapour, or applied to a wound, or even simply rubbed or placed on the sound skin. But the kind of action excited differs according to the channel by which it is introduced.

The most ordinary and dangerous cases of poisoning arise from the introduction of corrosive sublimate into the stomach. The poison then kills by corroding or inflaming the alimentary canal, or by causing salivation and its concomitants.

When applied to a wound or ulcer corrosive sublimate does not often occasion dangerous symptoms. Yet it is sometimes a hazardous remedy. It is not a convenient escharotic even in a concentrated state; for its escharotic action is not incompatible with its absorption; at all events it certainly sometimes acts constitutionally through the surface of wounds and ulcers, and the symptoms brought on in this way are generally violent. They are the symptoms of mercurial salivation, accompanied at times with well-marked inflammation of the alimentary canal. When applied to sores in a diluted state it has also been known to cause dangerous effects if too long persevered in. A case of the kind has been related by Mr. Robertson, an army-surgeon. After anointing an itchy eruption of the arms for seven days with a solution of corrosive sublimate containing five grains to the ounce, his patient was attacked with fever, inflammation of the stomach and bowels, and in two days more with violent salivation.[^[962]] A case of the same nature has been related by Mr. Sutleffe.[^[963]] His patient, a child, in consequence of having an eruption of the head washed with a solution of corrosive sublimate, was attacked with violent salivation, which proved fatal in a few days. Pibrac has recorded three fatal cases from the free application of corrosive sublimate to ulcerated surfaces. One of these proved fatal in five days, another in twenty-four hours, and a third during the night after the poison was applied. The symptoms generally indicated violent action on the alimentary canal.[^[964]] In an instance mentioned by Degner, fatal in twenty-five days, there was also violent irritation of the stomach; but the chief affection was excessive swelling of the face and throat, together with profuse ptyalism.[^[965]]

One of the readiest modes of bringing the system under the poisonous action of mercury is by introducing its preparations into the lungs. It appears from some experiments by Schlöpfer that the fluid preparations act rapidly through the lining membrane of the air-passages. Six grains of corrosive sublimate in solution will thus kill a rabbit in five minutes.[^[966]] But the effects of mercury through this channel are much better exemplified when its preparations are inhaled in the form of vapour. Corrosive sublimate when incautiously sublimed in chemical experiments has been known to cause serious effects. Dr. Coldstream of Leith informs me, that while subliming about twenty-four grains of it with the blowpipe when a student, he and several of his fellow-apprentices were seized with painful constriction of the throat, several had headache, and one had sickness and vomiting. The phenomena produced by the various preparations of mercury in more violent cases, are sometimes protracted tremors,[^[967]] sometimes severe ptyalism and tedious dysentery,[^[968]] sometimes salivation and gangrene of the mouth ending fatally.[^[969]] This last form was produced remarkably in a chimney-sweeper, after cleaning a gilder’s chimney, during which operation he felt a disagreeable sense of tightness in the throat.

Several extraordinary instances have happened of poisoning from long-continued inhalation of the vapours which arise from metallic mercury. That vapours do arise from metallic mercury of the ordinary temperature of the atmosphere has been fully proved by Mr. Faraday; who found, that when a bit of gold was suspended from the top of a phial, the bottom being covered with a little mercury, the gold soon became amalgamated.[^[970]] The vapours thus discharged may produce the worst species of mercurialism, if they are diffused through an apartment insufficiently ventilated. One of the most striking examples known of the baneful effects of mercury thus gradually insinuated into the system, occurred in a well-known accident which befel the ships Triumph and Phipps. These vessels were carrying home in 1810 a large quantity of quicksilver saved from the wreck of a ship near Cadiz, when by some accident several of the bags were burst and the mercury spilled. On the voyage home the whole crews of both vessels were more or less severely salivated, two died, many were dangerously ill, all the copper articles on board became amalgamated, all the rats, mice, cockroaches, and other insects, as well as a canary-bird and several fowls, and all larger animals, such as cats, dogs, goats, and sheep were destroyed.[^[971]]

The action of mercury is often violently excited when it is applied to the skin even not deprived of the cuticle. The effects of mercurial inunction form a well-known and satisfactory proof of this. Even without the aid of infriction, the soluble preparations of mercury will excite mercurial action by being put simply in contact with the skin. Thus it has been shown by a German physician, Dr. Guérard, that ptyalism may be induced by a warm bath of corrosive sublimate in the proportion of an ounce to 48 quarts of water, and that the effect commonly begins after the third bath with an interval of three days between them.[^[972]] It is not so generally known that the more active preparations, such as corrosive sublimate or nitrate of mercury, may, like arsenic, cause through the sound skin effects almost as violent as through the alimentary canal. The following pointed illustration is related by Dr. Anderson. A gentleman affected with rheumatism, was persuaded by a friend to use a nostrum, which was nothing else than a solution of half a drachm of corrosive sublimate in an ounce of rum. This was rubbed on the affected part for several minutes before going to bed. Ere the friction was ended, he felt a sensation of heat in the part, to which, however, he paid little attention. But during the night he was attacked with pain in the stomach, sickness, and vomiting, and soon after with purging and tenesmus. In the morning Dr. Anderson found him very weak and vomiting incessantly. The arm up to the shoulder was prodigiously swelled, red, and blistered. Next day he complained of brassy taste and tenderness of the gums, and regular salivation soon succeeded.[^[973]] Another case of much interest has been described by my colleague, Professor Syme, where a solution of the nitrate was rubbed by mistake upon the hip and thigh instead of camphorated oil. Intense pain immediately followed, and afterwards shivering; the urine was suppressed for five days, without any insensibility, and during its suppression urea was detected in the blood; ptyalism appeared on the third day, became very profuse, and was followed by exfoliation of the alveolar portion of the lower jaw, but recovery nevertheless slowly took place.[^[974]]

The mere carrying of mercurial preparations for a length of time near the skin, though not in direct contact with it, may be sufficient to induce the peculiar effects of the poison, as the following example will show. A man applied to a German physician, Dr. Scheel, affected with violent salivation evidently mercurial which proved fatal, but which it was impossible to trace to its real cause till after death, when a little leathern bag containing a few drachms of mercury was found hanging at his breast; and it was then discovered that he had been in the practice of carrying this bag for six years as a protection against itch and vermin, and during that period had frequent occasion to renew the mercury.[^[975]]

The effects of mercury as a poison differ with the chemical form in which it is introduced into the system.

In its metallic state it is probably inactive. This fact is a material one for the medical jurist to determine precisely; for running quicksilver has been given with a criminal intent. A case of the kind forms the subject of a medico-legal report in Pyl’s Repertory;[^[976]] and another is mentioned in Klein’s Annals.[^[977]]

It is well ascertained that large quantities of fluid mercury have been repeatedly swallowed, without any injury or peculiar effect having followed. In neither of the German cases now referred to was any bad effect produced; and it has proved equally harmless when given medicinally to remove obstruction in the intestines. Farther, M. Gaspard mentions in his paper quoted in a former page, that he has left large quantities shut up for many hours in the various cavities of the body in animals, without observing any other result than at times inflammation, which was evidently owing to the mere presence of a foreign body, and not to the action of an irritant poison.[^[978]]

It has been already stated, however, that the vapours of metallic mercury, even at the temperature of the air, produce mercurialism when inhaled. But then, in all likelihood, some of the metal is oxidated before being inhaled. At least the chemist knows that the surface of a mercurial trough soon tarnishes, especially when the mercury is not pure.

But it may be said that the blue ointment, which is made with running quicksilver, will not act as a mercurial when rubbed upon the skin. Here too, however, some oxidation takes place in the making of the ointment. Mr. Donovan endeavoured to prove that some of the mercury is always oxidated;[^[979]] and I have generally found a sufficient quantity of oxide to account for the effects.[^[980]]

It has been farther said, in proof of the poisonous action of quicksilver in its metallic state,—that patients, who have taken it for obstructed bowels, have sometimes been salivated. This accident has, I believe, happened in a few instances where the mercury was retained long in the body. But such cases are undoubtedly very rare. Zwinger mentions the case of a man, who took four ounces for colic, and was seized in seven days with salivation.[^[981]] Laborde relates the particulars of another instance where seven ounces taken in fourteen days excited ptyalism, ulceration of the mouth, and great feebleness of the limbs.[^[982]] In the days of Dr. Dover, when the administration of large doses of fluid mercury was a fashionable practice for a variety of purposes, it was alleged to have even sometimes proved fatal; and the case of an actor is specially mentioned, to whom, when convalescent from ague, Dover gave mercury to the amount of two pounds in five days, and who at the close of that period was seized with headache, colic, restlessness, and costiveness, proving fatal in two days; and the whole lower intestines were found black and lined with minute metallic globules.[^[983]] Perhaps then it must be admitted that fluid mercury is not altogether inactive, speaking medicolegally. But this admission is no argument in favour of the metal being physiologically a poison; because in the course of the cases referred to, a part is in all likelihood oxidated by the oxygen in the intestinal gases. It is said to have been taken in the dose of an ounce daily for nine months, without either good or harm resulting.[^[984]]

The question regarding the poisonous qualities of running quicksilver was carefully investigated some years ago by the Berlin College of Physicians in a report on the case in Pyl’s Repertory.[^[985]] They observe that the opinion of Pliny, Galen, Hippocrates, Dioscorides, and many of the earlier moderns, including even Zacchias, had led to the popular belief in the deadly properties of fluid mercury; but that this belief is erroneous; for many surgeons, and among the rest Ambrose Paré, had given without injury to their patients several pounds of it to cure obstructed bowels; and in 1515 the Margrave of Brandenburg, over-heated on his marriage night with love and wine, and rising to quench his thirst, drank by mistake a large draught of quicksilver without suffering any harm. Fallopius mentions that he had known instances of women swallowing pounds of mercury, for the purpose of procuring miscarriage, and who did not suffer any injury.[^[986]]

The sulphurets of mercury, like the metal, are not possessed of any deleterious action on the animal body. Orfila found that half an ounce of the sulphuret, formed in a solution of corrosive sublimate by sulphuretted-hydrogen, and half an ounce or six drachms of cinnabar, had no effect whatever on dogs.[^[987]] The sulphurets which have appeared injurious in the hands of Smith[^[988]] and other previous experimentalists must therefore have been impure.

Of the compounds of mercury, the red-precipitate and Turbith-mineral act as irritants, besides possessing the property common to all mercurial compounds, of causing mercurial erethysm. But they are not escharotics, though generally termed such. That is, they do not chemically corrode the animal textures. The effects of red-precipitate have been variable. Mr. Allison relates the case of a girl who in a fit of jealousy swallowed thirty grains of it. Being immediately detected, an emetic was given, which operated freely, and subsequently the stomach-pump was used; but on neither occasion was any red powder brought away. She was attacked with burning pain in the stomach, which was removed by opium, and for a week she had a distaste for food, but no other symptom of consequence.[^[989]] Mr. Brett has described a case, in which the symptoms were occasional vomiting, stupor, languid pulse, cold clamminess of the skin, afterwards severe cramps of the legs, tenderness of the abdomen, dysuria, and some purging, and on the third day ptyalism; but the patient recovered.[^[990]] M. Devergie has given a case somewhat similar, but without any ptyalism having followed the irritant effects of the poison.[^[991]] In 1840 I was consulted on the part of the Crown in the case of a girl, who, there was every reason to suppose, had been killed in twelve hours by red-precipitate. The symptoms towards the close were pain in the throat, inability to swallow, vomiting, and excessive prostration; extensive red patches were found on the villous coat of the stomach after death; and I detected mercury in the solid contents and likewise in the inner coat of the stomach. The case did not go to trial, because, although a man by whom she was pregnant came under some suspicion, it rather appeared that the deceased had herself swallowed the poison with the view of inducing miscarriage. Dr. Sobernheim has given the particulars of the case of a young man who died from swallowing an ounce of red-precipitate. He suffered for some hours from vomiting, diarrhœa, pain in the stomach, tenderness of the belly, and colic; next day he had no pain, but coldness, lividity, stiffness, and an imperceptible pulse; and he expired in thirty-three hours. The poison was found abundantly in the stomach and duodenum after death, and some grains of it rested upon little ulcers.[^[992]] As to Turbith-mineral, two scruples will kill a cat in four hours and a half; and several instances of violent and even fatal poisoning with it are mentioned by the older modern authors.[^[993]]

The white precipitate or chloride of mercury and ammonia is probably also irritant, though inferior in power to the preparations just mentioned. Two scruples given to a dog occasion vomiting, pain, and some diarrhœa; and cases are recorded of death in the human subject from less doses.[^[994]] But there are no recent facts as to the activity of this compound, and the older cases, which would assign to it very great energy, are open to the objection that this preparation was in former times often impure.

The bichloride or corrosive sublimate is a powerful corrosive or irritant, according to the dose and state of concentration; and it also excites mercurial erethysm in a violent degree. The nitrates too are corrosive, and not inferior in activity to the bichloride, as may be inferred from Dr. Bigsby’s case, noticed at page [314].

The bicyanide or prussiate of mercury, from the researches of Ollivier, and an interesting case he has published of poisoning with it in the human subject, appears to resemble corrosive sublimate closely in all its effects, except that it does not corrode chemically. Twenty-three grains and a half proved fatal in nine days.[^[995]] M. Thibert has described a case in which ten grains caused death in the same period of time.[^[996]] The symptoms in both instances were those of severe irritation of the stomach, extensive inflammation of the organs in the mouth, and suppression of urine; and in Thibert’s case a small quantity of albuminous fluid was discharged from the bladder instead of urine.

The protochloride or calomel, and probably also the protoxide, are the most manageable of the preparations of mercury for inducing ptyalism. Calomel is also an irritant; that is, it causes irritation and inflammation in the alimentary canal when swallowed. This part of its properties as a poison will require a word or two of explanation.

Calomel is universally employed as a laxative, but to secure this effect being produced it is commonly combined with other purgatives. When given alone a few grains will in some constitutions induce a violent hypercatharsis; and larger, but still moderate, doses have with most people such a tendency to cause severe griping and diarrhœa as to have led to the practice of combining it with opium when the object is to salivate. These considerations clearly establish that calomel, in a moderate dose of five or ten grains, is an irritant.

It farther appears that in larger doses it is said to have occasionally produced very violent effects, nay, even death itself, by its irritant operation. Hoffmann has mentioned two instances where fifteen grains of calomel proved fatal to boys between the ages of twelve and fifteen. One of them had vomiting, tremors of the hands and feet, restlessness and anxiety, and died on the sixth day. The other, he merely mentions, died after suffering from extreme anxiety and black vomiting.[^[997]] Another fatal case has been related by Ledelius in the German Ephemerides, which was caused by a dose of half an ounce taken accidentally. Vomiting soon ensued, and a sense of acridity in the throat; then profuse diarrhœa to the extent of twenty evacuations in the day; next excessive prostration of strength and torpor of the external senses; and death followed in little more than twenty-four hours.[^[998]] Wibmer quotes Vigetius, an author of the beginning of last century, for a similar case, likewise fatal, which was occasioned by half an ounce,—also Hellweg, a writer of the previous century, for the case of a physician, who took an ordinary medicinal dose by way of experiment, and died in five hours under all the symptoms of violent irritant poisoning.[^[999]]

These observations being kept in view, what explanation will the toxicologist give of the effects which in modern times have been ascribed to large doses of calomel? It was stated not many years ago by several East India surgeons, apparently with the universal assent of their brethren in later times, that this drug in the dose of a scruple administered even several times a day, is not only not an irritant, but even on the contrary a sedative;[^[1000]] and that in some diseases, for example yellow fever, it has been given in the dose of five, ten, or twenty grains, four or six times a day, till several hundred grains were accumulated in the body, yet without causing hypercatharsis, nay, with the effect of checking the irritation which gives rise to black vomit in yellow fever, and to the vomiting and diarrhœa observed in the cholera of the East. It is quite impossible for a European physician to doubt these statements; for all practitioners in hot climates concur in them, and now that analogous practices have been transferred to Britain, repeated opportunities have occurred for establishing the fidelity of the original reporters. Some American physicians, advancing beyond the Hindostan treatment, have since given calomel in bilious fever in the dose of forty grains, one drachm, two drachms, and even three drachms, repeatedly in the course of twenty-four hours for several days together,—and with similar phenomena. In one instance 840 grains were given in the course of eight days in these enormous doses. The largest dose was three drachms; and it was followed by only one copious evacuation, and that not till after the use of an injection.[^[1001]] This practice appears not to have been altogether unknown in former times. Ledelius, the author formerly quoted, states, that he had been accustomed to give doses of a scruple, and that Zwölffer even gave a drachm in one dose.[^[1002]]

It must be also added, that while the facts quoted above from Hoffmann, Ledelius, and others assign to single large doses a powerful and dangerous irritant action, very different results have been occasionally observed in recent times where even so large a quantity as one or two ounces had been taken. Thus, in the case of a lady mentioned by Wibmer, who took by mistake the enormous quantity of fourteen drachms, although acute pain in the belly ensued, together with vomiting and purging, these symptoms were speedily subdued by oleaginous demulcents; and after a smart salivation, she recovered entirely in six weeks.[^[1003]] Another case has been related by Mr. H. P. Robarts, where an ounce was swallowed by a young lady by mistake for magnesia, with no other effect than nausea at first, rather severe griping and slight tenderness of the belly afterwards, and subsequently languor, headache and indigestion; yet the powder was retained two hours.[^[1004]]

It is impossible in the present place to enter into the physiological action of calomel as a remedy; but every one must be satisfied that, with all which has been already written, much still remains to be done before the facts now mentioned can be explained satisfactorily. Can the violent effects described by Hoffmann, Ledelius and Hellweg have arisen from the calomel having been imperfectly prepared and adulterated with a little corrosive sublimate? Or may they be explained by reference to the fact, that the presence of hydrochlorates in solution, particularly hydrochlorate of ammonia, tends to convert calomel into corrosive sublimate.[^[1005]] Mr. Alfred Taylor has made some experiments, to show that the latter explanation will not suffice.[^[1006]]

Meanwhile, taking the facts as they stand, it is plain that great caution must be used in ascribing violent irritant properties generally, or even symptoms of irritant poisoning in a particular case, to large doses of calomel.

With the view of illustrating the importance of the preceding observations, it may be useful to mention here the heads of a case already briefly alluded to for another purpose, the trial of William Paterson for murder ([319]).[^[1007]] His wife during the month previous to her death had two attacks of diarrhœa, with an interval of a fortnight between them. On the second occasion it became profuse and exhausting, but without any material pain or considerable vomiting; looseness of the teeth and salivation ensued, and she died in nine days. On examination of the body, the anus was found excoriated, the whole intestines checkered with dark patches, and the stomach red, ulcerated, and spotted with black, warty excrescences; but the late Dr. Cleghorn of Glasgow could not detect any poison by chemical analysis. It was proved that the prisoner, besides procuring, a few months before his wife’s death, a variety of poisons, such as hydrochloric acid, cantharides, and arsenic, had also on different occasions during her last illness purchased in a suspicious manner four doses of calomel varying from 30 to 60 grains each. Among the various ways in which he was charged with having poisoned the deceased, that which was best borne out by the general as well as medical facts consisted in his taking advantage of an existing inflammation of the mucous membrane of the bowels,—whether arising from a natural cause or from poison it was in this view of the case immaterial to inquire,—and keeping up and aggravating the inflammation by purposely administering at intervals large doses of calomel. On the trial Dr. Cleghorn and other witnesses gave their opinion that the doses purchased by the prisoner, if administered, would cause the symptoms and morbid appearances observed in the case. On the other hand, the late Dr. Gordon deposed to the effect, that all the symptoms of the case might arise under the operation of natural disease, and that such doses of calomel were by no means necessarily injurious; the late Mr. John Bell deposed, that it had even been given in much larger doses without injury; and the profession are now well aware, though not at the time of this trial, that in the very malady alleged by the prisoner to have carried off the deceased, namely dysentery, the administration of calomel in repeated large doses is accounted by many a proper method of cure. The doses purchased by the prisoner were considerably larger, it is true. But there was not any evidence of his having administered his purchases in single doses as he got them; and even though there had been evidence to that effect, it would not remove altogether the difficulty of deciding the question, as to the irritating action of calomel, on which the issue of the trial in one view of the case chiefly depended.

It is probable that all the compounds formed by corrosive sublimate with animal and vegetable substances are feebly poisonous, or at least very much inferior in activity to corrosive sublimate itself. This has been shown by Orfila to be the case with the compound formed by albumen. Sixty grains of this compound, being equivalent to nearly five grains of corrosive sublimate, produced no bad effect whatever on a dog or a rabbit.[^[1008]] The same has been satisfactorily proved by Taddei as to the compound formed by gluten. Twelve grains of corrosive sublimate decomposed by his emulsion of gluten had no effect whatever on a dog.[^[1009]] It is important to remark, however, that if there be an excess of the decomposing principle, so that the precipitate is party redissolved, the irritant action of the corrosive sublimate is not so much reduced, though it is still certainly diminished. Orfila has settled this point in regard to albumen.[^[1010]] The power of producing mercurial erethysm is possessed by all mercurial compounds whatever, and among the rest by the compounds now under consideration.[^[1011]]

The present section may now be concluded with a few remarks on the strength of the evidence derived from the symptoms which are produced by the compounds of mercury.

If the medical jurist should meet with a case of sudden death like that of the animals experimented on by Sir B. Brodie, the symptoms alone could not constitute any evidence of poisoning with corrosive sublimate. All he could say would be that this variety of poisoning was possible, but that various natural diseases might have the same effect. This feebleness in the evidence from symptoms, however, is of little moment; because the dose must be great to cause such symptoms, and little can be vomited before death; so that the poison will be certainly found in the stomach.

Should the patient die under symptoms of general irritation in the alimentary canal, poisoning may be suspected. But it would be impossible to derive from them more than presumptive evidence. The suspicion must become strong, however, if the ordinary signs of irritation in the alimentary canal are attended with the discharge of blood upwards and downwards. And the presumption will, I apprehend, approach very near to certainty,—at least of the administration of some active irritant poison,—if, at the moment of swallowing a suspected article, and but a short time before the symptoms of irritation began in the stomach and bowels, the patient should have remarked a strong, acrid, metallic taste, and constriction or burning in the throat.

When upon all these symptoms salivation is superinduced, the evidence of poisoning with corrosive sublimate or some other soluble salt of mercury is almost unequivocal. That is, if, after something has been taken which tasted acrid, and caused an immediate sense of heat, pricking, or tightness in the throat, the characteristic signs of poisoning with the irritants make their appearance in the usual time, and are soon after accompanied or followed by true mercurial salivation,—it may be safely inferred that some soluble compound of mercury has been taken. Before drawing this inference, however, it will be necessary to determine with precision all the classes of symptoms, more particularly the nature of the salivation. It should also be remembered that salivation may accompany or follow the symptoms of inflammation in the stomach, in consequence of calomel having been used as a remedy. But if proper attention be paid to the fallacies in the way of judgment, I conceive that an opinion on the question of poisoning with corrosive sublimate may be sometimes rested on the symptoms alone. This is another exception to the rule laid down by most modern toxicologists and medical jurists respecting the validity of the evidence of poisoning from symptoms.

For a good example of the practical application of these precepts, the reader may consult the trial of Mr. Hodgson, for attempting to poison his wife. In the instance which gave rise to the trial in question, a violent burning sensation in the throat was felt during the act of swallowing some pills; in the course of ten minutes violent vomiting ensued, afterwards severe burning pain along the whole course of the gullet down to the stomach, next morning diarrhœa, and on the third day ptyalism. There were many other points of medical evidence which left no doubt that corrosive sublimate was swallowed in the pills. But even the history of the symptoms alone would have led to that inference.[^[1012]]

Section III.—Of the Morbid Appearances caused by Mercury.

The morbid appearances observed in the bodies of persons killed by corrosive sublimate will not require many details; since most of the remarks formerly made under the head of the pathology of the irritants generally, and of arsenic in particular, apply with equal force to the present species of poisoning. Still there are some peculiarities deserving of notice, which arise from the greater solubility or stronger irritant action of corrosive sublimate.

The mouth and throat are more frequently affected than by arsenic; and a remarkable appearance sometimes observed, and not excited, so far as I know, by arsenic, is shrivelling of the tongue, with great enlargement of the papillæ at its root.[^[1013]]

The disorder of the alimentary canal is also usually more general, and reaches a greater height before death takes place. Sometimes the irritation and organic injury are confined to the stomach;[^[1014]] but more commonly the throat, stomach, gullet, rectum, nay, even also the colon, are affected. The black or melanotic extravasation into the mucous membrane of the stomach, which has been already several times described as a common effect of the more violent irritants, is also produced by corrosive sublimate. In Devergie’s case and in that of Dr. Venables it was present in a very great degree.[^[1015]]

The coats of the stomach, and also those of the intestines, more particularly the colon and rectum, have frequently been found destroyed. So far as I have been able to ascertain, two kinds of destruction of the coats may be met with,—corrosion and ulceration.

The first is the result of chemical decomposition of the tissues. This kind is evidently to be looked for only when the quantity has been considerable and the dose concentrated. Nay even then it is rare. For on account of the solubility of corrosive sublimate, the facility with which it is decomposed by the secretions or accidental contents of the stomach, and the violence and frequency of the vomiting, this poison is peculiarly liable to be prevented from exerting its corrosive action on the membranes. Hence it is that proper chemical corrosion of the coats of the stomach is seldom witnessed in man.

The appearance of this corrosion differs according to the rapidity of the poisoning. In very rapid cases, for example in animals which have survived only twenty-five minutes, the villous coat has a dark gray appearance, without any sign of vital reaction.[^[1016]] But this variety has never been witnessed in man, in whom the action has been hitherto much less rapid. In the most rapid cases, such as that of Dr. Bigsby, which terminated in two hours and a half ([314]), or those related by Mr. Valentine, of which one ended fatally in eleven and another in twenty-four hours, the corrosion was black, like the charring of “leather with a red-hot coal, and the rest of the stomach scarlet-red or deep rose-red;—showing that inflammation had set in.” In the former of these two cases the corrosion was as big as a half-crown, in the latter three inches in diameter. In a third case, where the patient lived thirty-one hours, the stomach was perforated.[^[1017]] In the case described by Dr. Venables, and formerly alluded to, where life was prolonged for eight days, there was a patch on the under surface of the stomach as large as two crown-pieces, hard, elevated, and of a very dark olive or almost black colour, besides very general erosion of the villous coat.[^[1018]] In all these cases the disintegrated spot was probably situated where the poison first chiefly lodged.

The corrosion caused by mercury, if examined before the slough is thrown off, will be found to possess an important peculiarity: the disorganized tissue yields mercury by chemical analysis. Professor Taddei repeatedly obtained the metal from the membranes of animals which he had poisoned with corrosive sublimate.[^[1019]] It is probable that mercury may be thus detected although death may not have taken place for some time after the poison was swallowed. For the slough was found adhering in one of Mr. Valentine’s cases, where life was prolonged for seventy hours; and it was not entirely removed even in eight days in one of the cases described by Dr. Venables.

Although, however, it is sometimes possible to find the poison in the stomach, the medical jurist must not perhaps expect to find it so often in the present instance as in that of poisoning with arsenic. For on account of its greater solubility corrosive sublimate cannot adhere with such obstinacy to the villous coat, and is therefore more subject to be discharged by vomiting. Nevertheless, the insoluble compound formed by antidotes may adhere to the coats like arsenic, and so resist the tendency of vomiting to displace them. In Devergie’s case, notwithstanding twenty-three hours of incessant vomiting, although no poison could be detected in the fluid contents of the stomach, it was distinctly found in small whitish masses that lay between the folds of the rugæ.[^[1020]]

It may be here farther observed that corrosive sublimate, as well as other salts of mercury, may undergo in the alimentary canal after death the same change which is produced in arsenic from the gradual action of hydrosulphuric acid gas. It may be converted into the sulphuret. I am not acquainted indeed with any actual instance of such conversion; but that it may occur we can scarcely doubt, not merely from theoretical considerations, but likewise because Orfila met with an instance where calomel taken daily in a case of gastro-cephalitis was discharged by stool in the form of a black sulphuret.[^[1021]]

Another important consideration is, that corrosive sublimate may be decomposed and reduced to the metallic state by the admixture of various substances either given at the same time or subsequently, and the longer the inspection is delayed, the more complete will be the decomposition which is accomplished. Iron, zinc, and other metals are the most active of these substances.[^[1022]]

The other forms of destruction of the coats of the alimentary canal is common ulceration, either such from the beginning, or what was originally corrosion converted into an ulcer in consequence of the disorganized spot being thrown off by sloughing.

I have seen this appearance to an enormous extent in the great intestines of a man who survived nine days. Numerous large, black, gangrenous ulcers, just like those observed in bad cases of dysentery, were scattered over the whole colon and rectum. In this instance, which occurred to the late Dr. Shortt, the stomach was also ulcerated, but the small intestines were not.

Sometimes the ulceration seems to be a variety of softening of the mucous tissue, as in a case described by Dr. Alexander Wood of this city, which proved fatal in fourteen days, and in which the stomach, cæcum, and ascending colon presented round, softened, greenish spots about the size of a sixpence, and accompanied in the stomach with a tendency to detaching of the membrane in the form of a slough.[^[1023]]

The destruction of the villous coat of the stomach occasioned by corrosive sublimate and other soluble salts of mercury may be distinguished from spontaneous gelatinization by one of two characters. If the slough remains attached, mercury will be detected in it: if separation has taken place, the ulcer exposed presents surrounding redness and other signs of reaction.[^[1024]]

All the other effects of inflammation may be produced by corrosive sublimate, as by arsenic and other irritants. More frequently here than in the case of arsenic peritonæal inflammation is met with. In Devergie’s case the external surface of the stomach along both its curvatures presented the appearance of red points on a violet ground. In Mr. Valentine’s cases there was much minute vascularity, not only of the outside of the stomach but also of the whole peritonæum lining the viscera and inside of the abdomen; and there was even some serous effusion into the cavity. In Dr. Venables’s case the peritonæal coat of the stomach was highly vascular and inflamed, and the omentum also injected.

The urinary organs, and particularly the kidneys, are often much inflamed by poisoning with corrosive sublimate. Dr. Henry has related a case in which this poison proved fatal on the ninth day, and where the left kidney was found to contain an abscess.[^[1025]] In all of Mr. Valentine’s cases the kidneys were inflamed, and the bladder excessively contracted, so as not to exceed the size of a walnut. In Ollivier’s case, caused by the cyanide of mercury, the scrotum was gorged and black, the penis erected, and the kidneys a third larger than natural. In the case described by Dr. Venables both kidneys, but especially the left, were large, flaccid, and vascular, the ureters turgid and purple, and the bladder contracted, empty, and red internally.

Orfila has observed that the internal membrane of the heart is sometimes inflamed and checkered with brownish-black spots. Some remarks have been already made on the light in which this appearance ought to be viewed by the pathologist (p. [271]).

Whatever may be the real state of the fact as to the alleged power of arsenic to preserve from decay the bodies of those poisoned with it, all authors agree that corrosive sublimate possesses no such property. Yet it is well known to be a good antiseptic, when applied topically. The experiments of Klanck, noticed under the head of Arsenic, prove that corrosive sublimate at all events does not retard putrefaction in the bodies of those poisoned with it; and Augustin in his analysis of Klanck’s researches infers that it even promotes decay.[^[1026]] I have met with one example in the human subject which seems to confirm Augustin’s opinion. In the case formerly quoted from the Medical and Physical Journal, which was fatal in four days, the relater found the body forty-two hours after death so putrid, though in the month of January, that the examination of it was very unpleasant, the belly being black, and a very offensive odour being exhaled.[^[1027]] Little importance, however, can be attached to a solitary case; for on the contrary Sallin relates a case where the body of a man supposed to have been poisoned with corrosive sublimate was found not decayed, but imperfectly mummified, after sixty-seven days.[^[1028]]

It is unnecessary to detail the proofs to be found in the dead body of mercurial salivation having existed during life. They are of course to be looked for in the mouth, and in the adjoining organs. We must not, however, expect to see much appearance of disease in the salivary glands; for according to Cruveilhier, in persons who die of mercurial salivation these glands do not present any trace of inflammation themselves, but merely serous effusion into the cellular tissue around them.[^[1029]]

Professor Orfila has made some useful experiments as to the effects of corrosive sublimate on dead intestine, which it may be proper to notice in a few words. When applied in the form of powder to the rectum of an animal newly killed, the part with which it is in contact becomes wrinkled, and as it were granulated, harder than natural, and of alabaster whiteness, intermingled with rose-red streaks, apparently the ramifications of vessels. When the membrane is stretched upon the finger, the wrinkling disappears. The muscular coat is of a snow-white colour, and even the serous coat is white, opaque, and thickened. The parts not in contact with the powder retain their natural appearance, and the line of demarcation between the affected and unaffected portions is abrupt. If the powder is not applied till twenty-four hours after death, the parts it touches become thick, white, and hard; but no red lines are visible. It is easy to draw the distinction between these appearances and the effects of corrosive sublimate during life.

Little need be said of the force of the evidence of poisoning with corrosive sublimate, derived from the morbid appearances. If the gullet, stomach, and colon be all inflamed and ulcerated, and these injuries have taken place during a short illness, the presumption in favour of some form of irritant poisoning will be strong. And the presumption of poisoning with corrosive sublimate will be strong, if the usual marks of salivation are also found in the mouth and throat. But such evidence can never amount to more than a strong presumption or probability.

Section IV.—Of the Treatment of Poisoning with Mercury.

The treatment of poisoning by the compounds of mercury may be referred to two heads,—that which is required when irritation of the alimentary canal is the prominent disorder, and that which is designed to remove mercurial salivation.

Irritation and inflammation of the alimentary canal are to be treated nearly in the same way as when arsenic has been the poison swallowed. In the instance of corrosive sublimate we also possess a convenient and effectual antidote.

Several substances may be used as antidotes; but those which have hitherto been most employed are albumen and gluten.

It has been already hinted that albumen, in the form of white of eggs beat up with water, impairs or destroys the corrosive properties of bichloride of mercury, by decomposing it and producing an insoluble mercurial compound. For this discovery and the establishment of albumen as an antidote, medicine is indebted to Professor Orfila. He has related many satisfactory experiments in proof of its virtues. The following will serve as an example of the whole. Twelve grains of corrosive sublimate were given to a little dog, and allowed to act for eight minutes, so that its usual effects might fairly begin before the antidote was administered. White of eight eggs was then given; after several fits of vomiting the animal became apparently free from pain; and in five days it was quite well.[^[1030]] According to Peschier the white of one egg is required to render four grains of the poison innocuous.[^[1031]] The experiments of the Parisian toxicologist have been repeated and confirmed by others and particularly by Schloepfer; who found that when a dose was given to a rabbit sufficient to kill it in seven minutes if allowed to act uncontrolled, the administration of albumen, just as the signs of uneasiness appeared, prevented every serious symptom.[^[1032]] Dr. Samuel Wright has found that if the administration of albumen is followed up by giving some astringent decoction or infusion, the beneficial effects are more complete, because the compound formed is less soluble in an excess of albumen.[^[1033]]

The virtues of albumen have also been tried in the human subject with equally favourable results. The recovery of the patient, whose case was quoted formerly (p. [312]), from Orfila’s Toxicology, seems to have been owing in great measure to this remedy. In the Medical Repository another case is related, in which it Was also very serviceable.[^[1034]] A third very apposite example of its good effects is related by Dr. Lendrick. His patient had taken about half a drachm of corrosive sublimate, and was attacked with most of the usual symptoms, except vomiting. White of eggs was administered a considerable time afterwards, the beneficial effects of which were instantaneous and well-marked; and the patient recovered.[^[1035]] A few years ago Orfila’s discovery was the means of saving the life of M. Thenard the chemist. While at lecture, this gentleman inadvertently swallowed, instead of water, a mouthful of a concentrated solution of corrosive sublimate; but having immediately perceived the fatal error, he sent for white of eggs, which he was fortunate enough to procure in five minutes. Although at this time he had not vomited, he suffered no material harm. Without the prompt use of the albumen, he would almost infallibly have perished.[^[1036]]

Albumen is chiefly useful in the early stage of poisoning with corrosive sublimate, and is particularly called for when vomiting does not take place. But it farther appears to be an excellent demulcent in the advanced stages.

On a previous occasion, mention was made of a few of the facts brought forward by Professor Taddei to prove the virtues of the gluten of wheat as an antidote for poisoning with corrosive sublimate [297, 336], so that nothing more need be said on the subject in the present place. As it is difficult to bring the whole of a fluid containing corrosive sublimate into speedy contact with pulverized gluten, which when put into water becomes agglutinated into a mass, the discoverer of this antidote proposes to give it in the form of emulsion with soft soap. This is made by mixing, partly in a mortar and partly with the hand, five or six parts of fresh gluten with fifty parts of a solution of soft soap. And in order to have a store always at hand, this emulsion, after standing and being frequently stirred for twenty-four hours, is to be evaporated to dryness in shallow vessels, and reduced to powder. The powder may be converted into a frothy emulsion in a few minutes.[^[1037]] Taddei made use of this powder with complete success in the case of a man who had swallowed seven grains of corrosive sublimate by mistake for calomel. Violent symptoms followed the taking of the poison; but they were immediately assuaged by the administration of the antidote; and the person soon got quite well.[^[1038]] It is probable that wheat flour will prove an effectual antidote by reason of the gluten it contains. On agitating for a few seconds a solution of twelve grains of corrosive sublimate along with three ounces of a strong emulsion of flour, and immediately filtering,—I find that ammonia and carbonate of potass have little or no effect, that hydriodate of potass occasions a yellow precipitate, and that the acrid, astringent taste of the solution is removed; whence it may be inferred, that the corrosive sublimate is all decomposed, that little mercury remains in solution, and that what does remain is in the form of a chloride of mercury and gluten.

When neither albumen nor gluten is at hand, milk is a convenient antidote of the same kind.

Iron filings would appear to be also a good antidote. MM. Milne-Edwards and Dumas have found that when they were administered in the dose of an ounce to animals after twelve or eighteen grains of corrosive sublimate had remained long enough in the stomach for the symptoms to begin, the animals recovered from the effects of the poison, and died only some days afterwards of the effects of tying the gullet, which operation was necessary to prevent them vomiting. The iron obviously acts by reducing the corrosive sublimate to the metallic state.[^[1039]]

Meconic acid, the peculiar acid of opium, which will be described under the head of that poison, is also probably a good antidote. Pettenkoffer correctly remarks that this acid has a great tendency to form very insoluble salts with the metallic oxides, particularly with the deutoxides, and above all when the acid is previously in union with a base which constitutes a soluble salt.[^[1040]] On this account it must be a good antidote. Pettenkoffer adds, that the precipitating action of the meconates is the reason why “the operation of corrosive sublimate on the animal body is almost entirely prevented by opium.” Opium, however, cannot be safely used in such quantity as to decompose all the corrosive sublimate in a case of poisoning; for I find that an infusion of thirty-three grains is required to precipitate all which can be thrown down from a solution of five grains of the mercurial salt. I am not aware of any instances on record where poisoning with corrosive sublimate has been prevented or cured by opium given so as to decompose the salt; but a very remarkable case will be related under the head of Compound Poisoning, where the phenomena of its action were masked and altered in a singular manner. There is little doubt that the alkaline meconates must prove valuable antidotes for corrosive sublimate. At present an effectual barrier to their employment is their rarity; but they might be rendered more accessible, as a great quantity of meconate of lime, which is at present put to no use, is formed in the manufacture of muriate of morphia; and meconate of potass may easily be prepared in sufficient quantity from the meconate of lime.

It has been alleged by Dr. Buckler of Baltimore, that a mixture of gold-dust and iron filings is an effectual antidote; but Orfila denies this statement; and the fact if true would be unimportant, on account of the improbability of the materials being ever at hand in practice.[^[1041]]

M. Mialhe suggested not long ago as an antidote the proto-sulphuret of iron prepared by decomposing sulphate of protoxide of iron by hydrosulphate of ammonia; and Orfila found that it is a perfect chemical antidote, which altogether prevents the poisonous action of corrosive sublimate, if administered to animals either before or immediately after the poison; but he further ascertained that the lapse of ten minutes was sufficient to render it of no use.[^[1042]] It is difficult, however, to perceive why in this respect it should differ from white of egg or any other chemical antidote.

As to the old antidotes for poisoning with corrosive sublimate, such as the alkaline carbonates, the alkaline hydrosulphates, cinchona, mercury, charcoal,—Orfila has given them all a fair trial, and found them all inefficacious. It would appear, however, from a case related in a late American journal, that frequent doses of charcoal powder have much effect in soothing the bowels and allaying the inflammation after the poison is evacuated.[^[1043]]

The treatment of mercurial salivation consists in exposure to a cool pure air, nourishing diet, and purgatives, if the intestinal canal is not already irritated. In some of the inflammatory affections it induces, venesection is required; in others it is hurtful. In some complaints induced by mercury, as in iritis, the poison appears to be its own antidote; for nothing checks the inflammation so soon and so certainly as mercurial salivation.

Dr. Finlay of the United States proposed to check mercurial salivation by small doses of tartar emetic frequently repeated, so as to act on the skin;[^[1044]] and Mr. Daniell has recommended large doses of the acetate of lead as an effectual antidote for the same purpose.[^[1045]] I have tried both of these plans several times with apparent success. In one instance particularly, where a severe salivation was threatened by the administration of six grains of calomel in three doses, and where profuse salivation, ulceration of the tongue and swelling of the face actually did commence with violence, the mercurial affection after a few days rapidly receded under the use of large doses of acetate of lead.—Dr. Klose, a German physician, says he has found iodine to possess the property of arresting the effects of mercury on the mouth.[^[1046]] The iodide of potassium is generally acknowledged to be one of the best remedies for eradicating the constitutional infirmities left in many by severe courses of mercury.

A great deal might be said on the treatment of the secondary effects of poisoning with mercury. But a thorough investigation of the subject would lead to such details as would be inconsistent with the other objects of this work.

CHAPTER XV.
OF POISONING WITH COPPER

Poisoning with the salts of copper was not long ago a common accident, in consequence of the metal being much used in the fabrication of vessels for culinary and other domestic purposes, or ignorantly resorted to by confectioners and others to impart a good colour to sweetmeats and preserves. Such accidents have been materially diminished in frequency since the poisonous qualities of the metal, and the circumstances under which it is acted on by articles of food, have become known. Nevertheless they are still frequent enough. The diffusion among the common people of the knowledge of the properties of copper has also naturally led some persons to have recourse to its preparations for the purpose of self-destruction. Poisoning with copper has seldom been caused by the wilful act of another person; for the deep colour of its compounds and their strong disagreeable taste render it a difficult matter to administer them secretly. This, however, though difficult, is not impossible: whatever may be swallowed accidentally, may be also administered secretly. In 1795 a woman Inglis was tried at Aberdeen for administering sulphate of copper with intent to poison; but the charge was not proved.[^[1047]] In 1842 an attempt was made at Béziers in France to poison a young woman by dissolving this salt in her coffee; but the first mouthful caused such a sense of constriction in the throat as to apprize her of something deleterious being present, and she escaped after suffering from soreness of the mouth, vomiting and cramps.[^[1048]] A case of imputed poisoning with sulphate of copper has been related at page [76].

Section I.—Of the Chemical History and Tests of the Preparations of Copper.

Metallic copper has a special red colour, to which it gives its own name. Its specific gravity is nearly 9, its hardness considerable, its tenacity great, its point of fusion about 27° W. or at a full white heat.

It unites with oxygen in two proportions, forming a yellowish-red protoxide, and a peroxide, which, when dry, is brownish-black—when hydrated, azure-blue. It unites also with sulphur in two corresponding proportions, forming a gold-yellow proto-sulphuret, the natural copper-pyrites, and a black bisulphuret, which is formed by sulphuretted-hydrogen in all the solutions of this metal. The peroxide unites with ammonia. The acids all unite with the oxide and form blue or green salts, some of which are soluble, some insoluble. The oxide is frequently mixed with other matters to form various pigments; but in such compounds the union is generally mechanical, not chemical. Of the substances thus formed and existing in nature and the arts the following only require notice here. 1. Mineral green, and other pigments formed with the hydrated oxide. 2. Natural verdigris, or the carbonate. 3. Blue vitriol, or the sulphate. 4. Artificial verdigris, or the mixed acetates.

1. Mineral Green.

The description of this substance and its chemical properties must be introduced with a short account of the tests for the unmixed peroxide. When free of water the peroxide is a brownish-black powder or granular mass, which is usually procured by decomposing nitrate of copper at a low red heat. It is easily known by the solvent power of nitric acid, the blue colour of the filtered solution, and the beautiful deep violet tint communicated to the solution by an excess of ammonia. The last property is considered by chemists the most satisfactory proof of the presence of oxide of copper in a fluid. It is alone quite free of fallacy, and may be applied to all the soluble and also many insoluble compounds of copper, provided they are not mixed with a large proportion of vegetable or animal fluids, in which case the colour is often greenish.

In the case of the peroxide and of copper poisons generally, the process of reduction, which has been applied with such delicacy and precision to arsenical and mercurial poisons, loses all its advantages. The metal remains in the flux, and intimately diffused; so that of its physical qualities the colour only can be estimated, and even that but inaccurately, except in the instance of one compound, verdigris.

The hydrated peroxide of copper, when newly formed and well prepared, has a fine azure-blue colour; but on exposure to a gentle heat, it parts with its water, and becomes the anhydrous peroxide. It is procured by precipitating any of the soluble salts of copper by means of caustic potass. It is at once known by the action of ammonia, which immediately forms with it a deep violet-blue solution.

Mineral green, as already mentioned under the head of Arsenic (p. [223]), was originally an arsenical pigment introduced into the art of colour-making by Scheele, and now sometimes sold in this country by the name of emerald-green. But the mineral green of the colourist now contains no arsenic, being a hydrate of peroxide of copper intimately mixed with a little lime, which is generally carbonated. This variety of mineral-green probably varies a little in composition. Some parcels I have found to contain the lime in the state of carbonate; in others the lime was chiefly caustic.

The best method of determining its nature is to dissolve it in diluted hydrochloric acid, which leaves only a slight cloudiness from accidental impurities; and then to transmit through the filtered solution a stream of sulphuretted hydrogen gas. The copper on boiling is all thrown down in the form of a black bisulphuret, and hydrochlorate of lime remains in solution. The lime is then to be detected by its proper tests, after the solution has been filtered and neutralized (see p. [192]). In general this long process is unnecessary, as the medical jurist may be simply required to say whether the suspected substance contains copper. In that case it is only requisite to subject the substance to the action of ammonia, as if it was hydrated peroxide.

Verditer, another green pigment, the basis of which is always oxide of copper, does not appear to differ essentially in composition from mineral green. The samples I have examined consist of a large proportion of hydrated oxide of copper, and a small proportion of carbonate of lime.

2. Natural Verdigris.

This is a compound of no great importance in a medico-legal point of view. Nevertheless an instance has been lately published in which it was taken for the purpose of committing suicide, and was found abundantly in the stomach.[^[1049]] The carbonate of copper exists naturally in two states. In one form it constitutes the rust of copper, or natural verdigris, and is produced as a powdery crust on metallic copper by long exposure to moist air. It is insipid and insoluble, so that pure water left in vessels incrusted with it does not become poisonous. It dissolves with effervescence in sulphuric acid, and without effervescence in ammonia, forming the usual violet solution. In another form it exists in the mineral kingdom, constituting the chief part of a beautiful ore, malachite, and also a considerable proportion of some blue-copper ores.

3. Blue Vitriol.

Blue vitriol, blue copperas, blue stone, vitriol of copper, as it is variously called in common speech, is the sulphate of copper. In the solid form it constitutes large crystals of a deep blue colour, and an acrid, astringent, metallic taste, efflorescent in dry air, and very soluble in water. Under the action of heat it first loses its water of crystallization without undergoing the watery effusion; then its sulphuric acid is driven off partly unchanged, partly decomposed; and at last the brown peroxide is left behind in a state of considerable purity. If carbonaceous matter be previously mixed with the sulphate, the oxide is decomposed at a low red heat, so that the process of reduction may be performed in a glass tube. For the reasons formerly stated, this process does not constitute a convenient or characteristic test for sulphate of copper. The best mode of ascertaining its nature is to dissolve it, and then to apply the tests for the solution.

There are many excellent tests for copper in solution. But the four following are the most delicate and characteristic,—ammonia, sulphuretted hydrogen, ferro-cyanate of potass, and metallic iron.

1. Ammonia causes a pale azure precipitate, which is redissolved by an excess of the test, forming a deep violet-blue transparent fluid. If the solution is very diluted, there is no previous precipitation; the fluid becomes violet without its transparency being disturbed. This is a perfectly characteristic test of copper, and one of great delicacy.

2. Sulphuretted hydrogen gas causes a dark brownish-black precipitate, the sulphuret of copper. This test is one of very great delicacy; but it is not alone decisive of the presence of copper, since lead, bismuth, mercury, and silver, are similarly affected by it. A method, however, will be presently described, by which the precise nature of the sulphuret may be determined.

The alkaline hydrosulphates, for example the hydrosulphate of ammonia, answer equally well with sulphuretted-hydrogen. The solution of the common liver of sulphur throws down, not a black, but a chestnut precipitate.

3. Ferro-cyanate of potass causes a fine hair-brown precipitate, the ferro-cyanide of copper. This test is also exceedingly delicate and characteristic.

4. A polished rod or plate of metallic iron, held in a solution of sulphate of copper, soon becomes covered with a red powdery crust, which is metallic copper; and ere long the solution is changed in colour from blue to greenish-yellow. The action is simple; the iron merely displaces the copper in the solution, in which a sulphate of iron is consequently formed. This test is characteristic, and even of considerable delicacy. At the same time other substances may cause a reddish encrustation on iron by simply rusting it, so that the test cannot be relied on alone.

The four preceding reagents taken together are amply sufficient to prove the existence of copper in a solution. Three other tests, however, may be here briefly alluded to.

Caustic potass in a solution not too diluted causes a fine azure-blue precipitate, the hydrated peroxide of copper.

Oxide of arsenic, with the previous addition of a few drops of ammonia, causes a fine apple-green or grass-green precipitate, the arsenite of copper. This test, which is both delicate and characteristic, has been already fully considered under the head of Arsenic.

The process by fluid reagents, as hitherto laid down, merely proves the presence of copper, but does not indicate the acid with which the oxide is combined. In order to determine whether it is sulphuric acid, the fluid must also be tested with nitrate of baryta followed by nitric acid: a heavy white precipitate is thus produced, which the excess of nitric acid does not redissolve.

4. Artificial Verdigris.

Artificial verdigris is a common pigment, which is met with in the form either of earth-like masses, or of a light powder of a greenish-blue colour and peculiar disagreeable smell, approaching that of vinegar. Like blue vitriol it has a strong metallic, astringent taste. The effect of heat is peculiar. Some acetic acid is in the first place distilled over; a portion of the acid, however, is decomposed and reduces the oxide; and a low red heat is sufficient to make the outer crust of the verdigris distinctly copper-red, when the material is contained in a glass tube.

Artificial verdigris varies somewhat in composition. Foreign verdigris contains chiefly the hydrated diacetate, with a little carbonate, oxide, and even metallic copper, along with particles of the fruit and fruit-stalks of the grape. British verdigris consists of little else than the hydrated diacetate. It is known by the following characters. Ammonia dissolves it almost entirely, forming a deep violet solution. Diluted sulphuric acid dissolves it, evolving an odour of acetic acid, and forming a solution of sulphate of copper, which may be known by the tests for that salt. Boiling water converts it partly into an insoluble brown powder, which is oxide of copper in union with a small proportion of acetic acid, and partly into a greenish-blue neutral acetate, which is dissolved, and may be known by the four tests for sulphate of copper, and the want of action of nitrate of baryta.

It may be right to notice shortly three other salts of copper, the nitrate, the ammoniacal sulphate, and the muriate. The nitrate forms a violet solution, which is acted on by reagents in the same way as the dissolved acetate, but has not any odour of vinegar. The ammoniacal sulphate [ammoniated copper—ammoniuret of copper], has been occasionally used in medicine. It forms, when solid, small scaly crystals, of an intense violet colour and strong ammoniacal odour; and when dissolved it retains its peculiar colour even though very much diluted.—The muriate of copper has a lively grass-green colour, and is acted on by reagents in the same way as the solution of verdigris.

Of the corrosion of copper by articles of food and drink.—To these observations on the chemical history of copper a few remarks must be added relative to the action of various articles of food or drink upon the metal. Unpleasant accidents have often happened from the use of copper vessels in the preparation of food; and it is therefore necessary for the medical jurist to know the circumstances, so far as they have been investigated, under which the poison may be dissolved.

Dr. Falconer found, that distilled water kept several weeks on a polished plate of copper, neither injured its lustre, nor acquired any taste, nor become coloured with ammonia;[^[1050]] and Drouard afterwards observed, that distilled water, kept for a month on copper filings, did not contain any of the metal.[^[1051]] Eller of Berlin, however, remarked, that water, if it contain a considerable quantity of common salt, as four ounces in five pounds, or a twentieth part, will give slight traces of copper after being boiled in a brass pan; and that if the pan be made of copper, a powder is procured by evaporation, which when treated with acetic acid yields so much as 20 grains of acetate of copper.[^[1052]] But it is a singular circumstance, also observed by the same experimentalist, that if beef of fish be boiled with the usual allowance of salt, and with the addition also of various vegetable substances, the liquid does not yield any copper. This observation has been lately denied by Professor Orfila; who says he found copper deposited on a plate of iron in salt water in which beef had been boiled, and that he also obtained copper from the beef itself.[^[1053]] The quantity thus dissolved, however, must be exceedingly small, if the copper be kept clean and free of oxide; for copper vessels, although they have often been the source of fatal accidents, if carelessly used in the preparation of food, have appeared under careful management to be quite harmless. An excellent practical confirmation of this will be found in Michaelis’s Commentaries. He states, that in the Orphan Hospital of Hallé, the food was in his time prepared in large copper vessels, which were kept remarkably clean; and that out of a population of eight or nine hundred he never heard of any one having suffered from symptoms of poisoning with copper.[^[1054]] Several other saline matters promote the solution of copper in water. Thus Dr. Falconer found that alum has this effect when aided by heat; and probably nitre and Epsom salt possess the same quality.[^[1055]] Their mode of action is not very well known.

It is a common though erroneous idea, that milk, heated or allowed to stand in a copper vessel, becomes impregnated with the metal. Eller has shown, that, on the contrary, if the vessel be well cleaned, milk, tea, coffee, beer, and rain-water, kept in a state of ebullition for two hours, do not contract the slightest impurity from copper;[^[1056]] and the same remark has been also made by Dr. Falconer with respect to cabbage, potatoes, turnips, carrots, onions, rice, and barley.[^[1057]]

But Eller farther remarked, that, if the vessel is not thoroughly clean, then all acid substances dissolve the carbonate that encrusts it, especially if left in it for some time. Nay, it appears that some acid matters, though they do not dissolve clean copper by being merely boiled in it a few minutes, nevertheless, if allowed to cool and stand some time in it, will acquire a sensible impregnation.[^[1058]] Dr. Falconer also observed that syrup of lemons, boiled fifteen minutes in copper or brass pans, did not acquire a sensible impregnation; but if it was allowed to cool and remain in the pans for twenty-four hours, the impregnation was perceptible even to the taste, and was discovered by the test of metallic iron.[^[1059]] This fact has been farther confirmed by the researches of Proust,[^[1060]] who states, that, in preparing food or preserves in copper, it is not till the fluid ceases to cover the metal, and is reduced in temperature, that solution of the metal begins. Inattention to this difference has been the cause of fatal accidents, of which the following case from Wildberg’s Practical Manual will serve as a good example. A servant left some sour-krout for only a couple of hours in a copper pan which had lost the tinning. Her mistress and a daughter, who took the cabbage to dinner, died after twelve hours illness; and Wildberg found the cabbage so strongly impregnated with copper, that it was detected by the test of metallic iron.[^[1061]]

Some wines have the same power, by reason of the acid they contain. Hence Eller found twenty-one grains of the acetate in five pounds of French white wine, after being boiled in a copper vessel. An epidemic disease, mentioned by Fabricius, which broke out in 1592 among the senators of Bern, and a number of their guests who had been invited to a great entertainment, was supposed to have arisen from a poisonous impregnation of this kind. The wine used at the feast had been kept cool in copper vessels immersed in a very cold well. Many of the company were attacked with dysenteric symptoms, and some died.[^[1062]]

Vinegar also dissolves metallic copper. Dupuytren observed that the vinegar sold by hawkers in the streets of Paris generally contained copper from the action of the acetic acid on the stop-cocks of the little vessels used in retailing it.[^[1063]] Others in like manner have found copper in vinegar pickles prepared in copper vessels. Thus Dr. Percival found a strong impregnation of copper in pickled samphire, of which a young lady ate one morning two breakfast platefuls, and which proved fatal to her in nine days.[^[1064]] And Dr. Falconer once detected so large a quantity in some pickled cucumbers bought at a great London grocer’s, that it was deposited on a plate of iron, and imparted its peculiar taste and smell to the pickles.[^[1065]] It seems indeed to have been at one time the custom to make a point of adulterating pickles with copper; for in many old cookery-books the cook is told to make her pickles in a copper pan, or to put some halfpence among the pickles to give them a fine green colour.[^[1066]]

The action of the vegetable acids, and more particularly of vinegar on copper, depends on the co-operation of the atmospheric air held in solution by the fluid, and in contact with its surface. Without such co-operation the copper cannot be oxidated. This fact, which was determined experimentally by Proust,[^[1067]] will explain the observations of Eller and Falconer,—that it is not dangerous to boil acidulous liquids in copper vessels, while it is very unsafe to keep these fluids cold in the same vessels. In the latter instance the liquid is impregnated with atmospheric air, while in the former the usual aëriform contents are driven off by the heat. I must observe, however, in limitation of Proust’s statement, that strong vinegar, such as the pyroligneous acetic acid, will become impregnated to a certain extent if boiled in copper vessels. The action which takes place is the same as that remarked by him in the case of cold vinegar:[^[1067]] the copper where it is always covered remains quite bright; but at the edge of the fluid it becomes oxidated, and the oxide is dissolved by the occasional bubbling up of the acid.

In the last place, the property of oxidating and uniting with copper is likewise possessed by fatty matters and oils. According to Falconer, fatty substances do not act on metallic copper unless they are rancid.[^[1068]] But Proust is probably more correct when he states, that they will act, though fresh, provided they are aided by the co-operation of atmospheric air.[^[1069]] I have found, that, if a plate of copper be thrust into a mass of fresh butter, its surface becomes dark in twenty-four hours, and the butter becomes green wherever it is in contact both with the copper and the air, but not where it covers the metal closely. In fresh hog’s lard, however, I have found that the whole lard in contact with the copper becomes blue even at a depth to which the air can scarcely reach. The action of oils is similar. It is even probable that they act when hot; for Mr. Travis found that hot oil became green when kept for only four or five minutes in a copper vessel.[^[1070]] Dr. Falconer mentions that the property of acting on copper is possessed in an eminent degree by volatile oils, and especially by oil of cloves and oil of cinnamon.[^[1071]]

The general result of the preceding observations is, that there is hardly any article of food or drink which may not become impregnated with copper if kept in copper vessels, as there are few articles which do not contain either an acid or some fatty matter; and it farther appears, that the impregnation will scarcely ever take place during the boiling of such articles, but only during the preservation of them in a cold state. It must also be considered, that, independently of these chemical impregnations, articles of food may be mixed mechanically with copper, in consequence of the vessels being allowed, through the carelessness of the cook, to become covered with rust or carbonate, which is subsequently removed by the friction of the solid parts of any article that is boiled in them.

In order to prevent accidental impregnations, copper vessels are usually tinned. The tinning consists of an alloy of tin and lead, which is much less easily attacked than the copper, and the safety of which is farther insured by the circumstance, that the substances endowed with the property of dissolving lead, cannot attack that metal before the whole tin of the alloy is oxidated.[^[1072]] The tinning of copper, however, has been found to be but a partial protection, as the tinning is apt to be worn away without attracting the attention of servants. Hence the use of copper in the fabrication of kitchen utensils is becoming every day more and more limited, especially since the manufacture of cast-iron vessels was brought to perfection in this country.

Many instances might be adduced of the ignorance and carelessness which prevailed, even not far back in the last century, as to the employment of copper vessels for culinary purposes. In addition to the instances already quoted, the following are well deserving of notice. Gmelin was consulted by the abbot of a monastery, on account of a violent disease which prevailed throughout the whole brotherhood of monks. The symptoms were obstinate and severe colic, retching and bilious vomiting, costiveness, flatus, burning pain in the pit of the stomach, under the sternum, in the kidneys and extremities, and paralytic weakness in the arms. On inquiring into the cause of this singular combination of symptoms, Gmelin found that every vessel in the kitchen, the pots and pans, and even the milk pails and butter dishes for storing the butter, were made of copper.[^[1073]] In 1781 an establishment of Jacobin monks at Paris were all violently affected from a similar error. The cook on a Friday and the subsequent Saturday, after boiling fish for the dinner of the monks in a copper pan, and drawing off the water, poured vinegar over the fish, and left it thus in the pan for a considerable time. On the evening of Friday several of them were taken severely ill with headache, acute pain in the stomach and bowels, precordial anxiety, purging, great feebleness, and cramps in the legs. The rest of them, to the number of twenty-one in all, were similarly attacked next morning; and the symptoms continued in most of them for five or six days.[^[1074]]

A singular variety of adulteration with copper was brought not long ago into public notice on the continent,—namely, the impregnation of bread with the sulphate of copper, which was used in small quantity for promoting the fermentation of the dough. This practice was first detected in some of the towns of Flanders, but was afterwards found to prevail in France.[^[1075]] Some chemists of reputation have indeed doubted altogether the existence of the practice; and M. Barruel in particular, who was consulted on the subject by the Prefecture of Paris, publicly declared his disbelief, because he remarked that, instead of favouring the panary fermentation, a very small proportion of sulphate of copper actually impeded it, and besides gave the bread a greenish colour of such depth that no customer would take it for a wholesome article.[^[1076]] Subsequent inquiries, however, have shown that Barruel must have allowed himself to be misled, probably by using too much of the sulphate of copper. For the bakers of St. Omer admitted that they practised this ulceration for the sake of saving their yeast, the proportion required being an ounce of the salt in two pints of water, for every hundred weight (quintal) of dough, or about an 1800th part.[^[1077]] And it appears from an interesting set of experiments by M. Meylink, a chemist of Deventer, that, contrary to the statements of Barruel, sulphate of copper not only possesses the property of promoting the panary fermentation, but likewise constitutes in several important respects a source of adulteration, which ought to be prohibited and strictly looked after. He found that when he added to half a Flemish pound of dough from one grain to eight grains of sulphate of copper, fermentation took place more quickly than in the same dough without such addition, and nearly in proportion to the quantity of the salt used;—that the adulterated loaves when taken out of the oven were much better raised, and the loaf with only one grain of the salt likewise much whiter, than those which were not adulterated;—that a slight increase, however, in the proportion rendered the loaf greenish, and gave it a peculiar taste; but especially that the employment of the salt of copper even in the small proportion of one grain had the singular effect of bringing about the complete fermentation of the dough with considerably less loss of weight than occurs in the common process of baking, the loss in the sound and in the adulterated loaves being in the proportion of 116 to 100.[^[1078]] It certainly seems fully proved, then, that the adulteration of bread with sulphate of copper is an important fraud in more ways than one. Some doubt may be entertained whether any injury can result to the human body from even the habitual use of so small a quantity as that employed by the bakers; and at all events, we may be satisfied that if any bad effects do result, this can only happen from the continual use of the adulterated bread for a great length of time. But there can be no doubt that the practice is a fraud on the public, by enabling the baker to make his loaves of the standard weight with a less allowance of nutritive material.

Another important adulteration also indicated by foreign chemists, is that of syrup made with the coarsest kinds of sugar, and decolorized by means of sulphate of copper. The colour is removed by adding a solution of the sulphate to the syrup boiling hot, and decomposing the salt by lime; but a portion of the salt is often left behind, and in consequence accidents have arisen from such syrups being used in making various medicinal preparations.[^[1079]]

Of the detection of copper in organic mixtures.—As in the instance of arsenic and mercury, so in that of copper the presence of vegetable and animal principles interposes material obstacles in the application of the ordinary tests and methods of analysis. Some substances, such as albumen, milk, tea, coffee, and the like, decompose the solutions of the salts of copper, throwing down the oxide of copper in union with various proximate principles. Others, such as red wine, bile, vomited matter, and the tissues composing the stomach, although they do not decompose the soluble copper salts, alter materially the action of reagents on them. These facts were established long ago by Professor Orfila;[^[1080]] and various processes were suggested by him, by myself in former editions of this work, and by various other authors, with the view of overcoming the difficulties in question.

More lately a fresh difficulty has been started, which has been thought to render every prior process fallacious, including that which I have proposed. For it is alleged that copper exists naturally as a constituent part of many vegetable and animal substances, and more especially in the organs of the human body. This statement is so important as to deserve attentive consideration before fixing on a method of analysis for medico-legal cases.

Some time ago Meissner pointed out the existence of a trace of copper in some vegetable substances;[^[1081]] and more recently M. Sarzeau alleged that a minute quantity of this metal, sometimes not above a 1,500,000th and never exceeding a 120,000th part, may be detected not only in all vegetable substances, but likewise in the blood, as well as other fluids and solids of the animal body. Among vegetable substances he examined with great care cinchona-bark, madder, coffee, wheat and flour; and he succeeded in separating metallic copper from them all.[^[1082]]

The accuracy of these researches was called in question. By some chemists the discoveries of Meissner and Sarzeau were confirmed so far as they relate to vegetable substances. By others the confirmation was extended to the animal body, and more especially to the human organs and secretions. Thus M. Devergie says, that, having been struck with the singular circumstance of two cases occurring to him in a single year, where analysis indicated copper in the tissues of the alimentary canal of persons suspected of having died of poison, he was led to inquire, along with M. O. Henry, whether the metal was contained naturally in the textures of the human body; and that in the course of many experiments, although unable to detect any in a solution made by means of weak acetic acid, he could always find it by the process of incineration.[^[1083]] Orfila has also repeatedly detected traces of copper in the bodies of animals not poisoned with the preparations of that metal.[^[1084]]

By other experimentalists opposite results have been obtained, more especially in regard to animal solids and fluids. In the course of an inquiry relative to the question, whether poisons pass into the blood, I failed to detect copper in the blood, muscles, or spinal marrow of animals, although the method of analysis must have enabled me to discover extremely minute quantities of that metal. Afterwards M. Chevreul was unable to detect the slightest trace of copper in beef, veal, or mutton; nor was he more successful in the case of wheat, provided care was taken to keep the sample clean.[^[1085]] And more recently MM. Flandin and Danger have denied that there is any copper ever found naturally in the body.[^[1086]]

These discrepant results appear to be in a great measure reconciled in an extensive inquiry into the subject by M. Boutigny; who found that wheat, wine, cider, and some other substances of a vegetable nature, do frequently present minute traces of copper, but only when copper is contained in the manure used in raising the grain, apples, and the like; that manure from the streets of great towns always contains copper, and introduces it into vegetable articles grown where such manure is used; and that the occasional presence of the same metal in animal substances may be traced either to copper vessels having been employed in preparing or preserving them, or to the animals producing them having been fed on vegetables presenting from the causes mentioned above a faint cupreous impregnation.[^[1087]]—Another fallacy, which may account for the alleged invariable success of some chemists, has been pointed out by M. Hiers-Reynaert of Bruges. Having once obtained copper in a specimen of suspected bread, when he used paper for a filter, but none when he used linen, he was led to examine various filtering papers, and found that some kinds contain an appreciable trace of copper.[^[1088]] This important fact must be attended to in all medico-legal investigations.

On the whole, whatever may be thought of the physiological question, whether copper forms a constituent of the textures and fluids of vegetables and animals, it seems well established that this metal is often present there in minute proportion; and consequently its possible presence must not be overlooked in medico-legal researches. Fortunately methods of analysis are known which this source of fallacy does not affect.

Process. The following method embraces all possible cases; and it is exempt, so far as yet appears, from every source of error.

1. Should the subject of analysis not be a liquid, render it such by dividing it into small fragments, and boiling it gently for an hour in distilled water acidulated with acetic acid, which must previously be ascertained not to contain any copper. If the liquid be not viscid, filter it at once; but if it be too viscid for filtration, pass it through a muslin sieve, add two volumes of rectified spirit to it when cool, and then filter it. Transmit through a small portion of it a stream of hydrosulphuric acid gas; and if a brownish-black precipitate or cloud form, subject the whole liquid to the gas. A brown precipitate, which is sulphuret of copper, will separate either immediately, or after ebullition and repose for an hour. Collect the precipitate, if abundant, by filtration, if scanty, by repeated subsidence and affusion. Dry it, subject it to a low red heat, and then heat it with a little strong nitric acid, which will convert the sulphuret into the sulphate of copper. This salt, dissolved out by boiling distilled water, may be subjected to the tests described above, and especially to ammonia.

2. If the copper be extremely minute in quantity, sulphuretted hydrogen will not act upon it in a fluid much charged with organic matter. To meet this possible case, which may occur when the subject of analysis is an organ of the human body into which the poison has been conveyed by absorption,—let the liquid be evaporated to dryness, and charred in the following manner. Heat in a porcelain basin a quantity of nitric acid equal in weight to the residuum, together with a fifteenth of chlorate of potash. Add the dry residuum in successive portions of such magnitude as not to occasion too great effervescence. When it has been all added, heat the product till it become dark-red and thick. It will then, or soon afterwards, begin suddenly to char, and at length a thick vapour will arise in dense clouds; upon which, the charring being complete, the heat must be withdrawn. Pulverise the carbonaceous mass; boil it with nitric acid diluted with its own volume of water; and evaporate the filtered fluid to dryness, so as to expel any excess of acid. Dissolve the saline residuum, and test the solution with the usual reagents.

The first branch of this process is nearly the same with the one adopted in the last edition of the present work. The second is derived from a process lately proposed by Orfila.[^[1089]]

The principles on which it is founded are these. 1. Of the numerous organic compounds formed by vegetable and animal principles with the salts of copper, all either dissolve in very weak acetic acid, or part with their oxide of copper to it. This was pointed out by me in my last edition. 2, Weak acetic acid, as already mentioned (p. [356]), has been shown by M. Devergie to be incapable of dissolving that copper which is contained naturally in the tissues, at least so as to render it discoverable by the subsequent steps of the process. 3, According to Orfila, copper naturally present in organic substances, is never indicated by the second branch of the process, provided the charred product of the action of nitric acid and chlorate of potash be not heated to incineration. It does not appear why the charring process, when so conducted, should separate adventitious copper, and not that which is present naturally. But the empirical fact may be accepted in the mean time, as it rests on apparently careful experiments.

Orfila does not use acetic acid in the first branch of his process, but merely infuses the suspected matter in cold water, and if copper be not thus found, he has recourse to boiling water. But this method introduces needless complexity; and besides neither maceration, nor boiling with mere water, will dissolve out the whole oxide of copper. Acidulation with acetic acid dissolves it all; and Devergie has shown that this advantage is gained without any additional fallacy arising from the possible presence of copper as a natural ingredient of the substance under examination (p. [356]).

Section II.—Of the Action of Copper, and the Symptoms it excites in Man.

The symptoms caused by copper have at least two varieties in their character. One class arises from its local action on the alimentary canal; the other from its operation on distant organs.

This double influence is proved by the experiments of Drouard on animals, published in his inaugural dissertation at Paris in 1802; and by those of Orfila in his Toxicology.

When Drouard gave twelve grains of verdigris to a strong dog fasting, he observed that it caused aversion to food, efforts to vomit, diarrhœa, listlessness, and death in twenty-two hours; and that the stomach was but little inflamed. When two grains dissolved in water were injected into the jugular vein of another dog, it caused vomiting and discharge of fæces in seven minutes, then rattling in the throat, and death in half an hour; and there was no particular morbid appearance in the body.—Half a grain killed another in four days; and in addition to the preceding symptoms, there was palsy of the hind legs for a day before death. Six grains of the sulphate introduced into the stomach killed a dog in half an hour, without producing any appearance of inflammation.[^[1090]]

These experiments prove that it is not by causing local irritation that this poison proves fatal. But its mode of action is more distinctly shown in the later and more accurate experiments of Orfila. He found that twelve or fifteen grains of the neutral acetate generally killed dogs within an hour; and that besides the usual symptoms of irritation in the stomach, they often had insensibility, almost always convulsions, and immediately before death rigidity, or even absolute tetanus. He likewise remarked violent convulsions and insensibility when a grain of this salt was injected into the veins; and death was then seldom delayed beyond ten minutes. In no case was there any particular morbid appearance, except loss of contractility in the voluntary muscles.[^[1091]] More recently results nearly the same have been obtained by Mitscherlich; and when doses of two drachms of sulphate of copper were given, he observed after death pale blueness of the villous coat of the stomach, mingled with brownness,—the apparent effect of chemical action.[^[1092]]

Allied to these results are those obtained by my late colleague, Dr. Duncan, and by Mitscherlich, when the sulphate was applied to a wound. Dr. Duncan observed that death took place in twenty-two hours, and the body was every where in a healthy state. Mitscherlich found that a drachm of either sulphate or acetate proved fatal in four hours, with symptoms of extreme prostration. The experiments of M. Smith, repeated by Orfila, are at variance with these; for one or two drachms of the acetate applied to a wound in the thigh of a dog caused only local inflammation, and no constitutional symptoms.[^[1093]]

It follows from the researches now detailed, that the salts of copper act in whatever way they are introduced into the system, and the more energetically, the more directly they enter the blood. The inquiries of Mr. Blake farther show, that when injected into the blood-vessels, they act with peculiar force in exhausting muscular irritability, and occasion death by paralysing the heart if they are injected into a vein. Six grains of the sulphate injected into the jugular vein of a dog reduced the force of the heart’s contractions, and fifteen grains arrested them in twelve seconds, leaving in the dead body distension of the heart, loss of contractility, and florid blood in the left cavities. Ten grains injected into the aorta through the axillary artery caused no sign of obstruction in the capillary system; and small doses of three or four grains occasioned vomiting, dyspnœa, and stiffness of the limbs; and immediately after death the muscles had lost their irritability.[^[1094]]

Copper has been sought for, with variable success, in the blood of animals poisoned with its salts. Drouard was unable to detect it in the blood. But this need not excite surprise, because the same physiologist could not detect it, even when he had injected it into a vein.—Lebküchner, who published a thesis at Tübingen in 1819, on the permeability of the living membranes, succeeded in discovering it. He introduced four grains of the ammoniacal sulphate into the bronchial tubes of a cat, and five minutes afterwards, when the animal was under the action of the poison, he drew some blood from the carotid artery and jugular vein; and he detected copper in the serum of the former, but not in the latter, by sulphuretted-hydrogen and hydrosulphate of ammonia.[^[1095]]—Afterwards Dr. Wibmer of Munich also succeeded in discovering it. In a dog which had taken from four to twenty grains of the neutral acetate daily for several weeks, he found the metal in the substance of the liver, but not anywhere else. In the charcoally matter left by incinerating the liver, nitric acid formed a solution, which when neutralized gave the characteristic action of the salts of copper with sulphuretted-hydrogen, ferro-cyanate of potash, and ammonia.[^[1096]] Fischer also found copper in the blood of a dog which in forty-three days had got gradually-increasing doses of acetate of copper, till at length twelve grains were taken daily.[^[1097]] Orfila has recently often detected copper in the liver, spleen, heart, kidneys, and lungs of animals poisoned with its salts.[^[1098]] These facts are not all invalidated by the late discovery of the presence of copper in the animal tissues of men and animals not poisoned with its preparations. For in the experiments of Wibmer and of Orfila the quantity found in cases of poisoning was much larger than in the ordinary state of things; and the poison was accumulated in particular organs, especially the liver. The absorption of copper may therefore be considered as fully substantiated; and it is equally important whether it be regarded as a physiological or medico-legal fact.

Dr. Duncan’s experiment on its effect when applied to a wound shows that it may prove fatal when applied externally. Yet in small quantities, the sulphate is daily used with safety for dressing ulcers.

As to the preparations of copper which are poisonous, it is pretty certain that, like all other metals, it is not deleterious unless oxidated, and that its soluble salts are by far the most energetic. Portal, indeed, has related the case of a woman who, while taking from a half a grain to four grains of copper filings daily, was seized with symptoms of poisoning.[^[1099]] But it is probable the filings were oxidated; for Drouard gave an ounce to dogs without injuring them at all,[^[1100]] and Lefortier more lately observed that two drachms had no effect.[^[1101]] The same explanation must be given of the injury sustained by those artisans who prepare and use what is called “bronze dust” in printing and paper-staining. If the substance employed be nothing else than an alloy of copper and zinc, as is alleged, the injurious effects to be mentioned presently can only be explained on the supposition that the copper becomes oxidated either before or after coming in contact with the body. It deserves to be added, that many persons have swallowed copper coins and retained them for weeks without having any symptoms of poisoning.

The sulphuret is equally innocuous with the metal if pure; but it appears probable that it becomes oxidated by long exposure to the air, and passes into the state of sulphate. Orfila found that an ounce of recently prepared sulphuret had no effect on a dog; but half an ounce of a parcel which had been long kept caused vomiting, and yielded a little sulphate to water.[^[1102]] The power of the oxides has not been ascertained. They are certainly poisonous; and Lefortier found that both the red dioxide and black protoxide undergo solution in no long time in the stomachs of dogs.[^[1103]] The hydrated protoxide is probably more active. From some experiments made at the hospital of St. Louis in Paris, it appears that twelve grains will cause nausea, pain in the stomach and bowels, vomiting and diarrhœa.[^[1104]] There is no doubt that the carbonate or natural verdigris, the phosphate, and even the subphosphate, though quite insoluble in water, are capable of acting as poisons, because Lefortier found that they are soon dissolved in the stomachs of dogs, and in small doses cause severe vomiting in the course of fifteen minutes.[^[1105]] But it is chiefly in the soluble salts that we are to look for the full development of the action of this poison. A very small quantity of the sulphate will prove fatal; for, as already noticed, Drouard found that six grains killed a dog in half an hour.

The symptoms caused by the soluble salts of copper in man are, in a general point of view, the same with those caused by arsenic and corrosive sublimate. But there are likewise some peculiarities. According to the cases related by Orfila in his Toxicology, the first symptom is violent headache, then vomiting and cutting pains in the bowels, and afterwards cramps in the legs and pains in the thighs. Sometimes throughout the whole course of the symptoms there is a peculiar coppery taste in the mouth, and a singular aversion to the smell of copper. Drouard notices this in his thesis; and says, that, having himself been once poisoned with verdigris, the smell of copper used to excite nausea for a long time after.[^[1106]] Another symptom, which occasionally occurs in this kind of poisoning, and never, so far as I know, in poisoning with arsenic or corrosive sublimate, is jaundice. It likewise appears that, when the case ends fatally, convulsions and insensibility generally precede death.

A set of cases illustrating the slighter forms of poisoning with copper has been published by M. Bonjean of Chambéry. The cause was the preparation of an acid confection in a copper vessel. Two women suffered from severe headache, constriction of the throat, nausea, colic, and extreme weakness. Two young men, who had eaten the confection more freely, had for some hours excruciating colic, severe pain in the mouth and throat, impeded breathing, and hurried irregular pulse; and for twenty-four hours they suffered severely from headache and prostration of strength.[^[1107]]

The following case communicated to Professor Orfila by one of his friends will convey a good idea of the symptoms in severe cases, which do not prove fatal. A jeweller’s workman swallowed intentionally half an ounce of verdigris, suspended in water. In fifteen minutes he was attacked with colic pains and profuse vomiting and purging. When seen by the physician eight hours afterwards there was not much vomiting, but frequent eructation of a matter containing verdigris, some salivation, a small pulse, and blueness about the eyes. In sixteen hours jaundice began to appear. In the course of the night he was a good deal relieved from the colic pains by three alvine discharges; and next morning he had ceased to vomit, and the pain had disappeared. But he complained of a taste of copper in his mouth, and the jaundice had increased. From this time he recovered rapidly, and on the fourth day convalescence was confirmed.[^[1108]]

When the poisoning ends fatally, convulsions, palsy, and insensibility, the signs in short of some injury done to the brain, are very generally present. This is illustrated by a good example in Pyl’s Essays and Observations. It was the case of a confectioner’s daughter, who took two ounces of verdigris, and died on the third day under incessant vomiting and diarrhœa, attended towards the close with convulsions, and then with palsy of the limbs. This case, however, is chiefly valuable for the dissection, which will be noticed presently.[^[1109]] But two cases of the same description are related in greater detail by Wildberg in his Practical Manual, which clearly show the action of this poison on the brain. They are the cases formerly alluded to of a lady and her daughter who were poisoned by sour-krout kept in a copper pan. Soon after dinner they were attacked first with pain in the stomach, then with nausea and anxiety, and next with eructation and vomiting of a green, bitter, sour, astringent matter. The pain afterwards shot downwards throughout the belly, and was then followed by diarrhœa; afterwards by convulsions, at first transient, then continued; and finally by insensibility. The daughter died in twelve hours, the mother an hour later.[^[1110]] In these three cases, although there was not any jaundice noticed during life, the skin was very yellow after death.—In some instances it would appear that narcotic symptoms form the commencement and irritant symptoms the termination of the poisoning. This unusual relation occurs in a case of recovery related by M. Julia-Fontenelle, and also, though less remarkably, in a fatal case mentioned by Wibmer. The subject of the former was a man who intentionally took a solution of copper in vinegar, prepared by keeping several sous-pieces seven days in that fluid. In three hours he was found in a state of insensibility, with the jaws locked, the muscles rigid and frequently convulsed, the breathing interrupted, and the pulse small and slow. In half an hour he was so far roused that he could tell what he had done; and soon after taking white of eggs the convulsions ceased: but next day the belly was hard and tender, and the repeated application of leeches was required to subdue the abdominal irritation that ensued.[^[1111]] In the fatal case by Wibmer, that of a girl of 18, who was poisoned by a dish of beans having been cooked in a copper vessel, sickness, pain of the belly and vomiting speedily arose, but were soon followed by convulsions and loss of consciousness. Next day there was little pain, but extraordinary paralytic weakness of the arms and legs: the abdomen afterwards became distended and painful; and death took place in seventy-eight hours.[^[1112]]—A case where convulsions were produced by two drachms of blue vitriol is mentioned by Dr. Percival.[^[1113]]—In other instances it would appear that no nervous affection occurs at all, as in the case of a young lady related by Percival, who, when poisoned with pickled samphire containing copper, suffered chiefly from pains in the stomach, an eruption over the breast, general shooting pains, thirst, a frequent small pulse, vomiting, hiccup, and purging. Death occurred on the ninth day, without stupor or convulsions.[^[1114]]

Besides these effects when introduced in considerable doses and in the form of soluble salts, copper is said to produce other disorders when applied to the body for a long time in minute quantities and in its metallic or oxidized state. Among those artisans who work much with copper various affections are thought to be gradually engendered by merely handling the metal. Patissier in his treatise on the diseases of artisans says, that copper-workers have a peculiar appearance which distinguishes them from other tradesmen,—that they have a greenish complexion,—that the same colour tinges their eyes, tongue, and hair, their excretions, and even their clothes through the medium of the perspiration,—that they are spare, short in stature, bent, their offspring ricketty, and they themselves old and even decrepit at their fortieth or fiftieth year.[^[1115]] Mérat also asserts that they are liable to the painters’ colic, that peculiar disease soon to be noticed as a common effect of the long-continued application of lead.[^[1116]]

But these notions must be received with some limitation. At least the alleged effects on copper-workers are by no means invariable. For copper-workers now-a days in this country and elsewhere are by no means the unhealthy persons Patissier represents them to be. As to colica pictonum, it is very rare among them; and possibly the cases noticed by Mérat might have been produced by the secret introduction of lead into the body, if indeed they were not cases of common colic.

A very singular set of cases was lately brought under notice by Mr. Gurney Turner, where poisoning seemed to have been occasioned by the external application or inhalation of the fine dust used for imitating gilding by painters, paper-stainers, and porcelain-painters, and which is said to be essentially brass in a state of fine division. The workmen who use it, are very apt to be attacked with irritation about the private parts, and a vesicular eruption about the hairs on the pubes,—with loss of appetite, tendency to vomiting, and other symptoms of irritation in the stomach,—with obstinate constipation,—with soreness and dryness of the throat and irritation in the nose,—and with want of sleep, and a remarkable greenness of the hair over the whole body.[^[1117]]

Section III.—Of the Morbid Appearances caused by Copper.

The appearances found in the body after death by poisoning with copper are chiefly the signs of inflammation.

Where death takes place very rapidly, however, it is probable, that no diseased appearance whatever will be perceptible. At least this was the case in the animals experimented on by Drouard and Orfila; and little doubt can therefore be entertained that the result would be the same with man also in similar circumstances.

When death ensues more slowly, as in the only fatal cases yet on record of its action on man, the marks of inflammation coincide with the signs of irritation during life. The best account I have seen of the morbid appearances under such circumstances is in the cases related by Pyl, by Wildberg, by Wibmer, and by Dégrange.

In Pyl’s case the whole skin was yellow. The intestines, particularly the lesser intestines, were of an unusual green colour, inflamed, and here and there gangrenous. The stomach was also green; its inner coat was excessively inflamed; and near the pylorus there was a spot as big as a crown, where the villous coat was thick, hard, and covered with firmly adhering verdigris. The lungs are likewise said to have been inflamed. The blood was firmly coagulated.

In the cases related by Wildberg, which are very like each other, the skin on various parts, and particularly on the face, was yellow, but on the depending parts livid. The outer coat of the stomach and intestines was here and there inflamed; and the inner coat of the former was very much inflamed, and even gangrenous[^[1118]] near the pylorus and cardia. The duodenum and jejunum, and likewise the gullet, were in a similar state. The blood in the heart and great vessels was black and fluid.

In the case of the girl referred to by Wibmer, the skin was ochre-yellow, the stomach green, much inflamed, especially near the pylorus, the gullet and intestines also inflamed, the diaphragm red, the brain healthy, the lungs and heart “gorged with thick blood.”

In the case of poisoning with carbonate of copper described by Dégrange [p. [348]], in which, however, it is probable that death was accelerated by a fall, there was found congestion of the surface of the brain, arborescent redness of the gullet and a green sand over its surface, general greenness of the villous coat of the stomach, with vascularity of the fundus and points of superficial ulceration, greenness of the whole intestines, with black vascular ecchymosed spots and softening, except in the ileum, and redness of the inner surface of the heart. Copper was detected in the contents of the stomach and intestines.

The intestines have been found perforated by ulceration, and their contents thrown out into the sac of the peritonæum. Portal has related one case where the small intestines were perforated, and several where the perforation was in the rectum, which portion of the intestines, as well as the duodenum, jejunum, and ileum, was also extensively ulcerated.[^[1119]]

The existence of verdigris in the form of powder lining the inside of the stomach after incessant vomiting for three days, is of course an important circumstance in the inspection of the body. But too much reliance ought not to be placed on mere bluish or greenish colouring of the membranes. For Orfila[^[1120]] and Guersent[^[1121]] have both observed, that the inside of the stomach as well as its contents may acquire these tints in a remarkable degree in consequence of natural disease.

Section IV.—Of the Treatment of Poisoning with Copper.

The treatment of poisoning with the salts of copper has been examined in relation to the antidotes by M. Drouard, M. Marcelin-Duval, Professor Orfila, and M. Postel.

The alkaline sulphurets were at one time thought to be antidotes for the poisons of copper, but without any reason. Drouard found that fifteen grains of verdigris killed a dog in thirty hours, notwithstanding the free use of the liver of sulphur.[^[1122]]

Afterwards M. Marcelin-Duval was led from his experiments to infer that sugar was an antidote,[^[1123]] and in the first editions of his Toxicology Professor Orfila agreed with him, and related some experiments of his own, which, along with those of Duval, seemed to place the fact beyond all doubt. Later and more careful experiments, however, satisfied Orfila, that it only acts as an emollient after the poison has been removed from the stomach, and that it has no effect at all if the poison is retained by a ligature in the gullet.[^[1124]] Sugar being thus rejected as well as the sulphurets, he was led to try the effects of albumen; and his experiments induced him to recommend that substance as an antidote in preference to every thing else. He found that the white of six eggs completely neutralized the activity of between 25 and 36 grains of verdigris; so that even when the mixture was retained in the stomach by a ligature on the gullet no effect ensued which could be ascribed to the poison. He infers that white of egg is the best antidote for poisoning with copper.[^[1125]] He likewise found the ferro-cyanate of potass not inferior.[^[1126]]

Since the publication of these inquires the subject has been again examined by M. Postel, who reverts to the original proposition of Duval, that sugar is really a good antidote; and he rests this conclusion partly on direct comparative experiments, showing that it is at least equally effective with white of egg, and partly on the singular fact ascertained by him, that sugar, which was believed to decompose the salts of copper only at the temperature of 212°, does actually accomplish this decomposition at the temperature of the human body, and throws down the copper in the form of oxide.[^[1127]]

According to the experiments of MM. Milne-Edwards and Dumas, metallic iron is likewise a good antidote: they found that when fifteen, twenty, and even fifty grains of sulphate of copper, acetate of copper, or verdigris, were given to animals, and an ounce of iron filings administered either immediately before, or immediately afterwards,—the gullet being tied to prevent the discharge of the poison,—death did not ensue for five, six, or even eight days, and consequently proceeded from the operation on the gullet; and that in one experiment, on the ligature being removed from the gullet, the opening healed up, and complete recovery took place.[^[1128]]

Before quitting the subject of the treatment, it is necessary to caution the practitioner particularly against the employment of vinegar,—a substance often ignorantly used for this, in common with many other, species of poisoning. On account of its solvent power over the insoluble compounds formed by the salts of copper with animal and vegetable matters, it must be injurious rather than useful.

CHAPTER XVI.
OF POISONING WITH ANTIMONY.

The fourth genus of the metallic irritants includes the preparations of antimony. Poisoning with antimonial preparations is not common. They are employed extensively in medicine, however, and consequently accidents have sometimes occurred with them. One of them is also often foolishly used, in the way of amusement, to cause sickness and purging, and likewise to detect servants who are suspected of making free with their mistress’s tea-box or whisky-bottle; and in both of these ways alarming effects have sometimes been produced. In 1837 a woman was tried in England for attempting to poison a child with tartar-emetic; but the poison appeared to have been given through ignorance.[^[1129]] In large doses some of the antimonial compounds may cause death; and one of them, the chloride of antimony, now very little used in this country, is a violent corrosive.

Section I.—Of the Chemical History and Tests for the preparations of Antimony.

Metallic antimony has a bluish-white colour, not liable to tarnish. Its specific gravity is 6·7. It is easily fused, but is not very volatile. In certain circumstances, however, it easily undergoes a spurious sublimation, by being carried along with gases disengaged while it is in the act of being reduced.

A great number of preparations of antimony were at one time to be found in the shop of the apothecary; but they are now reduced to a few. Those which require notice here are the oxide, chloride, and tartar-emetic.

The oxide [sesquioxide] is a white heavy powder, which is best known by its solubility in tartaric acid, and the effects of the tests for tartar-emetic on the solution.

The chloride [sesquichloride], as usually seen, is a yellow or reddish liquid, but when pure is colourless. It is highly corrosive. It is readily known by the effect of water in decomposing it,—an insoluble white subchloride being thrown down, and hydrochloric acid remaining in solution. The latter is detected by nitrate of silver; and the precipitate is known by being soluble in a solution of tartaric acid, and then presenting the reactions of tartar-emetic.

Tartar-Emetic.

In its solid state tartar-emetic forms regular tetraedral or more generally octaedral crystals, which are colourless when pure, efflorescent, and of a slightly metallic taste. As commonly seen in the shops it is in the form of a white, or pale yellowish-white powder.

When heated it decrepitates and then chars; and if the heat be increased the oxide of antimony is reduced by the carbonaceous matter, and little globules appear, like those of quicksilver in point of colour. The best way of reducing tartar-emetic is to char it in a porcelain vessel or watch-glass, and then to increase the heat till the charred mass takes fire. Or the charred mass may be introduced into a tube and heated strongly with the blowpipe, after which globules of antimony will be found lining the bottom of the glass where the material has been. None of it is ever sublimed. It is not easy to procure distinct globules by heating tartar-emetic at once in a small tube.

According to Dr. Duncan, tartar-emetic is soluble in three parts of boiling and fifteen of temperate water. The solution presents the following characters with reagents.

1. Caustic potass precipitates a white sesquioxide, but only if the solution is tolerably concentrated. The first portions of the test have no effect. The precipitate is redissolved by an excess of potass.

2. Nitric acid throws down a white precipitate, and takes it up again when added in excess.

3. The Infusion of Galls causes a dirty, yellowish-white precipitate; but it will not act on a solution which contains much less than two grains per ounce.

4. The best liquid reagent is Hydrosulphuric acid. In a solution containing only an eighth part of a grain per ounce, it strikes an orange-red colour, which, when the excess of gas is expelled by heat, becomes an orange-red precipitate; and if the proportion of salt is greater, the precipitate is thrown down at once.—The colour of the precipitate is so peculiar as to distinguish it from every other sulphuret; but if any doubt regarding its nature should occur, it may be known by collecting it, dissolving it with the aid of gentle heat in hydrochloric acid, and adding water to the solution; which will then yield a white precipitate, the sesquioxide of antimony in union with a little chlorine.

5. When the solution is put into Marsh’s apparatus for detecting arsenic [p. [211]], the flame yields a dark brownish-black, obscurely shining crust on a surface of porcelain held across it, and a white crystalline powder if the porcelain be held just above the flame. The dark crust is antimony, the white one its oxide. The former has only a distant resemblance to the brilliant stain of arsenic, notwithstanding all that has been said of their similarity. It is well, however, to use some other test for distinguishing the two metals besides their appearance; and the most convenient is a solution of chloride of lime, which instantly makes an arsenical crust disappear, but does not affect an antimonial one.

Tartar-emetic, like the soluble salts of mercury and copper, is decomposed by various organic principles. All vegetable substances that contain a considerable quantity of tannin have this effect; of which an example has been already mentioned in the action of infusion of galls. Decoctions of cinchona-bark decompose it still more effectually. The animal principles do not act on tartar-emetic, with the exception of milk, which is slightly coagulated by a concentrated solution. Many vegetable and animal substances, though they do not decompose it, alter the operation of the fluid tests. Thus tea, though it does not effect any distinct decomposition of the salt, will prevent the action of gall-infusion; and French wine gives a violet tint to the precipitates with that test and with acids.[^[1130]] Hydrosulphuric acid, however, acts under all circumstances, and always characteristically, whatever the colour of the fluid may be. Dr. Turner found that when transmitted through a diluted solution in tea, porter, broth, and milk, with certain precautions to be mentioned presently, he procured a precipitate which either showed its proper colour at once, or did so at the margin of the filter on which it was collected.[^[1131]]

The circumstances now referred to render it necessary to resort to other means, besides the simple application of liquid reagents, for the purpose of detecting tartar-emetic in complex organic mixtures. This subject has been ably investigated, first by Dr. Turner,[^[1132]] and afterwards by Professor Orfila.[^[1133]] The result of the researches of both seems to me to be that the most convenient method yet proposed is the following.

Process for Tartar-emetic in Organic Mixtures.—If the subject of analysis be not already liquid enough, add distilled water. Then acidulate with a little hydrochloric and tartaric acids; the former of which throws down some animal principles, while the latter dissolves readily all precipitates formed with tartar-emetic by reagents or organic principles except the sulphuret. Filter the product.

1. Subject a small portion of the liquid to a stream of hydrosulphuric acid gas, and if it be perceptibly coloured orange-red, treat the whole liquid in the same way; boil to expel the excess of gas, collect the precipitate, dry it, and reduce it by hydrogen gas in the following manner. Put the sulphuret in a little horizontal tube, transmit hydrogen through the tube by means of the apparatus represented in Figure 9, and when all the air of the apparatus is expelled, apply heat to the sulphuret with a spirit-lamp. Hydrosulphuric acid gas is evolved, and metallic antimony is left, if the current of hydrogen be gentle, or it is sublimed if the current be rapid.—When there is much animal or vegetable matter present in the sulphuret, the metal is not always distinctly visible. In that case, dissolve the antimony by the action of nitric acid on the mixed material and broken fragments of the tube, and throw down the orange sulphuret again from the neutralized solution by hydrosulphuric acid.

2. If hydrosulphuric acid do not distinctly affect the liquid, or if no precipitate be separated after boiling, or so small a quantity as cannot well be collected,—evaporate the liquid to dryness, char it by means of nitric acid and chlorate of potash, as directed for copper (p. [357]), boil the carbonaceous mass for half an hour in a mixture of eight parts of hydrochloric acid and one of nitric acid, and introduce the filtered solution into the modification of Marsh’s apparatus for detecting arsenic described in page [204], but without the tube e h. Kindle the gas at e, and try whether a black, dull stain, not removable by solution of chloride of lime, be produced on a surface of porcelain held across the flame. If no stain be produced, there was no antimony in the liquid under examination. If the porcelain be stained, apply the heat of a spirit-lamp flame to the tube d e. Antimony will be deposited within the tube where the heat is applied. In order to ascertain its nature, break the tube, heat the portion containing the crust with nitro-hydrochloric acid, evaporate to dryness, dissolve the residue in hydrochloric acid, decompose a part of this solution with water, and subject the rest to a stream of hydrosulphuric acid gas, which will produce the usual orange sulphuret of antimony.

3. If antimony be not indicated in either of these ways in the fluid part of the subject of analysis, the solid portion may next be subjected to the second process; but success will very seldom attend the search when the previous steps have failed.

The first branch of this process,—a slight modification of Dr. Turner’s,—is a very delicate and satisfactory method of detecting antimony in organic mixtures. Some practice is required to transmit the hydrogen gas with the proper rapidity. The gas ought to be allowed to pass for some time before the spirit-lamp flame is applied, otherwise the oxygen remaining in the apparatus may cause an explosion, or will oxidate the metallic antimony, formed by the reduction of the sulphuret. As soon as the reduction of the sulphuret begins, the tube is blackened on account of the action of the sulphuretted-hydrogen on the lead contained in the glass. This obscures the operations within the tube; but on subsequently breaking it, a metallic button or a sublimate will be easily seen. When the sulphuret is considerable in quantity and the gaseous current slow, the metal remains where the sulphuret was; but if the mass of sulphuret is small and the current rapid, then the metal is sublimed and condensed in minute scaly brilliant crystals.

The second branch of the process is a modification of the method lately employed by Professor Orfila for detecting antimony in the textures and secretions of animals poisoned with tartar-emetic. It is probably more delicate than the other, but not more satisfactory.

The method of analysis here recommended, as well as every other yet proposed for organic mixtures, merely detects the presence of antimony. It does not indicate the state in which the metal was combined. It is a process in short for antimony in every state of combination.

It is almost unnecessary to observe that when the contents of the stomach or vomited matters are the subject of analysis, care must be taken to ascertain that tartar-emetic was not administered as a remedy.

Section II.—Of the Action of Tartar-Emetic, and the Symptoms it excites in Man.

There is little peculiarity in what is hitherto known of the symptoms of poisoning with tartar-emetic in man. Cases in which it has been taken to the requisite extent are rarely met with; and it has seldom remained long enough in the stomach to act deleteriously. But its action on animals would appear from the experiments of Magendie to be in some respects peculiar.

He found that dogs, like man, may take a large dose with impunity, for example half an ounce, if they are allowed to vomit; but that if the gullet is tied, from four to eight grains will kill them in a few hours. His subsequent experiments go to prove that death is owing to the poison exciting inflammation in the lungs. When six or eight grains dissolved in water were injected into a vein, the animal was attacked with vomiting and purging, and death ensued commonly within an hour. In the dead body he found not only redness of the whole villous coat of the stomach and intestines, but also that the lungs were of an orange-red or violet colour throughout, destitute of crepitation, gorged with blood, dense like the spleen, and here and there even hepatized. A larger quantity caused death more rapidly without affecting the alimentary canal; a smaller quantity caused intense inflammation there and death in twenty-four hours; but the lungs were always more or less affected.[^[1134]]

It is a fact, too, worthy of notice, that in whatever way this poison enters the body its effects are nearly the same. This is shown not only by the researches of Magendie already mentioned, but likewise by the experiments of Schloepfer, who found that a scruple dissolved in twelve parts of water and injected into the windpipe, caused violent vomiting, difficult breathing, and death in three days; and in the dead body the lungs and stomach were much inflamed, particularly the former.[^[1135]] It farther appears from an experiment related by Dr. Campbell, that, when applied to a wound, it acts with almost equal energy as when injected into a vein. Five grains killed a cat in this way in three hours, causing inflammation of the wound, and vivid redness of the stomach.[^[1136]] He did not find the lungs inflamed.

Magendie infers from his own researches that tartar-emetic occasions death when swallowed, not by inflaming the stomach, but through means of a general inflammatory state of the whole system subsequent to its absorption,—of which disorder the affection of the stomach and intestines and even that of the lungs are merely parts or symptoms. The later experiments of Rayer tend in some measure to confirm these views, by showing that death may occur without inflammation being excited any where. In animals killed in twenty-five minutes by tartar-emetic applied to a wound, he, like Dr. Campbell, could see no trace of inflammation in any organ of the great cavities.[^[1137]]

Orfila has proved by analysis the important fact that tartar-emetic is absorbed in the course of its action, and may be detected in the animal tissues and secretions. He found that, when it is applied to the cellular tissue of small dogs, two grains disappear before death: That antimony may be detected by his process given above throughout the soft textures generally, but especially in the liver and kidneys: but that it is quickly discharged from these quarters through the medium of the urine. Hence in an animal that died in four hours he found it abundantly in the liver and still more in the urine; in one that survived seventeen hours, the liver presented mere traces of the poison, but the urine contained it in abundance; and in one that lived thirty-six hours, there was a large quantity in the urine, but none at all in the liver. He also ascertained that antimony is generally to be found in the urine of persons who are taking tartar-emetic continuously in large doses for pneumonia according to Rasori’s mode of administering it.[^[1138]] These results have been confirmed by the conjoined researches of Panizza and Kramer, who found antimony in the urine and blood of a man during a course of tartar-emetic.[^[1139]] And Flandin and Danger also satisfied themselves that in animals it may be generally detected in the liver.[^[1140]]

Effects on Man.—When tartar-emetic is swallowed by man, it generally causes vomiting very soon and is all discharged; and then no other effect follows. But if it remains long in the stomach before it excites vomiting, or if the dose be large, more permanent symptoms are sometimes induced. The vomiting recurs frequently, and is attended with burning pain in the pit of the stomach, and followed by purging and colic pains. There is sometimes a sense of tightness in the throat, which may be so great as to prevent swallowing. The patient is likewise tormented with violent cramps. Among the cases hitherto recorded no notice is taken of pulmonary symptoms; which might be expected to occur if Magendie’s experiments are free of fallacy.

The late introduction of large doses of tartar-emetic into medical practice having excited some doubt as to its poisonous properties, it becomes a matter of some moment to possess positive facts on the subject. The following cases may therefore be quoted, which will satisfy every one that this substance is sometimes an active irritant.

The first is particularly interesting from its close resemblance to cholera. It occurred in consequence of an apothecary having sold tartar-emetic by mistake for cream of tartar. The quantity taken was about a scruple. A few moments afterwards the patient complained of pain in the stomach, then of a tendency to faint, and at last he was seized with violent bilious vomiting. Soon after that he felt colic pains extending throughout the whole bowels, and accompanied ere long with profuse and unceasing diarrhœa. The pulse at the same time was small and contracted, and his strength failed completely; but the symptom which distressed him most was frequent rending cramp in the legs. He remained in this state for about six hours, and then recovered gradually under the use of cinchona and opium; but for some time afterwards he was liable to weakness of digestion.[^[1141]]

The next case to be mentioned, where the dose was forty grains, proved fatal, although the person vomited soon after taking it. The symptoms illustrate well the compound narcotico-acrid action often observed in animals. The poison was taken voluntarily. Before the person was seen by M. Récamier, who relates the case, he had been nearly two days ill with vomiting, excessive purging, and convulsions. On the third day he had great pain and tension in the region of the stomach, and appeared like a man in a state of intoxication. In the course of the day the whole belly became swelled, and at night delirium supervened. Next day all the symptoms were aggravated; towards evening the delirium became furious; convulsions followed; and he died during the night, not quite five days after taking the poison.[^[1142]]

Severe effects have also been caused by so small a dose as six grains. A woman, who swallowed this quantity, wrapped in paper, was seized in half an hour with violent vomiting, which soon became bloody. In two hours the decoction of cinchona was administered with much relief. But she had severe colic, diarrhœa, pain in the stomach, and some fever; of which symptoms she was not completely cured for five days.[^[1143]] A case has been published, where a dose of only four grains caused pain in the belly, vomiting, and purging, followed by convulsions, failure of the pulse, and loss of speech; and recovery took place very slowly.[^[1144]] Under the head of the treatment another case will be noticed where half a drachm excited severe symptoms, and was probably prevented from proving fatal only by the timely use of antidotes.

While these examples prove that tartar-emetic is occasionally an active irritant in the dose of a scruple or less, it must at the same time be admitted to be uncertain in its action as a poison. This appears from the late employment of it in large doses as a remedy for inflammation of the lungs. The administration of tartar-emetic in large doses was a common enough practice so early as the seventeenth century, and was also occasionally resorted to by physicians between that and the present time. But it is only in late years that, by the recommendations of Professor Rasori of Milan,[^[1145]] and M. Laennec of Paris, it has again become a general method of treatment. According to this method, tartar-emetic is given to the extent of twelve, twenty, or even thirty grains a day in divided doses; and not only without producing any dangerous irritation of the alimentary canal, but even also not unfrequently without any physiological effect whatever. Doubts were at one time entertained of the accuracy of the statements to this effect published by foreign physicians; but these doubts are now dissipated, as the same practice has been tried, with the same results, by many in Britain. Rasori ascribes the power the body possesses of enduring large doses of tartar-emetic without injury, to a peculiar diathesis which accompanies the disease and ceases along with it. And it is said, that the same patients, who, while the disorder continues, may take large doses with impunity, are affected in the usual manner, if the doses are not rapidly lessened after the disease has begun to give way. The testimony of Laennec on the subject is impartial and decisive. He observes he has given as much as two grains and a half every two hours till twenty grains were taken daily, and once gave forty grains in twenty-four hours by mistake; that he never saw any harm result; and that vomiting or diarrhœa was seldom produced, and never after the first day. The power of endurance he found to diminish, but not, as Rasori alleges, to cease altogether, when the fever ceases; for some of his patients took six, twelve, or eighteen grains daily when in full convalescence.[^[1146]] My own observations correspond with Laennec’s, except as to the effects of large doses during convalescence, of which effects I have had no experience. I have seen from six to twenty grains, given daily in several doses of one or two grains, check bad cases of pneumonia and bronchitis, without causing vomiting or diarrhœa after the first day, and also without increasing the perspiration. At the same time I have twice seen the first two or three doses excite so violent a purging and pain in the stomach and whole bowels, that I was deterred from persevering with the remedy. In continued fever too I have repeatedly found that the doses mentioned above did not cause any symptoms of irritation in the stomach or intestines.

The large quantities now mentioned have even been sometimes given in a single dose with nearly the same results. Dr. Christie mentions in his Treatise on Cholera that he sometimes gave a scruple in one dose with the effect of exciting merely some vomiting and several watery stools. But he admits that in one instance symptoms were induced like those of a case of violent cholera.[^[1147]]

The same large doses have been given by some in delirium tremens without any poisonous effect being produced. A correspondent of the Lancet has even mentioned that on one occasion, after gradually increasing the dose, he at last wound up the treatment, successfully as regarded the disease, and without any injury to the patient, by giving four doses of twenty grains each, in the course of twenty minutes.[^[1148]]

These facts are sufficiently perplexing, when viewed along with what were previously quoted in support of the poisonous effects of tartar-emetic. On a full consideration of the whole circumstances, however, I conceive the conclusion which will be drawn is, that this substance is not so active a poison as was till lately supposed;—that in the dose of four, six, or ten grains, it may cause severe symptoms, but is uncertain in its action,—and that although there appears to be some uncertainty in the effects of even much larger doses, such as a scruple, yet in general violent irritation will then be induced, and sometimes death itself.

An instance is related in the Journal Universel of a man who, while in a state of health, swallowed seventeen grains, and then tried to suffocate himself with the fumes of burning charcoal. He recovered, though not without suffering severely from the charcoal fumes; but he could hardly be said to have been affected at all by the tartar-emetic.[^[1149]] Here the inactivity of the poison was probably owing to the narcotic effects of the fumes.

The effects of tartar-emetic on the skin are worthy of notice; but they have not yet been carefully studied. Some facts tend to show that even its constitutional action may be developed through the sound skin. Mr. Sherwen attempted to prove by experiments on himself and two pupils, that five or seven grains in solution will, when rubbed on the palms, produce in a few hours nausea and copious perspiration.[^[1150]] His observations have been confirmed by Mr. Hutchinson.[^[1151]] But Savary, a French physician, on repeating these experiments, could remark nothing more than a faint flat taste and slight salivation;[^[1152]] and Mr. Gaitskell could not remark any constitutional effect at all.[^[1153]] Sometimes it has appeared to cause severe symptoms of irritant poisoning when used in the form of ointment to excite a pustular eruption. An instance of this has been described in a late French Journal.[^[1154]] Nay, in the Medical Repository there is a case, in which the external use of tartar-emetic ointment is supposed to have been the cause of death. The subject was an infant, two years old, who, soon after having the spine rubbed with this ointment, was seized with great sickness and frequent fainting, which in forty-eight hours proved fatal.[^[1155]] Considering the numerous opportunities which medical men have had of witnessing the effects of tartar-emetic applied in the same manner, and that these are solitary cases, doubts may be entertained whether the irritant symptoms in the one case, or the child’s death in the other, were occasioned in the way supposed.

Although the constitutional action of tartar-emetic is not easily developed through the sound skin, its local effects are severe and unequivocal. When applied to the skin it does not corrode, but excites inflammation, on which account it is much used instead of cantharides. It does not blister; but after being a few days applied, it brings out a number of painful pustules; if it be persevered in, the skin ulcerates; and if it be applied to an ulcerated surface it causes profuse suppuration, or sometimes even sloughing.

Tartar-emetic is one of the substances which appear to possess the property of acting on the infant through the medium of its nurse’s milk. I do not know, indeed, what may be the general experience on this point; but a French physician, M. Minaret, has published a clear case of the kind, in the instance of a young woman who was taking tartar-emetic for pleurisy, and whose infant was attacked with a fit of vomiting immediately after every attempt to suck the breast.[^[1156]]

There is some reason to suppose, that the vapours of antimony may prove injurious when inhaled. Four persons, constantly exposed in preparing antimonial compounds to the vapour of antimonious acid and chloride of antimony, were attacked with headache, difficult breathing, stitches in the back and sides, difficult expectoration of viscid mucus, want of sleep and appetite, mucous discharge from the urethra, loss of sexual propensity, atrophy of the testicles, and a pustular eruption on various parts, but especially on the scrotum. They all recovered.[^[1157]]

Section III.—Of the Morbid Appearances produced by Tartar-emetic.

The morbid appearances caused by tartar-emetic have not been often witnessed in man.

In M. Récamier’s case there were some equivocal signs of reaction in the brain. The organs in the chest were healthy. The villous coat of the stomach, except near the gullet, where it was healthy, was everywhere red, thickened, and covered with tough mucus. The whole intestines were completely empty. The duodenum was in the same state as the stomach; but the other intestines were in their natural condition.

M. Jules Cloquet observed in the body of a man who died of apoplexy, and who in the course of five days had taken forty grains of tartar-emetic, without vomiting or purging,—that the villous coat of the stomach had a deep reddish-violet colour, with cherry-red spots interspersed; and that the whole small intestines were of a rose-red tint spotted with cherry-red.[^[1158]]

The only other dissection I have seen noticed is one by Hoffmann. He says that in a woman poisoned by tartar-emetic he found the stomach gangrenous, and the lungs, diaphragm, and spleen as it were in a state of putrefaction.[^[1159]] Little credit can be given to this description.

In animals Schloepfer found the blood always fluid.[^[1160]]

Section IV.—Of the Treatment of Poisoning with Antimony.

The treatment of poisoning with tartar-emetic is simple. If the poison be not already discharged, large draughts of warm water should be given and the throat tickled, to bring on vomiting. At the same time some vegetable decoction should be prepared, which possesses the power of decomposing the poison; and none is better or more likely to be at hand than a decoction of cinchona-bark, particularly yellow-bark. The tincture is also a good form for giving this antidote. The administration of bark has been found useful even after vomiting had continued for some length of time, probably because a part of the poison nevertheless remained undischarged. Before the decoction is ready, it is useful to administer the bark in powder. It is alleged, however, by M. Toulmouche that decoction of cinchona is not nearly so serviceable as infusion of galls, and that powder of galls is better still.[^[1161]] When there is reason to believe that the patient has vomited enough, and that a sufficient quantity of the antidote has been taken, opium is evidently indicated and has been found useful; but venesection may be previously necessary if the signs of inflammation in the stomach are obstinate.

The following case related by M. Serres was probably cured by cinchona. At all events, the effect of the antidote was striking. A man purchased half a drachm in divided doses at different shops, and swallowed the whole in a cup of coffee. Very soon afterwards he was attacked with burning pain in the stomach, convulsive tremors, and impaired sensibility,—afterwards with cold clamminess of the skin, hiccup, and some swelling of the epigastrium, but not with vomiting. Decoction of cinchona was given freely. From the first moment almost of its administration he felt relief, and began to sweat and purge. Next morning, however, he vomited, and for some days there were evident signs of slight inflammation in the stomach; nay, for a month afterwards he had occasional pricking pains in that region; but he eventually recovered.[^[1162]] Another and more pointed case has been related by Dr. Sauveton of Lyons. A lady swallowed by mistake for whey a solution of sixty grains of tartar emetic. In ten minutes she was seen by her physician, and at this time vomiting had not commenced. Tincture of bark was immediately given in large doses. No unpleasant symptom occurred except nausea and slight colic.[^[1163]]

Orfila considers that the diuretic plan of treatment recommended by him for arsenic [p. [288]] is equally applicable in the case of antimony. Having ascertained that a grain and a half of tartar-emetic applied to a wound constantly killed dogs in a period varying from seventeen to thirty-six hours, if no treatment was employed,—he administered to them in this way a dose varying from a grain and a half to three grains, and by then giving diuretics effected a cure in four out of five instances.[^[1164]]

Chloride of Antimony.

The chloride of antimony [sesquichloride, muriate, or butter of antimony] being now put to little use and seldom seen except as an intermediate product obtained in the preparation of other compounds of antimony, it is rarely met with as the cause of poisoning, and therefore scarcely deserves notice here, were it not that its effects differ widely from those of tartar-emetic and other antimonials.

It is easily known by the characters mentioned above. It has not yet been made the subject of investigation by experiments on the lower animals. Mr. Taylor has collected three cases of poisoning with it, which show that it is a powerful corrosive and irritant, and that its effects, as hitherto witnessed, seem to depend entirely on this action. In one instance, that of a boy, twelve years old, who swallowed four or five drachms of the solution by mistake for ginger-beer, the symptoms were vomiting in half an hour, then faintness and extreme feebleness, and next day heat in the mouth and throat, difficulty in swallowing, slight abrasions of the lining membrane of the mouth, and general fever; but he got quite well in eight days. In the case of another boy, ten years old, who got about the same quantity by mistake for antimonial wine, there was an immediate sense of choking and inability to speak, then vomiting and pain in the throat, next a general state of collapse, with dilated pupils and a tendency to stupor, and on the subsequent day bright scarlet patches on the throat, with difficulty of swallowing. This patient also recovered completely in a few days. The third was the case of a surgeon who took intentionally between two and three fluid ounces, and was found in an hour by his medical attendant in a state of great prostration, and affected with severe efforts to vomit, violent griping, and urgent tenesmus. Reaction soon ensued, the pain abated, and the pulse rose to 120; a strong tendency to doze succeeded; and in ten hours and a half he expired. The whole inside of the alimentary canal, from the mouth to the jejunum, was black as if charred; the mucous membrane seemed to have been removed along the whole of this extent of the canal; and the submucous and peritoneal coats were so soft as to be easily torn with the finger.[^[1165]]

CHAPTER XVII.
OF POISONING WITH TIN, SILVER, GOLD, BISMUTH, CHROME, ZINC, AND IRON.

Several other metallic compounds produce effects analogous to those of the preparations of arsenic, copper, mercury, and antimony. But they may be passed over shortly; because they are little known as poisons, and it is therefore only necessary that their leading properties be mentioned. They are the compounds of tin, silver, gold, bismuth, chrome, zinc, and iron.

Of Poisoning with Tin.

The chlorides of tin are used in the arts of colour-making and dyeing, and the oxide of tin forms part of the putty-powder used for staining glass and polishing silver plate.

There are two chlorides, the protochloride and bichloride. They both form acicular crystals, which are very soluble. It is needless to notice their tests or chemical history; but in order that the following account of their effects on man and animals may be understood, it is necessary to mention, that they are decomposed by almost all vegetable infusions and animal fluids.

Orfila found, that a solution of six grains of the protochloride injected into the jugular vein of a dog killed it in one minute,—that two grains caused death by tetanus in fifteen minutes,—and that so small a quantity as half a grain caused death in twelve hours, the only symptoms being somnolency and catalepsy or fixedness of position.

To these dreadful effects when introduced into the blood, its effects when swallowed are not nearly proportionate. From eighteen to forty-four grains killed dogs in one, two, or three days, efforts to vomit and great depression being the only symptoms; and after death the stomach was found excessively inflamed, and sometimes ulcerated. Its effects when applied externally are still less violent. Two drachms applied to a wound merely caused violent inflammation and sloughing of the part, and death in twelve days, without any internal symptom during life or appearance after death.[^[1166]]

These phenomena, considered along with the violent symptoms excited when the poison is injected into the veins, show that, when swallowed or applied outwardly, it acts only as a local irritant.

Tin is absorbed in the course of its action, and may be detected in the liver, spleen, and urine, by boiling them in water acidulated with hydrochloric acid, evaporating the decoction to dryness, charring the residue by means of nitric acid as directed for copper, treating the carbonaceous mass with a mixture of twenty parts of hydrochloric acid and one of nitric acid, evaporating the solution to dryness so as to expel any excess of acid, dissolving what is left in hydrochloric acid diluted with twice its volume of water, and then transmitting hydrosulphuric acid gas. If the precipitated sulphuret of tin has not a fine yellow colour, it must be heated with a little strong nitric acid; after which, if the residuum be again dissolved in diluted hydrochloric acid, a characteristic yellow bisulphuret will be thrown down by hydrosulphuric acid gas. This process may be applied to all organic mixtures containing tin.[^[1167]]

The oxide of tin, according to Schubarth, is quite inactive; for he gave an entire drachm to a dog without being able to observe any effect from it whatever.[^[1168]] This is what would be expected from its extreme insolubility. Yet Orfila has stated in the early editions of his Toxicology, and repeats in that of 1843, but without noticing the contradictory observations of Schubarth, that one or two drachms of the oxide occasion in dogs all the phenomena of irritant poisoning, and prove invariably fatal.[^[1169]]

The metal has been proved by Bayen and Charlard to be inactive.[^[1170]] It has been given expressly to dogs without any effect being observed; and it is given in large doses to man for worms, without detriment. No importance therefore can be attached to some alleged cases of poisoning with this metal.[^[1171]]

Cases of poisoning with the preparations of tin are rare. Orfila briefly notices a set of cases which occurred to M. Guersent. Several persons in a family took the protochloride, in consequence of the cook having mistaken a packet of it for salt and dressed their dinner with it. They had all colic, some of them diarrhœa; none vomited; and all recovered in a few days.[^[1172]] A case is related in the Medical Times of death apparently caused by so small a quantity as half a tea-spoonful of a solution of protochloride. The effects were vomiting, acute pain in the stomach, anxiety, restlessness, thirst, and a frequent, hard, small pulse. These symptoms increased next day; and on the third day death took place, preceded by delirium.[^[1173]] As this was a case of suicide, it is probable that some other poison, or a larger dose of the chloride of tin was taken.

Little need be said of the morbid appearances. Besides the signs of violent irritation caused by the poisons of tin in common with other irritants, Orfila always found in dogs a peculiar tanned appearance of the villous coat of the stomach. In the case from the Medical Times the gullet was red, the stomach inflamed externally, and internally thickened, vascular, and pulpy.

Of Poisoning with Silver.

Of the preparations of silver, the only one which requires notice is the nitrate or lunar caustic.

It exists in two forms,—crystallized in broad, transparent, colourless tables,—and fused into cylindrical, crystalline, grayish pencils. Both forms are essentially the same in chemical nature.—The most convenient tests are, 1, Hydrochloric acid, or any hydrochlorate, which even in a state of extreme dilution causes with it a dense white precipitate, passing, under exposure to light, into dark brown; and 2, Ammonia, followed by the solution of oxide of arsenic; if the nitrate of silver is not too much diluted it gives a dark brown precipitate with ammonia, soluble, however, in an excess of that alkali; and when the solution has thus been restored, arsenic throws down a lively yellow precipitate, passing rapidly to brown, if left exposed to the light.

Most organic substances, but in particular all animal fluids, with the exception of gelatin, decompose nitrate of silver.

It appears from the experiments of Orfila, that, like the chlorides of tin, the nitrate of silver is a deadly poison when introduced into the veins; but that, by reason of its facility of decomposition, it cannot enter the blood through ordinary channels in a quantity sufficient to develope any remote action. When two grains in solution were injected into the jugular vein of a dog it died in six minutes, difficult respiration being the chief symptom; the third part of a grain caused death in four hours and a half, violent tetanus having preceded death; and in both animals the blood in the heart was found very black and the lungs gorged, or vivid red. According to Mr. Blake, the salts of silver when directly introduced into the blood, do not act on the heart, but operate by causing obstruction of the capillary system. If they are injected into the aorta, the systemic capillaries are obstructed, the nervous system is consequently oppressed, respiration is arrested through the medium of this nervous oppression, and death takes place by asphyxia, the heart continuing to beat vigorously. If again they are injected into a great vein, immediate obstruction of the pulmonary capillaries takes place, so that the blood ceases to be transmitted to the left side of the heart.[^[1174]]

To the violent action exerted by nitrate of silver when directly admitted into the blood, its effects through the medium of the stomach bear no proportion or resemblance. Thus, when twelve grains of the salt were introduced into the stomach in the solid state, its effects were so slight as not to be distinguishable from those of the ligature on the gullet practised to prevent its discharge by vomiting. When introduced in a state of solution, however, and in a larger dose, in the dose of 36 grains, for example, it is more energetic. Death ensued in thirty-six hours, but without any particular symptoms; and in the dead body the villous coat of the stomach was found generally softened, and corroded near the pylorus by little grayish eschars like those formed by this poison on the skin.[^[1175]]

Hence it appears that nitrate of silver does not act remotely, but simply as a local irritant and corrosive. The corrosion it produces is incompatible with its absorption in large quantity. This inference is confirmed by the experiments of Schloepfer, on its effects when introduced into the trachea. He found that it caused inflammation of the windpipe, and pneumonia passing on to hepatization of the lungs, but no symptom referrible to a remote action.[^[1176]] Its pure corrosive properties have long pointed it out to the surgeon as the most convenient of all escharotics.

Nitrate of silver is absorbed, however, in the course of its action. It would seem to be absorbed when it is taken medicinally in frequent small doses. It is not easy to account otherwise for the singular blueness of the skin, sometimes observed after the protracted use of lunar caustic as a remedy for epilepsy and other diseases.[^[1177]] The effects of the poison on the constitution in such cases are not very well known. It appears, however, that considerable doses may be taken for a great length of time without injury, and that the first and only unpleasant effects produced by its too free administration are such as indicate simply an injury of the stomach. The only exception to this general statement I have met with is a case by Wedemeyer, where, after the remedy had been taken for six months on account of epilepsy, that disease disappeared, and dropsy, with diseased liver at the same time commenced, and soon proved fatal. It is probable, however, that the nitrate of silver had no share in the ultimate event. In this instance the whole internal organs were more or less blue; and metallic silver, it is said, was found in the pancreas, and in the choroid plexus of the brain.[^[1178]] Silver has been found in the urine of persons who were taking it medicinally. A young man who had used the nitrate for some time observed that his urine became muddy soon after being passed, and that the sediment became black if exposed to the light; and when the sediment was digested in ammonia, chloride of silver was detached by neutralizing the ammoniacal liquor.[^[1179]]

But it also appears that some nitrate of silver is absorbed when it is given in a single large dose. For in animals poisoned with it Orfila found that silver may be detected in the liver and spleen by charring these organs with nitric acid as in the instance of poisoning with copper, and then treating the residue with boiling diluted nitric acid, and adding hydrochloric acid to the solution. He also found silver in the urine by charring the extract with heat, acting on the charcoal with ammonia, and saturating the filtered ammoniacal solution,—chloride of silver being then detached.[^[1180]] These results have been confirmed by the experiments of Drs. Panizza and Kramer of Milan,[^[1181]] who found silver in the blood after the administration both of the nitrate and chloride.

Boerhaave has noticed a case of poisoning with this substance, but in very brief terms. He says it caused gangrene. Schloepfer in his thesis notices a case by Dr. Albers of Bremen in which croup was brought on by a bit of lunar caustic dropping into the windpipe. M. Poumarede has related an instance of poisoning with an ounce of nitrate of silver in solution. A few hours afterwards the individual was found insensible, with the eyes turned up, the pupils dilated, the jaws locked, and the arms and face agitated with convulsions. A solution of common salt was immediately given as an antidote. In two hours there was some return of consciousness, and abatement of the convulsions, but still complete insensibility of the limbs, with redness of the features, and pain in the stomach. In eleven hours he could articulate. For thirty-six hours he continued subject to fits of protracted coma; but he eventually recovered. Sixteen hours after taking the poison he vomited a large quantity of chloride of silver.[^[1182]]

The treatment of poisoning with the nitrate of silver is obvious. The muriate of soda by decomposing it will act as an antidote; and any signs of irritation left will be subdued by opium.

Of Poisoning with Gold.

Gold in various states of combination was at one time much used in medicine, and an attempt has been lately made to revive its employment.

Its poisonous properties are powerful, and closely allied to those of the chlorides of tin and nitrate of silver. In the state of chloride it occasions death in three or four minutes when injected into the veins, even in very minute doses; and the lungs are found after death so turgid as to sink in water. But if swallowed, corrosion takes place; the salt is so rapidly decomposed, that none is taken up by the absorbents; and death ensues simply from the local injury.[^[1183]] It has been of late used in medicine in France as an antisyphilitic; but even doses so small as a tenth of a grain have been known to produce an unpleasant degree of irritation in the stomach.[^[1184]]

In the state of fulminating gold, this metal has given rise to alarming poisoning in former times, when it was used medicinally. Plenck in his Toxicologia says it excites griping, diarrhœa, vomiting, convulsions, fainting, salivation; and sometimes has proved fatal.[^[1185]] Hoffmann likewise repeatedly saw it prove fatal, and the most remarkable symptoms were vomiting, great anxiety and fainting. In one of his cases the dose was only six grains.[^[1186]] These compounds are now so little met with that they need not be noticed in greater detail.

Of Poisoning with Bismuth.

Bismuth, in its saline combinations, is also an active poison. One of its compounds, the trisnitrate, white bismuth, or magistery of bismuth, is a good deal used in medicine and the arts; and pearl white, one of the paints used in the cosmetic art, is the tartrate of this metal.

The former substance is an active poison. It is got by dissolving bismuth in nitric acid, and pouring hot water over the crystals; a supernitrate being left in solution, and the trisnitrate thrown down in the form of a white powder.

Orfila found that the soluble part of fifteen grains of the nitrate, when injected into the jugular vein of a dog, caused immediate giddiness and staggering, and death in eight minutes. He also remarked that forty grains mixed with water and introduced into the stomach, caused all the customary signs of irritation, and death in twenty-four hours; and that a great part of the villous coat of the stomach was reduced to a pulpy mass, and likewise exhibited several ulcers.[^[1187]]

Similar effects were produced by the trisnitrate; but a larger dose was required. Two drachms and a half killed a dog in twenty-four hours; and redness and eroded spots were found in the stomach.

In some more recent researches Orfila found that the poison is absorbed, and may be detected, like other metallic poisons, in the liver, spleen, and urine. The process for this purpose, applicable also to all organic mixtures, consists in boiling the solids in water acidulated with a twentieth of nitric acid, evaporating the solution to dryness, charring the residue with nitric acid, as directed for copper, boiling the charcoal in diluted nitric acid, and thus obtaining an acid solution of nitrate of bismuth, which may be known by the effects of water and of hydrosulphuric acid.[^[1188]]

Orfila remarks, that Camerarius of Tübingen once detected the adulteration of wine with the oxide of bismuth, and that the bakers in some parts of England used to render their bread white and heavy by mixing the trisnitrate with flour; but he has not stated his authority for this accusation. It may be discovered in any such mixture by calcining the suspected substance in a crucible, and then separating the metallic bismuth by means of nitric acid. But the adulteration of bread with bismuth is very questionable, as there are many cheaper methods for effecting the purpose, without adding any thing positively deleterious.

The following is the only case with which I am acquainted of poisoning with the preparations of bismuth in the human subject. A man subject to water-brash took two drachms of the trisnitrate with a little cream of tartar by mistake for a mixture of chalk and magnesia. He was immediately attacked with burning in the throat, brown vomiting, watery purging, cramps, and coldness of the limbs, and intermitting pulse, and then with inflammation of the throat, difficult swallowing, dryness of the membrane of the nose, and a constant nauseous metallic taste. On the third day he had hiccup, laborious breathing, and swelling of the hands and face; and suppression of urine was then discovered to have existed from the first. On the fourth day swelling and tension of the belly were added to the pre-existing symptoms, on the fifth day salivation, on the sixth delirium, on the seventh, swelling of the tongue and enormous enlargement of the belly; and on the ninth he expired. The urine continued suppressed till the eighth day.—On inspection of the body it was found that from the back of the mouth to the rectum there were but few points of the alimentary canal free of disease. The tonsils, uvula, pharynx, and epiglottis, were gangrenous, the larynx spotted black, the gullet livid, the stomach very red, with numerous purple pimples, the whole intestinal canal red, and here and there gangrenous, especially at the rectum. The inner surface of the heart was bright red. The kidneys and brain were healthy.[^[1189]]

Of Poisoning with Chrome.

The next metal whose properties deserve notice is chrome. As it is now extensively used in the art of dyeing it is necessary to mention its effects, more especially as they are singular. They have been ascertained experimentally with great care by Professor Gmelin of Tübingen. He found that in the dose of a grain the chromate of potass had no effect when injected into the jugular vein of a dog,—that four grains produced constant vomiting, and death in six days without any other striking symptom,—and that ten grains caused instant death by paralysing the heart. Its effects, when introduced under the skin, are still more remarkable. It seems to cause general inflammation of the lining membrane of the air-passages. When a drachm was thrust in the state of powder under the skin of the neck of a dog, the first symptoms were weariness and a disinclination to eat. But on the second day the animal vomited, and a purulent matter was discharged from the eyes. On the third day it became palsied in the hind legs; on the fourth it could not breathe or swallow but with great difficulty; and on the sixth it died. The wound was not much inflamed; but the larynx, bronchi, and minute ramifications of the air tubes contained fragments of fibrinous effusion, the nostrils were full of similar matter, and the conjunctiva of the eyes was covered with mucus. In another dog, an eruption appeared on the back, and the hair fell off.[^[1190]]

The effects of the salts of chrome on man have not been well ascertained, but seem to be peculiar. Dr. Schindler of Greifenberg relates the following case of fatal poisoning with bichromate of potash. A colourman having swallowed a solution of it, vomiting was brought on by warm water, soap and oil, and kept up until the discharges ceased to be yellow. The man got apparently well and passed a quiet night; but next morning he felt excessively weary, had stitches in his back and kidneys, passed no urine, and was affected with purging. A restless night followed. On the subsequent morning, he lay motionless and like one fatigued to the extremest degree; in which state he died, fifty-four hours after swallowing the poison. The stomach was healthy, the intestines reddish, the kidneys gorged with blood and marbled internally with dark-red patches, and the bladder empty.[^[1191]]—Mr. Wilson of Leeds has described the case of an elderly man who took the poison in the evening, and was found dead about twelve hours afterwards, without any sign of vomiting, purging, or convulsions; and no morbid appearance was found but redness of the villous coat of the stomach, and an inky-like fluid in it, containing a large quantity of bichromate of potash.[^[1192]]

To these facts may be added another not less singular, which my late colleague Dr. Duncan informed me has been observed by the workmen in Glasgow, who use the bichromate of potass in dyeing. When this salt was first introduced into the art of dyeing, the workmen who had their hands often immersed in its solution were attacked with troublesome sores on the parts touched by it; and the sores gradually extended deeper and deeper, without spreading, till they sometimes actually made their way through the arm or hand altogether.[^[1193]]

Of Poisoning with Zinc.

The compounds of zinc, which have been long used in considerable doses in medicine, have sometimes occasioned serious and even fatal effects. Partly on this account, and partly because one of them, the sulphate of zinc, being the emetic most commonly used in the treatment of poisoning, is apt to complicate various medico-legal analyses, it will be proper to notice both its physiological properties and the mode of detecting it by chemical means.

The only important compound of this metal is the sulphate or white vitriol. As usually sold in the shops, it forms small, prismatic crystals, transparent, colourless, of a very styptic metallic taste, and exceedingly soluble in water. That which is kept by the apothecary is tolerably pure; but there is a salt sometimes met with in commerce which contains an admixture of sulphate of iron, and with which the natural action of the tests for zinc is materially modified.

The solution of the pure salt is precipitated white by the caustic alkalis, an oxide being thrown down, which is soluble in an excess of ammonia. The alkaline carbonates also precipitate it white, the carbonate of ammonia being the most delicate of these reagents. The precipitate is soluble in an excess of carbonate of ammonia, and is not thrown down again by boiling. The precipitate produced both by the alkalis and by their carbonates becomes yellow, when heated nearly to redness; and on cooling it becomes again white. This is a characteristic property, by which the oxide of zinc may be known from most white powders. But oxide of antimony is similarly affected. The ferro-cyanate of potass also causes a white precipitate. A stream of sulphuretted-hydrogen likewise causes a white precipitate, the sulphuret of zinc, the colour of which distinguishes the present genus of poisons from all those previously mentioned, as well as from the poisons of lead. The precipitate is apt to be suspended till the excess of gas is expelled by ebullition. The action of this test will not distinguish sulphate of zinc from the salts of peroxide of iron, by which white sulphur is disengaged from the gas in consequence of the peroxide of iron being reduced to the state of protoxide. The same decomposition takes place wherever there is free chlorine, as in impure samples of muriatic or nitric acid.

When the sulphate of zinc contains iron, the alkalis throw down a greenish-white precipitate, the alkaline carbonates a grayish or reddish-white, the ferro-cyanate of potass a light-blue, but sulphuretted-hydrogen the usual white precipitate. Tincture of galls, which merely renders the pure salt hazy, causes a deep violet coagulum if there is any ferruginous impurity.

The sulphate of zinc is acted on by albumen and milk precisely in the same manner as the sulphate of copper. The salt is decomposed, and the metallic oxide forms an insoluble compound with the animal matter.

When the sulphate of zinc has been mixed with vegetable and animal substances, the action of the tests mentioned above is modified. In such circumstances I have found the following process convenient.

The mixture being strained through gauze, it is to be acidulated with acetic acid, and filtered through paper. The acetic acid dissolves any oxide of zinc that may have been thrown down in union with animal matter. The filtered fluid is then to be evaporated to a convenient extent, and treated when cool with sulphuretted-hydrogen gas,—upon which a grayish or white milkiness or precipitate will be formed. The excess of gas must now be expelled by boiling, and the precipitate washed by the process of subsidence and affusion, and collected on a filter. It is then to be dried and heated to redness in a tube. When it has cooled, it is to be acted on by strong nitric acid, which dissolves the zinc and leaves the sulphur. The nitrous solution should next be diluted, and neutralized with carbonate of ammonia; after which the liquid tests formerly mentioned will act characteristically. The effect of carbonate of ammonia, and that of heat on the carbonate of zinc which is thrown down, ought to be particularly relied on.

I have tried this process with the matter vomited after the administration of sulphate of zinc, in a case of pretended poisoning, and found it to answer exceedingly well.

Orfila has lately suggested the following method. Boil the suspected substance in water, evaporate the filtered decoction to dryness, char the residuum with nitric acid as directed for copper in similar circumstances, digest the charcoal in diluted muriatic acid, and subject the filtered solution to hydrosulphuric acid. If the sulphuret be not white, but yellowish from iron, heat it with strong nitric acid, dry the product, and heat it to redness; dissolve it in weak nitric acid; throw down the oxide of iron by an excess of ammonia, which retains the oxide of zinc; and then having filtered the fluid, separate the oxide of zinc by neutralizing the ammonia.[^[1194]]

Orfila has furnished the only accurate information hitherto possessed regarding the effects of sulphate of zinc on the animal system.[^[1195]] He found that dogs might be made to swallow 7½ drachms without any permanent harm being sustained, provided they were allowed to vomit; for in a few seconds the whole poison was invariably discharged, and the animals, after appearing to suffer for four or five hours, gradually recovered their usual liveliness. But the result is different if the gullet be tied: violent efforts to vomit ensue, and death follows in three days, the intermediate phenomena being those of local irritation chiefly, and the appearances in the dead body those of incipient inflammation of the stomach, without corrosion.—When injected into the veins, the effect of sulphate of zinc is much more violent, in an inferior dose. Forty-eight grains occasioned almost instant death; and half the quantity proved fatal in three minutes. Orfila does not appear to have ascertained the cause of death in the last two experiments. But Mr. Blake found that when this salt is injected into the veins in the dose of three grains, it causes some depression of the heart; that thirty grains arrest the action of the heart in eight seconds, leaving that organ exhausted of irritability and full of florid blood in its left cavities; and that when injected into the arterial system in the dose of sixteen grains, it seemed not to cause any obstruction of the capillaries, but to act on the nervous system, producing extreme prostration, without insensibility or convulsions.[^[1196]] These experiments, when taken together, show that sulphate of zinc, though a moderately active irritant, is more indebted for its activity to a remote operation on some vital organ.

Sulphate of zinc is absorbed in the course of its action; for Orfila has lately found it by his process for complex mixtures in the spleen, liver, and urine of animals.[^[1197]]

The effects of the preparations of zinc on man in large doses have not been particularly studied. In the dose of a scruple or a drachm, the sulphate is the most immediate emetic known; and it is to be inferred, that if larger doses are rejected, as is the fact, with equal rapidity, they will in general cause no more harm than the medicinal dose.

Nevertheless, some people have suffered severely from over-doses of sulphate of zinc, and a few have even perished. Instead of presenting here a general view of the symptoms, it will be preferable to relate the heads of such cases as have been published.

The first to be mentioned is related by Foderé, who, in consequence of the violent symptoms produced, assigns to the present poison very active properties. “A patient of mine,” says he, “a custom-house officer, having got from a druggist six grains of sulphate of zinc to cure a gonorrhœa, was attacked with inflammation in the lower belly, attended by retraction of the navel and severe colic, which yielded only to repeated blood-letting, general as well as local, oleaginous emollients, opiates, and the warm bath.”[^[1198]] This case is noticed here chiefly to prevent any one from being misled by it, as it has been quoted by other medico-legal authors. For assuredly some other cause must have co-operated before such symptoms could arise; since I have in many cases given the same dose thrice daily for several days, without ever observing more than slight sickness; and Dr. Babington once gave thirty-six grains thrice a day for some weeks with as little effect.[^[1199]]

Parmentier, the chemist, met with an instance, in which about two ounces of white vitriol in solution were swallowed by mistake. The countenance became immediately pale, the extremities cold, the eyes dull, and the pulse fluttering. The patient, a young lady, then complained of a burning pain in the stomach, and vomited violently. But potass being now administered in syrup, the pain ceased, the vomiting gradually abated, and the lady soon recovered completely.[^[1200]]

In the Journal de Médecine, another instance is related by M. Schueler, in which a very large dose did not produce material injury. The symptoms were pain in the stomach and bowels, with vomiting and diarrhœa. They were dispelled in a few hours by the administration of cream, butter, and chalk.[^[1201]]

The following is a fatal case recorded by Metzger, but it is not a pure example of poisoning with zinc, though accounted such by the relater; for a small quantity of sulphate of copper was mixed with the sulphate of zinc. Three persons in a family took this mixture, which had been given them by a grocer in mistake for pounded sugar. They were all seized with violent vomiting; and a boy twelve years of age died in less than twelve hours.[^[1202]]

Another and an unequivocal case has been lately recorded in Horn’s Archiv from Mertzdorff’s experience. No part of the history of the symptoms is mentioned, except that there had been vomiting. But Mertzdorff has described carefully the morbid appearances, which are interesting; and he detected the poison in the stomach by a satisfactory analysis.[^[1203]]

Two other cases, which are presumed to have arisen from the commercial sulphate of zinc, and which proved fatal, have been recently published by Dr. Sartorius of Aachen; but they do not appear to me to have been satisfactorily traced to this poison, and it is therefore unnecessary to quote them.[^[1204]]

Dr. Werres of Cologne has related the particulars of three cases of poisoning with some preparation of zinc in milk-porridge. One of the persons, a child four years old, was seized with vomiting in three minutes, and, after frequent violent returns of it, died in convulsions within eight hours. The others also suffered severely from vomiting, but recovered.[^[1205]]

It does not appear that workmen who are exposed to the fumes of zinc ever suffer materially. But there is a case in Rust’s Magazin, which shows that these fumes are not quite harmless. An apothecary’s assistant, while preparing philosopher’s wool, incautiously filled the whole laboratory with it. The same day he was seized with tightness in the chest, headache and giddiness; next morning with violent cough, vomiting, and stillness of the limbs; on the third day with a coppery taste in the mouth, some salivation, gripes, and such an increase of giddiness that he could not stand. He was then freely purged, after which a fever set in, ending in perspiration; and he got well in three weeks.[^[1206]]

From these cases, and the experimental researches of Orfila, it is clear that the preparations of zinc, though not very active poisons, are nevertheless far from being innocuous. We are not acquainted with their effects when long and habitually introduced into the body in small quantities. About the time when physicians began to study with care the dangerous consequences of employing lead and copper in the manufacture of culinary vessels, it was conceived by some that zinc might prove a safe substitute. It was farther imagined by some military economists in France, that zinc might be profitably used instead of tinned iron in the manufacture of canteens and other articles of camp equipage, because the worn and damaged vessels would sell as old metal at little short of their original price, while tinned iron as old metal bears no value at all. But from the experiments of Deyeux and Vauquelin it subsequently appeared, that in the course of many culinary operations zinc is more liable to be attacked than either copper or lead;—that water left for some time in zinc vessels oxidates them, and acquires a metallic taste;—that if water acidulated with vinegar or lemon-juice is boiled in zinc, a solution is formed, in which the metal may be detected by its tests;—and that sea-salt, sal-ammoniac, and even butter, have the power of dissolving it also.[^[1207]] Some singular inquiries were afterwards prosecuted by Devaux and Dejaer among the Spanish prisoners at Liége, with the view of proving, that frequent small quantities of zinc dissolved in the manner mentioned, and habitually taken with the food, have no injurious tendency; that even in large doses it can hardly be accounted poisonous, as it merely gives rise to vomiting and slight diarrhœa; and that an adulteration to such an amount would always betray itself by its strong disagreeable taste.[^[1208]] These are certainly valuable facts, though not quite satisfactory. But it is unnecessary to inquire minutely into their validity; for, independently of all other considerations, vessels constructed of zinc are too brittle for domestic purposes. With regard to the effects of frequent small doses of sulphate of zinc, the only positive information I can communicate is, that I have often given medicinally from three to six grains thrice a day for two or three weeks, without observing any particular effect except in some persons sickness when the largest doses were taken; and others have frequently made the same observation.[^[1209]] On the other hand, Dr. Nasse of Berlin says a patient of his, who had taken twenty grains of oxide of zinc daily till 3247 grains were swallowed, was attacked with paleness, emaciation, weakness of intellect, obstinate constipation, coldness and œdema of the limbs, extreme dryness of the skin, and a thready scarcely perceptible pulse. But he quickly recovered under the use of laxatives and tonics.[^[1210]]

Sulphate of zinc is said to have proved fatal when applied externally. In Pyl’s memoirs there is a case of this nature, which was attributed to sulphate of zinc having been used as a lotion for a scabby eruption on the head. The subject was a child, six years old, and otherwise healthy. The wash, which was a vinous solution, had not been long applied before the child complained of acute burning pain of the head, which was followed by vomiting, purging, convulsions, and death in five hours. The cause of these symptoms, though the particulars of the case were ascertained judicially by an able medical jurist, Dr. Opitz of Minden, is nevertheless very doubtful, as daily use is made of the salt for similar purposes without any such effect. Appearances of congestive apoplexy were found within the skull; and the reporter ascribes death to the wash having produced repulsion of the cutaneous disease, and determination of blood to the head.[^[1211]]

The only opportunities which have occurred of observing the morbid appearances after poisoning with sulphate of zinc taken internally, are the cases by Metzger, Mertzdorff, and Werres.

In the first, which was a mixed case, the only appearances of note were slight inflammation in the stomach, and excessive gorging of the lungs with fluid blood; from which Metzger oddly enough concludes that the child was suffocated by the vomiting. In the second case, Mertzdorff found the stomach and intestines, but particularly the latter, contracted,—their outer surface healthy—the inner membrane of the stomach grayish-green, with several spots of effused blood, and greenish, fluid contents,—the inner membrane of the small intestines similarly spotted,—the rest of the body quite natural. It has been already mentioned that Mertzdorff detected the poison in the body. He found it not only in the contents, but likewise in the coats of the stomach and intestines. In the third, Werres found a reddish-brown patch and some vascularity in the stomach.

Of Poisoning with Iron.

In previous editions of this work the preparations of iron were arranged among those substances which are not usually considered poisonous, but which may nevertheless prove injurious when taken in large quantity. But the soluble salts of iron, although not very active, seem sufficiently so to entitle them to a regular place among poisons; and one of them, the sulphate, has actually been used, as will presently appear, for the purpose of committing murder. There are many soluble salts of iron which in all probability may prove hurtful; but the only ones which have been brought under notice in medico-legal researches are the sulphate of the protoxide, and the mixed chlorides.

The sulphate of the protoxide of iron, commonly called green vitriol or copperas, occurs in commerce in crystals or crystalline masses of various shades of bluish-green. It is easily known by its colour and its strong styptic inky taste. When in solution, the iron may be detected by ferro-cyanate of potash, sulphuretted-hydrogen, and tincture of galls. Ferro-cyanate of potash causes a blue precipitate, at first pale, but gradually passing to deep Prussian blue. Sulphuretted-hydrogen has no effect, but if an alkali, such as ammonia, be added to disengage the oxide of iron, a black precipitate of sulphuret of iron is immediately produced. Tincture of galls occasions a deep purplish-black precipitate, the tannate of iron, and it acts with greater delicacy in very diluted solutions, if the oxide of iron be disengaged by carbonate of soda. These tests prove the presence of iron in solution. A white precipitate under the action of nitrate of baryta will indicate that the oxide is dissolved by sulphuric acid.

The most familiar form of chloride of iron is the tincture of the chloride, which sometimes contains only the sesquichloride, sometimes consists of a mixture of this with the protochloride. It is known by the three tests for oxide of iron described above, and by nitrate of silver occasioning a heavy white precipitate, insoluble in nitric acid.

For detecting iron in organic mixtures, where the liquid reagents do not act satisfactorily, the simplest process is to digest the mixture, if there be any solid matter, in water acidulated with acetic acid, to evaporate the filtered liquid to dryness, to incinerate the extract in a porcelain crucible, to act on the product with diluted sulphuric acid, and then to treat the solution with the three liquid reagents.

Professor Gmelin found that sulphate of iron merely caused vomiting in dogs who were made to swallow two drachms of it, that rabbits might take forty grains without any apparent injury, and that twenty grains in a state of solution might even be injected into the veins of a dog without producing any particular symptom.[^[1212]] From these and some other facts of the like kind it was generally held, that sulphate of iron is not a poison. But Smith ascertained that a dose of two drachms will prove fatal to dogs in little more than twenty-tour hours, when it is introduced into the stomach, and in half that time if applied to a wound; and that it occasions some redness of the alimentary mucous membrane, and the effusion of a thick layer of tough mucus. It is remarkable, however, that, like Gmelin, he found no effect to flow from the transfusion of a solution of seven grains into the veins, except transient vomiting and expressions of pain.[^[1213]]

The effects which have been observed in the human subject are conformable with those witnessed in experiments on the lower animals, the symptoms being those of pure irritant poisoning. Few illustrative cases, however, have as yet been made public. In Rust’s Journal there is the case of a girl, who took as an emmenagogue, an ounce of green vitriol dissolved in beer, and suffered in consequence from colic pains, constant vomiting and purging for seven hours, but eventually recovered under the use of mucilaginous and oily drinks.[^[1214]] A fatal case of poisoning with this substance occurs in the Parliamentary Returns of death from poison in England during the years 1837–38 [see p. [90]].—Dr. Combe of Leith has communicated to me an instructive case of fatal poisoning with the tincture of the chloride of iron, which was taken to the extent of an ounce and a half by a gardener accidentally instead of whisky. Violent pain in the throat and stomach, tension and contraction of the epigastrium, and nausea immediately ensued; afterwards coldness of the skin and feebleness of the pulse were remarked; and then vomiting of an inky fluid, with subsequently profuse vomiting of mucus and blood, and also bloody stools under the use of laxatives. He remained for some days in a very precarious state, but then began to rally, and in three weeks resumed his occupation. But in two weeks more Dr. Combe found him emaciated, cadaverous in appearance, and affected with pains in the stomach, costiveness, and thirst; in which state he lingered for five days more, and then died. In the dead body there was found great thickening towards the pylorus, a cicatrized patch there three inches long and two inches broad, and another large patch of inflammatory redness surrounded by a white border. The preparation taken in this instance contained a third of its volume of hydrochloric acid and a tenth of its weight of oxide of iron; and consequently some of the acid was free.

The following remarkable case, in which I was lately consulted on the part of the Crown, will show that sulphate of iron is a more important poison than has been commonly thought. Suspicions having arisen in December, 1840, respecting the death of a child in the county of Fife about four months before, an investigation was made by the law authorities; and the body was disinterred and inspected by Mr. Dewar and Dr. James Dewar of Dunfermline. It was ascertained that the child, a girl four years of age, and previously in good health, was attacked with violent vomiting and purging immediately after breakfasting on porridge, and died in the course of the afternoon of the same day. A boy two years older, having seen a blue solution put into the porridge, and observing that the porridge had a bad taste, took only three spoonfuls of it, but became for a time very sick. The girl, being fed by a woman in the house, was made to take all her share; and in the course of the day the same person was seen by two children of the family to give a blue solution to the sick girl for drink. The woman was proved to have purchased sulphate of copper, and admitted having bought about this time both that salt and sulphate of iron, for the alleged purpose of dyeing some clothes. Poisoning with sulphate of copper was therefore suspected. On examining the body, which had been buried four months, the Messrs. Dewar found the external parts considerably decayed,—the stomach soft, gelatinous, and of a uniform intense black colour through the whole thickness of its parietes,—the gullet and duodenum similarly affected, but not so deeply on their outer surface,—the spleen, kidneys, and lower parts of the liver similarly stained with a black pulp, which could be wiped off,—and the whole alimentary canal lined with a thick layer of jet-black mucus, from the pharynx down to the very anus. Inferring that the cause of this extraordinary blackness was decomposition of sulphate of copper by hydrosulphuric acid gas disengaged during the decay of the body, they proceeded to search for that metal in the form of sulphuret both in the contents and texture of the stomach, but without success: there was not a trace of copper to be found. Being then led from some circumstances in the analysis to suspect that the black matter might be sulphuret of iron, they proceeded to search for that substance, and ascertained that a large quantity existed both in the textures of the stomach and in the black mucus which lined it. They further ascertained that there was no iron in a state capable of being dissolved by water, but that a much larger quantity of sulphuric acid was associated with the black matter than could have proceeded from the sulphates naturally contained in the animal textures or in the mucous secretions. They had also an opportunity of examining several large buff-coloured stains on various articles of dress, worn by the child and by the woman at the time the poisoning was supposed to have happened; and they detected a large quantity of oxide of iron in all of them. The whole case was subsequently submitted to me for my opinion, together with a portion of the stomach, the entire intestines, and several stained articles of dress. The results of the analysis of the tissues of the stomach, the black intestinal mucus, and the stains on the cloth were the same in my hands.—It is not easy to see how any other conclusion could be drawn from the whole circumstances, than that a soluble preparation of iron had been administered a short time before death, and that it had been entirely decomposed and converted into sulphuret of iron by the evolution of hydrosulphate of ammonia during the decay of the body. In consequence of important defects in the evidence criminating a particular individual, and especially because all the essential facts depended on the testimony of children, who, after the lapse of some time, did not adhere to their original statement, it was judged improper to bring this case to a trial.

A few years afterwards another case somewhat similar was submitted by the law authorities to the same gentlemen, to whom I am indebted for the particulars. A woman far advanced in pregnancy, and enjoying excellent health, was suddenly seized about midnight with vomiting and purging, and died in fourteen hours. Various circumstances having raised suspicions as to the cause of death, the body was disinterred a few days after burial, and carefully examined by Mr. Dewar and Dr. Dewar. The organs were in general healthy. There were some dark-red patches on the villous coat of the stomach, and a general blush pervaded the whole alimentary canal, which was empty of every thing but a reddish-brown mucus. The intestines were in several places irregularly contracted and hard. The stomach, small intestines, and rectum contained iron in large quantity, dissolved either by sulphuric or hydrochloric acid. Sulphate of iron was found in the house.—No trial took place in this instance either, because there was a want of evidence to attach guilt to any particular individual, although it was highly improbable that the woman had taken the poison herself.[^[1215]]

A short notice may here be added of the toxicological effects of the rarer metals, which have been examined chiefly by Professor Gmelin of Tübingen.[^[1216]]—Oxide of osmium is nearly as active as arsenic, for a grain and a half will kill a dog in a few hours by the stomach, and in one hour through a vein. Twelve grains of hydrochlorate of platinum will kill a dog within a day through the stomach, with symptoms of pure irritation; and so will half that quantity through a vein.—The hydrochlorates of iridium and rhodium are rather less active.—The hydrochlorate of palladium is equally powerful when introduced into the stomach, and much more so through a vein, for two-thirds of a grain will kill dogs in a minute.

The salts of other metals appear less active.—Molybdenum, in the form of molybdate of ammonia, seems a feeble poison; thirty grains killed a rabbit in two hours, but produced in dogs merely some vomiting and purging; and ten grains injected into the jugular vein did not prove fatal.—Manganese, according to Gmelin, is likewise a feeble poison, but has peculiar effects. A drachm of the sulphate killed a rabbit in an hour. Thirty grains swallowed by a dog had no effect. Two drachms thrust into the cellular tissue had no effect. Twelve grains injected into a vein occasioned death in five days: and in the dead body, the stomach, duodenum, and liver were found much inflamed. Manganesic acid, according to Professor Hünefeld, appears also to act on the liver, but is a feeble poison. A rabbit received two drachms in three days in doses of ten or fifteen grains, without presenting any symptom except increased flow of urine. Being then killed, the liver was found soft, at one part bright red, elsewhere dark-brownish-red, and it yielded manganese by incineration.[^[1217]] Some singular observations have been lately published by Dr. Couper of Glasgow, the purport of which is, that manganese belongs to the class of insidious, cumulative poisons, and that it has the property of slowly bringing on, in those who breathe or handle the oxide, a paraplegic affection which is incurable unless taken under treatment early. Five cases of the kind occurred subsequently to 1828, in the great chemical manufactory of Tennant and Company, among the workmen employed in grinding the black oxide of manganese.[^[1218]] On the other hand, Dr. Thomson of Glasgow has recently stated that an ounce of sulphate of manganese is an effectual and safe laxative.[^[1219]] Uranium is an active poison when injected into a vein, for three grains of the muriate proves fatal instantly; but dogs may swallow fifteen, or from that to sixty grains without any other effect except slight vomiting [Gmelin]. Cobalt is more active. Thirty grains of the oxide occasion death in a few hours through the stomach. Twenty-four grains of the muriate applied to the cellular tissue excite vomiting. Three grains of sulphate injected into a vein prove fatal in four days.—Tungsten, cerium, cadmium, nickel, and titanium can scarcely be considered poisons. Tungstate of ammonia in the dose of a drachm had no effect when swallowed by a dog; forty grains of tungstate of soda, which is more soluble, operated as an emetic; but this dose will prove fatal to rabbits in a few hours. A drachm of the muriate of cerium had little or no effect on a dog, and half that dose had no effect on a rabbit. The oxide of cadmium in the dose of twenty grains, made a dog vomit; and ten grains had no effect at all.[^[1220]] Twenty grains of sulphate of nickel made a dog vomit; forty grains applied to the cellular tissue had no effect at all on the general constitution; but ten grains injected into the jugular vein occasioned immediate death [Gmelin]. A drachm of titanic acid had no effect on a dog.

CHAPTER XVIII.
OF POISONING WITH LEAD.

Poisoning with lead is a subject of great consequence in Medical Police, as well as Medical Jurisprudence. Its preparations have been used for the purpose of intentional poisoning. At the Taunton Assizes in March, 1827, a servant-girl was tried for attempting to administer sugar of lead to her mistress in an arrow-root pudding: and although the charge was not made out, it appeared from the prisoner’s confession that she really had made the attempt. Sugar of lead has also been often taken by accident.

In relation to medical police lead is a subject of great importance. This metal is used in so many forms, and in so many of the arts, and its effects when gradually introduced into the body are so slow and insidious, that instances of its deleterious operation are frequently met with. Such accidents, indeed, are less common now, than they used to be before the late improvements in chemistry. But they are still sufficiently frequent to render it necessary for the toxicologist to investigate the properties of lead attentively.

Section I.—Of the Chemical History and Tests for the Preparations of Lead.

The physical characters of lead in its metallic state are familiar to every one. It is easily known by the dull bluish-gray colour it assumes when exposed some time to the air, by the brilliant bluish-gray colour of a fresh surface, and by the facility with which it may be cut. The compounds which require particular notice are four in number, litharge, red lead, white lead, sugar of lead, and Goulard’s extract. The first three are very much used by house-painters and glaziers, the last two are extensively employed in surgery, and the sugar of lead is also used in many of the arts.

1. Of Litharge and Red Lead.

Litharge is the protoxide of lead in a state of semivitrification. Red lead is a compound of two equivalents of protoxide and one of deutoxide. The former is generally in the form of a grayish-red heavy powder, sometimes partly crystalline; the latter in the form of a bright red powder approaching in colour to vermilion. They may be known by their colour;—by their becoming black when suspended in water and treated with a stream of sulphuretted-hydrogen gas;—and by litharge being entirely, and red lead partly, soluble in nitric acid, and forming a solution which possesses the properties to be mentioned presently for solutions of the acetate. The chemical actions concerned in these changes are obvious, except in the instance of nitric acid on red lead. Here the acid dissolves the protoxide only, and the deutoxide, which seems to act the part of an acid in the pigment, is separated in the form of a brown powder.

2. Of White Lead.

White lead, which is the carbonate of the metal, is in the form of a heavy snow-white powder, or in white chalk-like masses. It consists of variable proportions of the hydrated oxide and neutral carbonate; those specimens are the whitest which contain most carbonate; and the best English white lead I find to contain four equivalents of carbonate and one of hydrated protoxide. The grayer variety, formed by the action of distilled water on metallic lead, consists of only two of the former to one of the latter.[^[1221]] It may be known by its being blackened like the two former compounds by sulphuretted-hydrogen,—by being soluble with effervescence in nitric acid,—and by becoming permanently yellow when heated to redness, in consequence of the expulsion of its carbonic acid, and its conversion into protoxide. These tests, however, apply with exactness only to the pure carbonate, in which state white lead is not often met with in the shops. It is generally adulterated with sulphates, in consequence of which it is only partially acted on by nitric acid, and does not become distinctly yellow under a strong red heat. Dutch white-lead contains no less than between 78·5 and 25 per cent. of impurities insoluble in nitric acid, Venetian white-lead from 11 to 14·5 per cent., Munich white-lead between 1 and 7·5 per cent.[^[1222]] I have met, however, with perfectly pure specimens in the shops of this city.

3. Of Sugar of Lead.

Sugar of lead is the acetate of this metal. It is sold in the form either of a white heavy powder, or of aggregated masses of long four-sided prismatic crystals. It has a sweetish astringent taste, and a slight acetous odour. It is very soluble.

When in the solid state, it may be known by its solubility in water, and by the effects of heat. It first undergoes the aqueous fusion, then abandons a part of its acid empyreumatized, as may be perceived by the smell, next becomes charred, and finally presents globules of lead reduced by the charcoal of the acid. The best way of effecting its reduction on the small scale is to char it, and then direct on the mass the point of a blowpipe-flame: in an instant globules are developed. It is not easily reduced in a tube; at least I have never been able to succeed in that way.

In the fluid state the acetate of lead, as well as all its soluble salts, may be detected by the following system of reagents,—hydrosulphuric acid, bichromate of potass, hydriodate of potass, and metallic zinc,—which are the best of the numerous reagents yet proposed.

1. Hydrosulphuric acid causes a black precipitate, the sulphuret of lead. This is a test of extreme delicacy; and it acts in whatever state of combination the lead exists, whether fluid or solid.

It is preferable to the hydrosulphate of ammonia as a medico-legal test; for, as Fourcroy observed, the hydrosulphate of ammonia acts on many sound wines as if they contained lead,[^[1223]] while hydrosulphuric acid never causes with them a black precipitate, unless they contain either lead or some other metallic impregnation. It must be remembered that many other metallic solutions, such as those of mercury, copper, silver and bismuth, yield a black precipitate with this test.

2. Chromate of potass, both in the state of proto-chromate and bichromate, causes a fine gamboge-yellow precipitate, the chromate of lead. For the characteristic action of this reagent, it is desirable that the suspected liquid be neutral. It forms with solutions of the sulphate of copper a precipitate nearly of the same colour as the chromate of lead.

3. Hydriodate of potass causes also a lively gamboge-yellow precipitate, the iodide of lead. The action of this test is impaired in delicacy by a considerable excess of nitric acid, or acetic acid. These acids cause a yellow coloration with the test, though no lead be present.

4. A rod of zinc held for some time in the solution displaces the lead, taking its place, and throwing down the lead in the form of a crystalline arborescence. This is a very characteristic test; and also one of much delicacy; for I have found a small thread of zinc will very easily detect a twentieth part of a grain of lead dissolved in the form of acetate in 20,000 parts of water. It acts also on the nitrate of lead. Its action is impaired or prevented by an excess of acetic or nitric acid.

These tests are amply sufficient for determining the presence of lead in a solution, provided they act characteristically. Others have been also used, however; and it is therefore right to notice them cursorily.

The alkaline carbonates throw down a white precipitate in a very diluted solution of lead. This test is ineligible, because the alkaline carbonates cause a white precipitate with many other salts. It might be rendered decisive, however, by washing the precipitate thoroughly, suspending it in pure water and transmitting sulphuretted-hydrogen, which blackens it. No other white carbonate is similarly altered except those of bismuth and silver, which are rare.

The soluble sulphates likewise cause with solutions of lead a white precipitate, the sulphate of lead. To this test the same objections apply as to the carbonates of the alkalis.

The ferro-cyanate of potash causes a white precipitate, the ferro-cyanate of lead. This is an objectionable test, as many other substances besides lead are similarly acted on by it.

4. Goulard’s Extract.

Goulard’s extract, the diacetate of lead, is easily distinguished from the acetate or sugar of lead by the effect of a stream of carbonic acid, which throws down a copious precipitate of carbonate of lead. The proper method of analyzing it is to transmit this gas till it ceases to act any longer, and then to subject the precipitate and solution to the tests for carbonate of lead, and acetate of lead. Solutions of the common acetate usually give a scanty white precipitate with carbonic acid, in consequence of containing a faint excess of oxide.

The presence of vegetable or animal matters may either decompose the salts of lead, or materially alter the action of the preceding reagents.

It appears from the experiments of Orfila, that most vegetable infusions possess the power of decomposing them more or less. The acetate furnishes, for example, an abundant precipitate with infusion of galls, or with infusion of tea. Almost all animal fluids, with the exception of gelatin, possess the same property; albumen, milk, bile, beef-tea, all give with it a copious precipitate. In fluids which do not decompose it altogether, the colour of the precipitate formed by the tests is so materially altered, that they cannot be relied on for the detection of lead. The test, however, which undergoes least alteration is hydrosulphuric acid.

Before proceeding to the detection of lead in complex organic mixtures, some remarks will be required on its relations to medical police. Here the various ways in which it is apt to be insidiously introduced into the body, chiefly by the action of chemical agents on metallic lead itself, will come under consideration.

Of the Action of Air and Pure Water on Lead.

When lead is exposed to the air it becomes tarnished. This arises from a thin crust of carbonate of lead being formed; for the crust dissolves with brisk effervescence in acetic acid. The formation of carbonate is accelerated by moisture and probably by the presence of an unusual proportion of carbonic acid in the air.

The action of water on lead, which is of much greater consequence, has been made the subject of observation by the curious for many ages. The Roman architect, Vitruvius, who, it is believed, nourished in the time of Cæsar and Augustus, forbids the use of this metal for conducting water, because cerusse, he says, is formed on it, which is hurtful to the human body.[^[1224]] Galen also condemns the use of lead pipes, because he was aware, that water transmitted through them contracted a muddiness from the lead, and those who drank such water were subject to dysentery.[^[1225]] If we trace the sciences of architecture, chemistry, and medicine downwards from these periods, nothing more will be found than a repetition of the statements of Vitruvius and Galen, with but a few particular facts in support of them, till we arrive at the close of the last and beginning of the present century.

The first person that examined the subject minutely, was Dr. Lambe of Warwick; who inferred from his researches, that most, if not all, spring waters possess the power of corroding and dissolving lead to such an extent as to be rendered unfit for the use of man, and that this solvent power is imparted to them by some of their saline ingredients.[^[1226]] The inquiry was afterwards undertaken more scientifically by Guyton-Morveau; who, in opposition to Dr. Lambe, arrived at the conclusion, that distilled water, the purest of all waters, acts rapidly on lead by converting it into a hydrated oxide, and that some natural waters, which hardly attack lead at all, are prevented doing so by the salts they hold in solution.[^[1227]] A few years later Dr. Thomson of Glasgow also examined the subject, and, assenting to Dr. Lambe’s proposition, that most spring waters attack lead, maintains nevertheless that the lead is only held in suspension, not in solution; and that the quantity suspended in such waters, after they have passed through lead pipes, pumps, and cisterns, is too minute to prove injurious to those who make habitual use of them.[^[1228]] In the first edition of this work an extended account was given of an investigation I made into the whole subject of the action of different waters on lead.[^[1229]] Additional observations were afterwards published on the same point by Captain Yorke,[^[1230]] and by Mr. Taylor.[^[1231]] And I have added some new facts in a late paper.[^[1232]]

The inquiry is of so great practical consequence, that I need not offer any apology for reproducing it here in detail, with such additions as ulterior experience and the researches of others enable me to make. Professor Orfila takes no notice of this important subject, except in a few lines containing several inaccurate statements.[^[1233]]

Distilled water, deprived of its gases by ebullition, and excluded from contact with the air, has no action whatever on lead. If the water contains the customary gases in solution, the surface of the metal, freshly polished, becomes quickly dull and white. But if the surface of the water be not at the same time exposed to the air, the action soon comes to a close.—When the air, on the other hand, is allowed free access to the water, a white powder appears in a few minutes on and around the lead; and this goes on increasing till in the course of a few days there is formed a large quantity of white matter which partly floats in the water or adheres to the lead, but is chiefly deposited on the bottom of the vessel. If this experiment be made with atmospheric air deprived of carbonic acid, the white substance puts on the form of a fine powder, which I find to be a hydrated oxide; for when dried at 180°F. it gives off water on being heated to redness, and dissolves without effervescence in weak nitric acid.—But if the surface of the water be exposed to the open air, the substance formed consists of minute brilliant pearly scales, which with the aid of a powerful microscope are seen to be thin equilateral triangular tables, often grouped into hexaedral tables, or worn at the edges into the form of rosettes. This substance, which has a pale grayish hue when dried, I have ascertained to be a carbonate of lead, consisting of two equivalents of neutral carbonate and one of hydrated protoxide.[^[1234]] The formation of carbonate takes place with considerable rapidity. In twelve ounces of distilled water, contained in a shallow glass basin loosely covered to exclude the dust, twelve brightly polished lead rods weighing 340 grains, will lose two grains and a half in eight days; and the lead will then show evident marks of corrosion. The process of corrosion goes on so long as atmospheric air is allowed to play freely on the surface of the water. In twenty months I have obtained 120 grains from an ounce of lead rods kept in 24 ounces of distilled water.

During these changes, a minute quantity of lead is dissolved. This is best proved by carefully filtering the water, then acidulating with a drop or two of nitric acid, and evaporating to dryness. I have never failed to detect lead in the residue by expelling the excess of nitric acid by heat, dissolving it in distilled water, and applying hydrosulphuric acid, hydriodate of potass, and chromate of potass to the solution. The lead is first dissolved in the form of hydrated oxide. For, if the air admitted to the water be deprived of carbonic acid, a clear liquid is obtained by filtration, and this is turned brown by hydrosulphuric acid. But a great part of the hydrate is speedily separated in the form of carbonate. For the filtered liquid speedily becomes turbid if exposed to the air; and on evaporating it, the residuum dissolves in weak nitric acid with brisk effervescence. Captain Yorke estimates the quantity dissolved when the water is saturated at a 10,000th part.[^[1235]]

By far the greatest part of the lead, however, which disappears, will be found in the white pearly crystals. This crystalline powder is not,—as alleged by Guyton-Morveau, and after him by some systematic writers, a hydrated oxide of lead, but, as stated above, a particular variety of carbonate, containing more hydrated oxide than exists in common white lead. At first I thought it was neutral carbonate. Captain Yorke was led to suppose it hydrated oxide. In 1842 I found that, if it be exposed for some time to the action of aërated water after the lead has been removed, it invariably consists of two equivalents of neutral carbonate and one of hydrated oxide.

It will be inferred from the preceding facts, that distilled water for economical use should never be preserved in leaden vessels or otherwise in contact with lead. Even the distilled water of aromatic plants should not be so preserved, because the essential oil which communicates to them their fragrance does not take away the power which pure distilled water possesses of acting on lead. This fact was first announced in the second edition of the present work. A druggist in Edinburgh requested me to examine a reddish-gray crystalline, pearly sediment formed copiously in a sample of orange-flower water. I found this to be carbonate of lead coloured by the colouring matter of the water, and obviously produced by the action of the water on lead solder used instead of tin solder, and coarsely and liberally applied to the seams of the copper vessel in which the water had been imported from France. The filtered fluid did not contain a particle of lead. The same observation has been since made by a French pharmaceutic chemist, M. Barateau, who seems at a loss, however, to account for the formation of the carbonate of lead.[^[1236]] It appears from an inquiry of MM. Labarraque and Pelletier, conducted at the request of the Prefecture of Paris, that the orange-flower water, which is extensively used there, is often adulterated with lead in solution. They impute this to careless distillation; for then some of the decoction is driven over with the distilled liquid, and consequently produces a fluid which becomes acetous by keeping and dissolves the lead solder of the estagnons or copper vessels. Pure orange-flower water does not acidify by keeping.[^[1237]] M. Chevallier in a more recent investigation arrived at the same results, and found that few specimens of the orange-flower water of Paris were altogether free of lead.[^[1238]] In none of these inquiries have the authors adverted to the action of pure water in forming carbonate of lead.

Of the Action of Solutions of Neutral Salts on Lead.

The property which pure aërated water possesses of corroding lead is variously affected by foreign ingredients which it may hold in solution.

Of these modifying substances none are more remarkable in their action than the neutral salts, which all impair the corrosive power of the water. Important practical consequences flow from that action; for it involves no less than the possibility of employing lead for most of the economical purposes to which the ingenuity of man has applied that useful metal. The first experimentalist who made it an object of attention was Guyton-Morveau; whose experiments are imperfect and in some respects erroneous. Having found that distilled water corrodes lead, he proceeded to inquire why no change of the kind takes place in some natural waters; and being aware that most spring and river waters differ from that which has been distilled, chiefly in containing sulphate of lime and muriate of soda, he tried a solution of each of these salts, and discovered that the addition of a certain quantity of either to distilled water takes away from it the power of attacking lead,—that this preservative power is possessed by so small a proportion as a 500th part of sulphate of lime in the water,—and that the nitrates are also probably endowed with the same singular property.[^[1239]] Here his researches terminated.

Extending Guyton-Morveau’s inquiries to other proportions of the same salts, and likewise to many other neutral salts, I was led to the conclusion, that all of them without exception possess the power of impairing the action of distilled water on lead. At least I found this power to exist in the case of sulphates, muriates, carbonates, hydriodates, phosphates, nitrates, acetates, tartrates, and arseniates.

The degree of this preservative power differs much in different salts. The acetate of soda is but an imperfect preventive when dissolved in the proportion of a hundredth part of the water: white crystals are formed, and the lead loses about a fourth of what is lost in distilled water in the same time. On the contrary, arseniate of soda is a complete preservative when dissolved in the proportion of a 12,000th; and phosphate of soda and hydriodate of potass are almost effectual preservatives in the proportion of a 30,000th part only of the water.[^[1240]] Muriate of soda and sulphate of lime hold a middle place between these extremes, and are both of them much more powerful than Guyton-Morveau imagined: the former preserves in the proportion of a 2000th to the water, the latter in the proportion of nearly a 4000th. Nitrate of potass is little superior to the acetate of soda: in the proportion of a hundredth it prevents the action of the water almost entirely; but if the proportion be diminished to a 160th, the loss sustained by the lead is fully a third of the loss in distilled water.

When lead has been exposed for a few weeks to a solution of a protecting salt and has acquired a thin film over its surface, it not only is not acted on by the solution, but is even also rendered incapable of being acted on by distilled water.

The preservative power depends on the acid, not on the base of the salt. The acetate, muriate, arseniate, and phosphate of soda differ exceedingly in power. On the other hand, the sulphates of soda, magnesia, and lime, as well as the triple sulphate of alumina and potass, preserve as nearly as can be determined in the same proportion.

When we attempt to ascertain the relative preserving power of the neutral salts, it will appear that those whose acid forms with the lead a soluble salt of lead are the least energetic; while those whose acid forms an insoluble salt of lead are most energetic. The protecting powers of acetate of soda, nitrate of potass, muriate of soda, sulphate of lime, arseniate of soda, and phosphate of soda, are inversely as the solubility of the acetate, nitrate, muriate, sulphate, arseniate, and phosphate of lead. The existence of this ratio might naturally lead to the inference that the protecting power depends simply on the salt in solution being decomposed, so that there is formed on the surface of the lead a thin crust consisting of the oxide of the metal in union with the acid of the decomposed salt, and constituting an insoluble film which is impermeable to aërated water: for example, that phosphate of soda acts in the small proportion of a 30,000th part by forming on the surface of the metal an impermeable film of phosphate of lead, which is known to be one of the most insoluble of all the neutral salts. But this is not altogether a correct statement of the fact.

When the protection afforded is complete, as for example by a 27,000th of phosphate of soda, a 12,000th of arseniate of soda, or a 4000th of sulphate of soda, the lead undergoes no change in appearance or in weight for several hours, or even days. At length the surface becomes dull, then white, and gradually a uniform film is formed over it. This film, examined at an early period, is found to consist of carbonate of lead,—being entirely soluble in diluted acetic acid, although the salts in solution is a sulphate or phosphate. But after a few weeks the carbonate is mixed with a salt of lead, containing the acid of a part of the neutral salt dissolved in the water: if, after five or six weeks’ immersion in a preservative solution of phosphate or sulphate of soda, the film on the lead be scraped off and immersed in diluted acetic acid, effervescence and solution take place, but a part of the powder remains undissolved; and if the protecting salt has been the muriate of soda, the whole powder is dissolved, but muriatic acid will be found in solution by its proper test, the nitrate of silver.—In all such protecting solutions the lead gains weight for some weeks; but at length it ceases to undergo farther change, and is not acted on even if removed into distilled water. The crust, when formed thus slowly, adheres with great firmness. The most careful analysis cannot detect any lead, either dissolved in the water, or floating in it, or united with the insoluble matter left on the side of the glass by evaporation. In short, the preservation of the lead from corrosion, and of the water from impregnation with lead, is complete.[^[1241]]

When the protection afforded is not quite complete,—for example in distilled water containing a 4000th of muriate of soda, a 6000th of sulphate of soda, a 15,000th of arseniate of soda, or a 35,000th of phosphate of soda,—besides a powdery crust, small crystals, with several facettes, are sometimes formed on the lead, while, at the same time, a minute white film will very slowly appear on the bottom of the glass, on its side where it is left dry by the evaporation of the water, and likewise on the surface of the water itself. These detached films are composed of carbonate of lead, with a little of the muriate, sulphate, arseniate, or phosphate of lead, according to the nature of the acid in the alkaline salt which is dissolved in the water. In the course of the changes now described, the lead in general no longer gains, but loses weight. The loss, however, is exceedingly small.—No lead can be discovered in solution, if the water before evaporation is carefully filtered.

On progressively trying solutions of weaker and weaker preservative power, it will be remarked, that the quantity of the detached powder, and the proportion of carbonate in it, progressively increase; and likewise, that what is formed on the lead adheres more and more loosely. In distilled water and weak solutions of acetate of soda, or nitrate of potass, the lead never becomes so firmly encrusted, but that gentle agitation of the water will shake off the powder.

It is worthy of notice that, although a small quantity of lead is dissolved by distilled water after it has remained some time in contact with the metal, yet not a trace is found in solution where a protecting salt is present. In solutions even weakly preservative I never could detect any lead dissolved. Thus, in distilled water containing a 4000th of muriate of soda, or a 160th of nitre, the lead lost weight, and loose crystals of carbonate were formed; yet even after thirty days no lead could be found in solution by the process with which I have always detected it in pure distilled water. Free exposure to the air is probably in part the cause of this. For it will be seen afterwards that some natural waters in passing through a long course of lead pipes, within which the action goes on without direct access of the atmosphere, contract an impregnation, which is invisible when the water is newly drawn, but after a few hours’ exposure to the air shows itself in the form of a white film and milkiness.

The general result of these experiments appears to be, that neutral salts in various, and for the most part minute, proportions, retard or prevent the corrosive action of water on lead,—allowing the carbonate to deposit itself slowly, and to adhere with such firmness to the lead as not to be afterwards removable by moderate agitation, adding subsequently to this crust other insoluble salts of lead, the acids of which are derived from the neutral salts in solution,—and thus at length forming a permanent impermeable skreen, through which the action of the water cannot any longer be carried on.

An important subject of inquiry regards the natural causes by which the preservative power of the neutral salts is impaired. This topic I have not hitherto been able to examine with all the care which is desirable.

From the effect of the water of Edinburgh when highly charged with carbonic acid, I was led to infer in former editions of this work that an unusual quantity of carbonic acid is a counteracting agent. For if Edinburgh water charged with it be corked up with some lead rods in a phial half-filled with water, and half with atmospheric air, the lead, which in common Edinburgh water, as will presently be mentioned, hardly loses any of its brilliancy for six or seven days, becomes quite white in twelve or sixteen hours. Subsequent experiments by Captain Yorke seemed to him to render this conclusion doubtful; nor do I attach much consequence to the observation just quoted. On the other hand it is said Professor Daniell has found all waters dissolve lead, if they contain an excess of carbonic acid.[^[1242]] The point would be best settled by the effect of a natural carbonated water passing through a long lead pipe.

On the Action of Natural Waters on Lead.

The preceding observations on the action of water on lead may be resorted to for explaining many interesting facts, and correcting some erroneous statements, which have been published by authors as to the corrosion of lead by natural processes.

Rain and Snow-Water.—It has been stated by Dr. Lambe that rain-water does not corrode lead, that “its effect is so slight as not to be discernible within a moderate compass of time.”[^[1243]] But this observation is far from being correct. Rain or snow-water, collected in the country at a distance from houses, and before it touches the earth, being nearly as pure as distilled water, ought to act with equal rapidity on lead. I have accordingly found by a comparative experiment with that mentioned in p. [401], that in twelve ounces of snow-water, collected ten miles west from Edinburgh, and at some distance from any house, twelve lead rods weighing 340 grains lost two grains in eight days, and the usual crystals began to form in less than an hour. But when collected in a great city, rain or snow-water is much impaired in activity. Thus in an experiment made with eaves’-droppings collected from the roof of my house in Edinburgh, after half an hour of gentle rain from the south-east,—the first rain which had fallen for several weeks,—there was no action at all. Yet even when collected in a great city, and in circumstances which at first sight would appear not very favourable to its action,—for example from eaves’-droppings a few hours after the beginning of a shower,—it retains a little of its corroding property; and when collected in like manner after twelve or twenty-four hours’ rain, it corrodes almost as rapidly as distilled water. Thus with four ounces of eaves’-droppings collected after the shower last alluded to had continued four hours, the crystalline powder began to cover the bottom of the glass in five hours, and in nine days three lead rods weighing fifty-seven grains lost a fifth of a grain. And in another experiment made with eaves’-droppings after a day’s steady rain from the north-east, the powder began to form in half an hour, and the loss sustained by the lead in thirty-three days was a grain and a third, being very nearly what is lost in distilled water during the same time.

We must obviously be prepared to look for an explanation of these differences in the relative purity of the different waters. Accordingly, in the eaves’-droppings at the beginning of the shower the nitrates of baryta and silver caused, the former a distinct, the latter a faint precipitation, which, as oxalate of ammonia had no effect, arose from the presence of alkaline sulphates and muriates: but after a four hours’ shower nitrate of baryta alone acted, and caused merely a faint haze: and after a twenty-four hours’ shower, as well as in snow-water from the country, none of the three tests had any effect whatever.

Hence, perhaps even in a town, but at all events certainly in the country, it would be wrong to use for culinary purposes rain or snow-water which has run from lead roofs or spouts recently erected. When the roof or spout has been exposed for some time to the weather the danger is of course much lessened, if not entirely removed; because exposure to the weather encrusts it with a firmly adhering coat of carbonate, through which, as already observed, even distilled water will not act. But I believe it would be right to condemn the turning even old leaden roofs to the purpose of collecting water for the kitchen. Although the purest rain-water cannot act on them when it is once fairly at repose, we do not know what may be the effect of the impetus of the falling rain on the crust of carbonate; and if the crust should happen to be thus worn considerably, or detached by more obvious accidents, the corrosion would then go on with rapidity as long as the shower lasted. Acid emanations too disengaged in the neighbourhood, and other more obscure causes may enable rain-water actually to dissolve even the crust of carbonate.

These remarks on the effect of rain-water on lead are pointedly illustrated by what Tronchin has recorded of the circumstances connected with the spreading of the lead colic at Amsterdam, about the time he wrote his valuable essay on that disease. Till that period lead colic was seldom met with in the Dutch capital. But soon after the citizens began to substitute lead for tiles on the roofs of their dwelling-houses, the disease broke out with violence and committed great ravages. Tronchin very properly ascribed its increase to lead entering the body insidiously along with the water, which for culinary purposes was chiefly collected from the roofs during rain. He farther attempts to account for the rain-water having acquired the power of corroding the lead, by supposing that it was rendered acid in consequence of the roofs having been covered with decaying leaves from trees which abounded in the city; and without a doubt this explanation accords with the season at which the lead colic was observed to be most frequent,—namely, the autumn. But he does not seem to have been aware that rain-water itself possesses the corroding property, independently of any extrinsic ingredient except the gases it receives in its passage through the atmosphere.[^[1244]]—Mérat has referred to a Dutch author, Wanstroostwyk, for an account of a similar incident which happened at Haarlem.[^[1245]]

The co-operating effect of acid emanations in the atmosphere is well exemplified by an interesting incident which occurred this year in Manchester, as detailed in some documents put into my hands by Dr. Hibbert Ware. A gentleman being seized with symptoms, which in the opinion of his medical adviser were owing to the insidious introduction of lead into the body, it was found by Mr. Davies that the rain-water from a leaden roof, which had been used in the family for nine years, contained a considerable impregnation of lead. At first this excited some surprise, because the roof was an old one. But on farther inquiry it was found, that the rain in descending contracted an impregnation of hydrochloric acid from the vapours which escaped from an adjoining manufactory. A portion of the water which was sent to me contained so much lead dissolved that it became dark-brown on the addition of hydrosulphuric acid, and a considerable black precipitate was slowly deposited.

Spring Water.—Most spring waters, unlike rain or snow-water, have little or no action on lead, because they generally contain a considerable proportion of muriates and sulphates.

As an example of a spring water which does not act on lead at all, the mineral water of Airthrey, near Stirling, may be mentioned. In four ounces of water from the strongest spring at Airthrey, I kept for thirty-five days three bright rods of lead weighing 47·007 grains; and at the end of that period the rods were very nearly as brilliant as when they were first put in, and weighed 47·004 grains. This result is easily explained on considering the nature of the water. It contains no less than a seventy-seventh part of its weight of saline matters, which are chiefly muriates, and partly sulphates.

Another good illustration occurred to me lately, which contrasts well with some instances of an opposite description to be mentioned presently. The house of Phantassie in East-Lothian was supplied with water by a lead pipe from a distance of a mile. About a year afterwards, when I had an opportunity of examining into the circumstances, I found the cistern singularly clean and free of incrustation, and the water quite free of lead. The composition of the water explained these facts. It contains a 4,900th of salts, a large proportion of which consists of carbonates of lime and magnesia.

The water of Edinburgh is another example of spring water nearly destitute of action on lead. But it is not so completely inactive as the water of Airthrey. In four ounces of water three bright rods weighing fifty-seven grains lost in seven days a 250th of a grain, in twenty-one days a 100th, in thirty-five days a 66th, and in sixty-three days a 59th of a grain. In seven days the lead was hardly tarnished at all, and not a speck of powder could be seen in the water, or on the glass. In twenty-one days, but still more in thirty-five or sixty-three days, the lead was uniformly dull; and on the surface of the water, as well as on the bottom of the glass, and on the side where left dry by the evaporation of the water, there were many white, filmy specks, which became black with the hydrosulphate of ammonia. In another experiment 145 grains of lead kept for six months in six ounces of Edinburgh water, which was filled up as it evaporated, lost a fifteenth of a grain; and the white incrustation on the bottom and sides of the glass gave a large proportion of black precipitate when scraped together and treated with hydrosulphate of ammonia. These experiments are of some practical importance. For they show that the impregnation which the water of Edinburgh can receive in a few days from being kept in lead is so small as to be barely perceptible by the nicest analysis; but that the impregnation may be material if the same portion of water is kept in lead for a considerable length of time. Hence the perfect safety of the leaden cisterns and service-pipes used in this city. The same portion of water rarely remains in them above a single day, and therefore cannot become impregnated in a degree that is appreciable by the nicest examination. Dr. Thomson of Glasgow, in an interesting inquiry made in 1815 into the purity of the water which supplies Tunbridge, has stated that, when he lived in Edinburgh some years before, he could always detect a minute trace of lead suspended in the water, which at that time was brought six miles in leaden pipes.[^[1246]] I presume it is owing to the main pipes being now made of iron that this impregnation no longer exists. For I have found that the residue of two gallons of water, very carefully collected by gentle evaporation of successive portions in a small vessel, did not furnish the slightest trace of lead, when strongly heated with black flux and then acted on by nitric acid.[^[1247]] The feeble action of the Edinburgh water on lead arises from the salts it holds in solution. It contains about a 12,000th part of its weight of solid matter, of which about two-thirds are carbonate of lime, and one-third consists of the sulphates and muriates of soda, lime, and magnesia.

Many instances might be quoted of spring waters which act with inconvenient or dangerous rapidity on lead. But it is hardly worth while mentioning more than one or two of these, because the nature of the waters has been seldom described.

A striking example was related by Dr. Wall of Worcester. A family in that town, consisting of the parents and twenty-one children, were constantly liable to stomach and bowel complaints; and eight of the children and both parents died in consequence. Their house being sold after their death, the purchaser found it necessary to repair the pump; because the cylinder and cistern were riddled with holes and as thin as a sieve. The plumber who renewed it informed Dr. Wall that he had repaired it several times before, and in particular had done so not four years before the former occupant died.[^[1248]] The nature of the water was not determined. Most of the water around Worcester is very hard; but this will not account for its operation in the instance now described.

Another incident of the same kind, but hardly so unequivocal in its circumstances, was related in 1823 by Dr. Yeats of Tunbridge. A plumber undertook to supply that town with water for domestic purposes, and in 1814 laid a course of leaden pipes for a quarter of a mile. In the subsequent year many cases of lead colic occurred among the inhabitants who were supplied by those pipes; and one lady particularly, who was a great water-drinker, lost the use of her limbs for some months. The inhabitants naturally became alarmed; iron pipes were substituted; and no case of colic appeared afterwards. Mr. Brande analyzed the water which had passed through the pipes and detected lead in it, while at the same time none could be detected at the source.[^[1249]] Some uncertainty was supposed to have been thrown over these statements by the analytic researches of Drs. Thomson, Scudamore, and Prout, and Mr. Children.[^[1250]] But water like that in question can scarce fail to act powerfully on lead in favourable circumstances; for according to the analysis of Dr. Thomson it is extremely pure, as it contains only a 38,000th part of saline matter, three-fourths of which are a feebly protecting salt, the muriate of soda.[^[1251]] I am satisfied, therefore, from my experiments, and the facts which follow, that no such water could be safely conveyed through new lead pipes; and that it would be dangerous even to keep it long in a lead cistern. It is difficult to account for the failure of the gentlemen above mentioned to find lead in the water, except by supposing that they had analyzed what had been exposed for some time to the air, and deposited its oxide of lead in the form of carbonate.

Since my attention was first turned to this subject, the three following incidents have occurred to me, which show the danger of conveying very pure water in long lead pipes. 1. A gentleman in Dumfries-shire resolved to bring to his house in leaden pipes the water of a fine spring on his estate, from a distance of three-quarters of a mile. As I happened to visit him at the time, I took the opportunity of examining the action of a tumbler of the water on fresh cut lead, and could not remark any perceptible effect in fourteen days. It appeared to me, therefore, that the water might be safely conveyed in lead pipes; and they were laid accordingly. No sooner, however, did the water come into use in the family, than it was observed to present a general white haze, and the glass decanters in daily use acquired a manifest white, pearly incrustation. On examining the cistern, the surface of the water, as well as that of the cistern itself, where in contact with it, was found completely white, as if coated with paint; and the water taken directly from the pipe, though transparent at first, became hazy and white when heated or left some hours exposed to the air. On afterwards analyzing the water direct from the spring, I found it of very unusual purity; as it contained scarcely a 22,000th of solid ingredients, which were sulphates, muriates, and carbonates. The reader can be at no loss to perceive why the experiment with a few sticks of lead in a tumbler was not a correct representation of what was subsequently to go on in the pipes: in fact, as the pipes were 4000 feet long, and three-fourths of an inch in diameter, each portion of water may be considered as passing successively over no less than 784 square feet of lead before being discharged. The remedy employed in this case will be mentioned presently [p. [415]]. 2. A gentleman in Banffshire introduced a fine spring into his house from a distance of three-quarters of a mile by means of a lead pipe. Two years and a half afterwards he was attacked with stomach complaints, obstinate constipation, and severe colic, for which he was under medical treatment for three months, with only partial and temporary relief. At last on leaving home and repairing to Edinburgh, he soon got quite well. Two other members of his family were similarly, but more slightly affected. On returning home some time afterwards, the same symptoms began to show themselves; but he had not been many weeks there, when his attention was accidentally drawn to a notice of my experiments, and of the last case, in Chambers’s Journal. He then saw that a white film lined the inside of the water-bottle in his dressing-room; and the water was declared by a chemist to contain lead. I lately had an opportunity of analyzing the water, and found it to contain only a 16,500th of solid matter, the principal salt being chloride of sodium, and the others being sulphates of magnesia and lime, with very little carbonate. This, therefore, was exactly a case in which action upon lead might have been anticipated, as the principal proportion of the very small quantity of saline matter present was a feebly protective salt. 3. The third instance occurred at a country residence of Lord Aberdeen. Mr. Johnston, surgeon at Peterhead, being called to visit the housekeeper, found her affected with vomiting, constipation, acute pain at the pit of the stomach, retraction of the navel, and great feebleness. Little improvement was effected in three days, when Mr. Johnston, astonished at this, and reflecting on the cause, suddenly was attracted by the appearance of a silvery film on the inside of his patient’s water-bottle, and recollected at the same time my narrative of the Dumfries-shire case. He then perceived that the disease was lead-colic, treated it accordingly, and slowly accomplished a cure. The housekeeper’s niece, a young girl who had resided only a few weeks with her, and who was the only other individual that had lived in the house above a few days together for more than a year before, had begun also to suffer from the premonitory symptoms. About twelve months before this incident happened, a spring of water, which had been analyzed and pronounced extremely pure, was brought to the house in a lead pipe; and the housekeeper had used this water for eight months before she took ill. Mr. Johnston found that the water issued from the pipe was quite clear, but that a white silvery film formed on its surface under exposure to the air; and he ascertained that the first-drawn water contained lead in solution, and that the film was carbonate of lead. I had an opportunity of analyzing the water, which proved to be by no means very pure, as it contained a 4460th of solids. But as the solid matter consisted almost entirely of chlorides, namely, in a great measure of chloride of sodium and a very little of the chlorides of magnesium and calcium, as there was no carbonate present, and the sulphates constituted only a 32,000th of the water,—it is plain from the principles formerly laid down that the action which took place was to be anticipated from the nature of the spring.[^[1252]]

For other instances of the corrosive action of spring water on lead the reader may refer to Dr. Lambe’s treatise. Dr. Lambe was led by his researches to imagine that no spring water whatever was destitute of this property in a dangerous degree. This wide conclusion is not supported by valid facts. Yet his work contains several accurative and instructive examples of the action in question. Thus among other instances he mentions that he had found the water of Warwick to act on lead with great rapidity, and once saw holes and furrows in a cistern there, which was the second that had been used in the course of ten years.[^[1253]] Sir G. Baker, in a letter to Dr. Heberden, has related another striking instance of the same kind. Lord Ashburnham’s house in Sussex was supplied from some distance with water, which was conveyed in leaden pipes. The servants being often affected with colic, which had even proved fatal to some of them, the water was carefully examined, and found to contain lead. The solvent power of the water was ascribed to its containing an unusual quantity of carbonic acid gas.[^[1254]] This may be doubted.

In the course of the preceding remarks, allusion has been made to the danger of keeping the same portion of water for a length of time in leaden cisterns, if it has the power of acting on lead even in a trifling degree. The following illustrations deserve particular notice.

It was mentioned in p. [409], as the result of experiments on the small scale, that although the water of Edinburgh does not contract a sensible impregnation of lead on remaining a few days in contact with it, yet a sufficient action ensues in the course of a few months, to show that it might be dangerous to keep that water long in a lead cistern. After coming to this conclusion, I had an opportunity of verifying it on a large scale. A cistern in my laboratory in the University having been left undisturbed for four or five months with about six inches of water in it, I found so large a quantity of pearly crystals lying loose on the cistern and diffused through the water, that when the whole was shaken up and transferred to a glass vessel, the water appeared quite opaque. Mérat observes that at the laboratory of the Medical Faculty of Paris there was procured by evaporating six loads, or probably about 1000 pounds of water, which had been kept two months in a leaden pneumatic trough, no less than two ounces of finely crystallized carbonate of lead.[^[1255]] Water in such circumstances has proved eminently poisonous. Thus, the crew of an East India packet having been put on short allowance of water, in consequence of being delayed by contrary winds, the men got their share each in a bottle; but the officers united their shares and kept it all in a lead cistern. In three weeks all the officers began to suffer from stomach and bowel complaints, and had the lead colic for six weeks; while the men continued to enjoy good health. The surgeon detected lead in a tumbler of water without the process of concentration, by adding to it the sulphuret of potass.[^[1256]] A similar accident has been briefly alluded to by Van Swieten. He mentions, that he was acquainted with a family who were all attacked with colica pictonum in consequence of using for culinary purposes water collected in a large leaden cistern and kept there for a long time.[^[1257]] The composition of the water has not been mentioned in any of these instances; but the water of Paris is so strongly impregnated with calcareous salts, that in ordinary circumstances its action on lead must be trifling.

It was probably from confounding the consequences of keeping the same water long in a lead cistern with the action in ordinary circumstances, that Dr. Lambe was led into the error of supposing that all spring waters whatever act on lead so powerfully, as to render it in his opinion advisable to abandon the use of this metal in the fabrication of pipes and cisterns. It must be admitted, however, that in all likelihood many waters will contain a trace of lead, without being kept more than the usual time in the pipe or cistern. For Dr. Lambe’s results correspond to a certain extent with the more recent and accurate researches of Dr. Thomson, who mentions many instances where a faint trace of lead was found in the residue of the evaporation of a large quantity of spring water by himself, as well as by Dr. Dalton, Dr. Wollaston, and Mr. Children.[^[1258]] But, as Dr. Thomson properly adds, when the quantity does not exceed a 600,000th or a millionth part of the water, as in these instances, it is ridiculous to imagine that any harm can result to man from the constant use of it for domestic purposes.

Another fact of some practical consequence, which flows from the experimental conclusions stated above is, that although it may be perfectly safe to keep some waters in leaden cisterns, it may be very unsafe to use covers of this metal, because the water which condenses on the covers must be considered as pure as distilled water. It has been found that white lead forms in much larger quantity on the inside of the covers of cisterns than on the cisterns themselves, where both are constructed of lead. A remarkable illustration of this is mentioned in a paper read before the Academy of Sciences at Paris in 1788 by the Comte de Milly. About a year after getting two leaden cisterns erected in his house, to keep the water of the Seine for general domestic purposes, he was attacked with severe and obstinate colic; which led him to examine his cisterns. He found that the sides, where they were occasionally left exposed by the subsidence of the water, and more especially the leaden cover, were lined with a white liquid, which was constantly dropping from the lid into the cistern, like the drops in caverns where stalactites are formed. The water was in consequence so strongly impregnated with lead as to give a dark precipitate with liver of sulphur.[^[1259]] The reason of this occurrence is, that the water in the cistern is a solution of preventive salts, but what reaches the lid is in a manner distilled. In Edinburgh the lids of the cisterns are invariably made of wood, whether on account of its superior cheapness merely, or because a leaden cover had been found perishable, I have not been able to discover.

It may be well to conclude these remarks on the action of spring waters on lead with a general summary of the chief circumstances to be adverted to in using lead for keeping or conveying water; to which may be added a few hints for preventing action where it is found to have taken place.

The general results of the preceding inquiries are that rain or snow-water for culinary use should not be collected from leaden roofs, nor preserved nor conveyed in lead;—that the same rule applies to spring waters of unusual purity, where for example the saline impregnation does not exceed a 15,000th of the water;—that spring water which contains a 10,000th or 12,000th of salts may be safely conveyed in lead pipes, if the salts in the water be chiefly carbonates and sulphates;—that lead pipes cannot be safely used, even where the water contains a 4000th of saline matter, if this consist chiefly of muriates;—that spring water, even though it contain a large proportion of salts, should not be kept for a long period in contact with lead;—and that cisterns should not be covered with lids of this metal.

Where action is observed to take place in the instance of particular waters, it may in some cases be impossible to prevent it by any attainable means. But the inquiries detailed above suggest two modes by which a remedy may be generally found. It appears that, where a crust of carbonate is allowed to form slowly and quietly on the surface of lead, even distilled water ceases to have any material action; and that the action is reduced almost to nothing if a crust be thus formed in a solution containing a minute quantity of some powerfully protecting salt, such as phosphate of soda. It appears to me then that a remedy may be often found in the instance of unusually pure spring waters—either by leaving the new pipes filled with the water for a few months, care being taken not draw any water from them in the interval,—or perhaps even more effectually by filling the pipes for a similar period with a solution containing about a 25,000th of phosphate of soda. I had determined to try the latter plan with the pipes in the Dumfries-shire case mentioned above, but recommended that in the first instance the pipes should be left for a few months full of the water of the spring, and the stop-cocks kept carefully shut; and on this being done for three or four months, it was found that the water afterwards passed with scarcely any impregnation of lead, and what little was contracted at first gradually diminished in the course of time.—Probably neither of these methods will be of more than temporary use, when the chief or only salt present is chloride of sodium, even though the proportion be considerable. Both plans seemed to answer for a time in the instance which occurred at Lord Aberdeen’s (p. [411]); but after a while the action recommenced, probably owing to the deposited carbonate being slowly dissolved. At the time of publication of my paper in the Transactions of the Royal Society of Edinburgh, the cure appeared complete, and was there represented to be so.

I should add that an effectual remedy has been lately introduced by a patent invention for covering lead pipes both externally and internally with a thin coating of tin.

In the remarks now made on the action of water on lead no account has been taken of the effect of the galvanic fluid in promoting it. This, however, is a most important co-operating agent, or rather perhaps it ought to be considered a distinct power; for it acts with energy where water alone acts least, namely, when there is saline matter in solution, because then a galvanic current of greater force is excited. In general it is necessary that two different metals be present in the water before galvanic action be excited; but a very slight difference may be sufficient. For example, it seems enough that the lead contain here and there impurities, constituting alloys slightly different from the general mass of the pipe or cistern. It is probable that galvanic action may be thus excited by the joinings being soldered with the usual mixture of lead and the more fusible metals. At least I have seen pipes deeply corroded externally, when made of sheets of lead rolled and soldered; and the action was deepest on each side of the solder, which had itself entirely escaped corrosion. Even inequalities in the composition of the lead may have the same effect. Sheet lead long exposed to air or water is sometimes observed to be corroded in particular spots; and these will always be found in the neighbourhood of parts of the metal differing in colour, hardness or texture from the general mass. I have not analyzed such spots; but I conceive the supposition now made is exceedingly probable, and supplies a ready explanation of the corrosion. Similar effects may arise simply from fragments of other metals lying long in contact with the lead. They may also arise from portions of mortar being allowed to lie on the lead; but the action here is not galvanic.

I have no doubt that many of the instances of unusually rapid corrosion of lead by water, such as that mentioned by Dr. Wall [p. [410]] are really owing, not to the simple action of water, but to an action excited obscurely in one or other of the ways now mentioned.

Of the Action of Acidulous Fluids on Lead and its Oxide.

Water acidulated with various acids acts on lead with different degrees of rapidity.

The effect of acidulation with carbonic acid has not yet been accurately ascertained. The effect of sulphuric acid is peculiar. Distilled water feebly acidulated with that acid acts much less rapidly on lead than when quite pure. Thus I have found that, if it contained a 4000th or even only a 7000th of sulphuric acid, fifty grains of lead kept in it for thirty-two days gained a seventh or a twelfth of a grain in weight, and were covered with beautiful crystals of sulphate of lead. A minute trace of lead could be detected in the water. Hydrochloric acid is somewhat more active as a solvent. Distilled water containing a 3000th of that acid acquired in thirty-two days a sweetish taste, and yielded by evaporation a considerable quantity of muriate of lead, while the lead rods lost weight, and were covered with acicular crystals of the same salt.

It is much more important, however, to consider the effects of the vegetable acids on lead and its oxide, because their solvent power is a fruitful source of the accidental as well as intentional adulteration of many articles of food and drink.

Acetic acid in the form of common vinegar, even when much diluted, attacks and dissolves metallic lead, if by exposing the surface of the fluid to the air, a constant supply of oxygen be maintained to produce oxidation. The citric acid will attack it under the same circumstances, but acts more slowly. In a solution of five grains of citric acid in twenty-four parts or two drachms of water, three lead rods lost two grains in weight in nine weeks. The greater part of the citrate of lead separated slowly in white powdery crystals; but a small portion was dissolved by the excess of acid, and imparted to the fluid a pleasant sweetness. Tartaric acid acts much less energetically. In a comparative experiment with the last, the lead gained nearly half a grain in weight by acquiring a crystalline coat of tartrate of lead. But I could not detect any lead in solution; and there was no loose powder. The tartrate of lead is very sparingly soluble in an excess of its acid, so that a sweet taste cannot be communicated by it to a fluid acidulated with tartaric acid. Malic acid, according to MM. Chevallier and Ollivier, acts so quickly as a solvent, that if a solution be kept in a lead vessel for three hours, the metal may be detected in the fluid by any of its ordinary tests.[^[1260]]

The acids act with greater rapidity on the protoxide of lead than on the metal; and the presence of air is of course not required to enable them to effect its solution.

The solvent power of the acids is liable to be counteracted by various substances; the operation of which, however, has not been well ascertained. It appears that substances containing gallic acid or tannin throw down the lead; and on this account various adulterations which would otherwise take place are either prevented or corrected. It has been also ascertained by Proust, that the vegetable acids do not attack lead when it is alloyed with tin. For as the latter metal has a stronger attraction than the former for acids, no lead can be oxidated before the tin undergoes that change.[^[1261]]

From what has been said of the action of the vegetable acids, it follows that the preparation or preservation of articles of food and drink in leaden vessels is fraught with danger. For, if they contain a vegetable acid, more particularly the acetic, as many of them do, and if they are allowed to remain in the vessel for a moderate length of time, they will be apt to be impregnated with the metal. In this way lead has been often insidiously introduced into the food of man.

Thus milk has been poisoned by being kept in leaden troughs. An instance of the kind has been related by Dr. Darwin. A farmer’s daughter used to wipe the cream from the edge of the milk which was kept in leaden cisterns, and being fond of cream, had a habit of licking it from her finger. She was seized in consequence with the symptoms of lead colic, afterwards with paralytic weakness of the hands, and she died of general exhaustion.[^[1262]] The circumstances under which the lead is acted on have not been carefully examined. It appears to be sometimes used with safety. It will of course be dissolved, if the milk should become sour.

Rum has been also supposed to be sometimes adulterated with lead by being left in contact with the metal. The dry belly-ache of the West Indies, which appears to be the same disease with the lead colic, has been ascribed by some to the same cause. But on this subject precise information is still wanted. Dr. J. Hunter has stated, that an epidemic colic, which attacked three of our regiments in Jamaica during the years 1781 and 1782, and which seized almost every man of them, was traced by him to the presence of lead in the rum; and he endeavours to show that the spirit might dissolve the lead in passing through the leaden worms of the distilling apparatus.[^[1263]] He adds in another work, that, according to information communicated by Dr. Franklin, the legislature of Massachusetts passed an act in 1723, prohibiting the use of leaden still-heads and worms in the distillation of spirituous liquors.[^[1264]] It is certain that rum has been often impregnated with lead; but it is by no means clear that Dr. Hunter has successfully accounted for the mode in which the adulteration is effected.

Wine has been accidentally impregnated in like manner, in consequence of the bottles having been rinsed with shot, and some of the shot left behind. An interesting example of this has been related in the Philosophical Magazine. Severe abdominal symptoms were caused by a bottle of wine; and the cause was discovered to be the action of the wine on some shot in the bottom of the bottle. The shot had been so completely dissolved, that it crumbled when squeezed between the fingers.[^[1265]] The illness in this instance must have been owing to the arsenic contained in the shot, because the quantity of lead was hardly sufficient to excite violent symptoms.—At one time home-made British wines must have been frequently adulterated with lead, from the makers being ignorant of the dangerous nature of the adulteration. Sir G. Baker quotes the following receipt in a popular cookery book of his time: “To hinder wine from turning.—Put a pound of melted lead in fair water into your cask, pretty warm, and stop it close.”[^[1266]]

But by far the most remarkable adulteration of the kind now under review is that of cider. At one time a disease in every respect the same as the lead colic used to prevail in some of the south-west counties of England at the cider season; and it was generally ascribed, in consequence apparently of the opinion of Huxham, to the working people indulging too freely in their favourite beverage during the season of plenty. The subject, however, was carefully investigated in 1767 by Sir George Baker, who succeeded in proving, that the disease arose from the cider being impregnated with lead, sometimes designedly for the purpose of correcting its acescency when spoiled, but chiefly by accident, in consequence of the metal being used for various purposes in the construction of the cider-house apparatus. The substance of his researches is,—that a disease in all respects the same with the lead colic was in his time so prevalent in Devonshire as to have supplied 289 cases to the Exeter Hospital in five years, and 80 to the Bath Infirmary in a single season (1766); while, on the contrary, it was little, if at all, known in the adjoining counties of Gloucester, Worcester, and Hereford, although cider is there an equally common drink among all ranks:—that in the latter counties lead was seldom or never used in constructing the apparatus of the cider-houses, while in Devonshire it was used sometimes for lining the presses, but more commonly for fastening the iron cramps, and filling up the stone joinings of the grinding troughs, and for conveying the liquor from vessel to vessel:—that lead did not exist in the cider of Herefordshire, but might be detected both in the ripe cider, and more especially in the must, of Devonshire:—that from eighteen bottles of cider, a year in bottle, 4½ grains of metallic lead were procured.[^[1267]] The accuracy of these facts, and the soundness of the conclusions which Sir George Baker drew from them have been universally admitted; and lead is now, I believe, completely excluded from the cider apparatus.

Notwithstanding the notoriety of these facts, accidents from adulterated cider seem still to occur occasionally in France. So recently as 1841 a set of cases which presented the incipient symptoms of lead colic were traced by MM. Chevallier and Ollivier to cider having been adulterated with lead to the amount of nearly two grains and a half per quart, in consequence of a publican having kept his cider for two days in a vessel lined with lead.[^[1268]]

If lead is previously oxidated, the presence of vegetable acids in articles kept in contact with it is still more likely to give rise to a poisonous impregnation, than in the case of lead itself.

Of accidental adulterations of this kind the most important is that which arises from the action of vegetable acids on the glazing of earthenware. This glaze is well known to contain generally a considerable quantity of oxide of lead, and in consequence is more or less easily dissolved by vegetable acids. A good example has been noticed by Dr. Beck.[^[1269]] A family in Massachusetts, consisting of eight persons, were all seized with spasmodic colic, obstinate costiveness, and vomiting; and the disease was satisfactorily traced to a store of stewed apples, which had been kept some months in an earthenware vessel and had corroded the lead glazing. Another interesting example has been described by Dr. Hohnbaum of Hildburghausen. A family of five persons were all violently affected for a long time with spasmodic colic, and some with partial palsy. After examining many articles of food, Dr. Hohnbaum at last found that the vinegar for dressing their salads was kept in a large earthenware vessel capable of holding eight or ten quarts, and glazed with lead; that an ounce of vinegar remaining in the vessel contained no less than nine grains of lead; and that the whole glazing of the vessel was completely dissolved.[^[1270]] Accidents like this appear from the statements of the same author to have been common in Germany not long ago. Luzuriaga attributes the great prevalence of colic in Madrid and the neighbourhood to the general use in the kitchen of earthenware glazed with lead.[^[1271]] Jacob imputes it to the same cause.[^[1272]] But others have doubted the accuracy of this explanation.

The effect of acids on lead glazing appears to be variable. Sometimes they hardly act on it at all.[^[1273]] The difference probably depends on differences in the composition of the glaze. Gmelin says, that if there is little oxide of lead present, acids and fat do not corrode it; but that potters often use too much, to render the glaze more fusible; and that then it is easily corroded.[^[1274]] Westrumb states, that, if the lead glaze is thoroughly vitrified and not cracked, the strongest acids do not attack it.[^[1275]] Farther experiments are still required to elucidate this subject.

It is not, however, by accident only that the food or drink of man is subject to be poisoned with lead. Many articles are adulterated with it designedly for a variety of purposes. These adulterations it is necessary for the medical jurist to study.

No kind of adulteration with lead is more common than that of wine; which, when too acid and harsh from the first, or rendered acescent by decay, may be materially improved in taste by the addition of litharge.

The practice of correcting unsound wines in this way seems to have been well known at an early period. Betwixt the years 1498 and 1577, various decrees were passed against it by the German emperors; and in some provinces the crime was even punished capitally.[^[1276]] For some time afterwards the dangerous effects of the practice appear to have been lost sight of in Germany. But towards the close of the seventeenth century, the attention of physicians and legislators in that country was pointedly directed to the subject by various writers in the Acta Germanica.[^[1277]] The same practice has been long prevalent in France. The famous endemic colic of Poitou, which appeared in 1572, and raged for sixty or seventy years, has been with justice ascribed in modern times to the adulteration of wine with lead, and has given to the lead colic its scientific name of colica pictonum. More recently, the practice became exceedingly prevalent in Paris. About the year 1750, the farmers-general found that for some years before that, 30,000 hogsheads of sour wine were annually brought into Paris for the alleged purpose of making vinegar, while the previous yearly imports did not exceed 1200. An inquiry was accordingly set on foot; which led to the discovery, that the vinegar merchants corrected the sour wines with litharge, and thus made them marketable.[^[1278]] Notwithstanding the active system of medical police in the French capital, the crime is not yet eradicated. Indeed the small tart wines used so abundantly there by all ranks, hold out great encouragement and facilities to its perpetration.

The process employed for correcting the acescency of wine is not precisely known. Some wines are easily corrected; Mérat found that a bottle of harsh wine, which had a sharp, bitterish, rather acrid taste, took up in forty-eight hours twelve grains of litharge, and became palatable.[^[1279]] With other wines this simple method will not answer, because the colour is destroyed, and a taste is substituted which has no resemblance to that of the genuine wine. Thus Orfila remarked, that Burgundy, neutralized with litharge, acquired a saccharine taste and became pale-red, because the insoluble salts of lead which were formed, combined with and removed the colouring matter.[^[1280]] On the whole, it is probable that the adulteration of wine with lead can only be practised with success on the common tart kinds, such as those used by the lower orders on the continent.

Some excellent observations have been published on this subject by Fourcroy. In order to render what he has said intelligible, it is necessary to premise, that in the course of the fermentation of wine, the bitartrate of potass, which accelerates the conversion of the sugar of the fruit into alcohol, is itself partly converted into malic acid; that in sound wine, therefore, there is a mixture of tartaric and malic acids; but that if the malic acid originally existed in the fruit in too great abundance, the fermentation of the sugar is imperfect, and the wine is consequently both too acid and too weak; and lastly, that all wines, if neglected, are apt to ferment too much, in consequence of which they pass the vinous stage of fermentation, and become impregnated with acetic acid.[^[1281]]

Now Fourcroy found that the oxide and other preparations of lead correct acescency and harshness in wines, not so much by throwing down the acids, as by combining with them in solution, and imparting to the liquor the peculiar sweetness of lead. Hence tart wines, which owe their acidity to too great a proportion of tartaric acid or bitartrate of potass, cannot be improved by adulteration with oxide of lead. For the bitartrate of potass cannot act at all as a solvent on the oxides or carbonate of lead, and even pure tartaric acid takes up so little, that wine containing it, could not acquire the sweet taste which is the purpose of the adulteration. This statement I have confirmed. But the case is very different when the wine contains acetic acid, the presence of which is the general cause of spoiling or acidity. For Fourcroy remarked, that acetic acid dissolves not only oxide and carbonate of lead, but likewise the tartrate, notwithstanding its great insolubility in water or in its own acid. Hence the presence of tartaric acid in a wine spoiled by co-existence of the acetic, will not prevent the liquor from taking up oxide of lead in sufficient quantity to acquire an improved taste and flavour. Nay, an obvious mode of correcting excessive acidity, produced by too much tartaric acid, is to add tartaric acid, and then to treat the mixture with oxide of lead. Fourcroy farther thinks, that the malic acid possesses the same solvent power as the acetic over tartrate of lead, and that its presence may therefore be the reason why some tart wines, which do not contain the acetic acid, become nevertheless impregnated with the poison. The solvent power of acetic acid is increased by the presence of other vegetable principles in the wine.[^[1282]] I may add, that I have found the citric acid to possess the same property with the acetic and malic acids. It dissolves so much of the tartrate of lead as to acquire a pleasant sweetness, unmixed with metallic astringency.

The practice of adulterating wine with lead does not seem to have been ever pursued to any material extent in Britain. Home-made wines may be adulterated in this way, as may be inferred from the receipt formerly quoted for preventing acescency. But I have never heard that any such adulteration has been suspected in the foreign wines usually drunk in this country. Considering, indeed, the nature of these wines, and the class of people who alone make use of them, it is not likely that adulteration with lead could be practised with success. If the foreign wines used in Britain should become acescent, lead could hardly restore their taste so thoroughly as to impose on the consumer.

Sometimes spirituous liquors and preserves have been adulterated with lead, in consequence of sugar of lead having been used to clarify them, or to render them colourless. Cadet de Gassicourt says it is a common practice in France to clarify honey and sugar of grapes, and to make brandy pale in this way; and M. Boudet has detected lead in many samples of these articles in Paris.[^[1283]] Hollands has likewise been poisoned in the same manner. Dr. Shearman mentions his having detected an extensive adulteration of smuggled Geneva by an excise officer, which had been sold and dispersed over an extensive tract of country, and which committed great ravages among the inhabitants.[^[1284]]

The adulterations hitherto noticed take place through means of the chemical action of the adulterated articles on lead or its oxide. Some other substances are occasionally contaminated by its compounds being merely mechanically mixed with them. There is no end to the number and variety of adulterations of this kind. But the following will serve as examples. Gaubius once detected an adulteration of butter with white lead at a time when it was very scarce in Flanders, owing to a dreadful mortality among cattle.[^[1285]] An instance of poisoning with lead, in consequence of cheese having been mixed with red lead, is mentioned in the Repertory of Arts.[^[1286]] This variety deserves to be remembered. Red lead was at one time a good deal used to communicate the peculiar reddish-yellow colour, which is supposed to characterize the finer qualities of certain kinds of English cheese. In the Transactions of the Medical Society of London, a singular instance has been related by Mr. Deering, of lead colic attacking a whole family, and proving fatal to two of them, in consequence of the insidious introduction of white lead into the body. Although the nature of the symptoms in the several cases left no doubt that lead was the cause of them, it was long before the source of the poison was discovered. Every vessel and article used in the kitchen was in vain examined; when at length it was discovered that the sugar used by the family had been taken from a barrel which had formerly contained white lead, and that, as the sugar from the centre of the barrel had been dug out, and given away to various friends, the outer part of it next the white lead was chiefly used by the family themselves.[^[1287]]

Process for detecting Lead in Organic Mixtures.

In the first place, a little nitric acid should be added to the suspected matter before filtration; for nitric acid redissolves any insoluble compound formed by the salts of lead with albumen and other animal principles, as well as some of those formed with vegetable principles; and consequently renders it more probable, that the poison will be detected in the first part of the analysis, if present at all.[^[1288]] This being done, sulphuretted-hydrogen gas is to be transmitted through the fluid part of the mixture; and if a dark-coloured precipitate is formed, the whole is to be boiled and filtered to collect the precipitate.

In order to ascertain that the precipitate positively contains lead, those who are accustomed to use the blowpipe may put the sulphuret into a little hole in a bit of charcoal, and reduce it by the fine point of a blowpipe-flame; when a single globule is procured, which is easily distinguished by its lustre and softness. A better process, for those not accustomed to the blowpipe, and perhaps a better test of the existence of lead in all circumstances, is to heat the sulphuret to redness in a tube, and to treat it with strong nitric acid, without heat or with the aid of a gentle heat only. The lead is thus dissolved without the sulphur being acted on. The solution is then to be diluted with water, filtered, evaporated to dryness, and gently heated to expel the excess of nitric acid. If the residue be dissolved in water, it will present the usual characters of a lead solution when subjected to the proper liquid tests. Of these the hydriodate of potass is to be preferred when the quantity is too small for trying more of them. But for this purpose care must be taken to expel all the excess of nitric acid, because an excess will strike a yellow colour with the test though lead be not present.

If the preceding process should not detect lead in the filtered part of the mixed fluid, then the insoluble matter left on the filter is to be incinerated, and the residuum dissolved in nitric acid, and tested as above. This branch, however, will be rarely required, if lead be present, because the precaution of adding nitric acid, previous to filtration, dissolves the lead from most of its compounds which are insoluble in water. The process of incineration in medico-legal analysis generally should be avoided if possible, as it is not easily managed by unpractised persons.—The present branch of the process of analysis will be particularly required for the contents of the stomach or vomited matter, when any sulphate or phosphate has been given as an antidote.

A process different from the preceding, and analogous to those for detecting copper and antimony in complex organic mixtures, has lately been proposed by Professor Orfila, especially for those cases in which lead is to be sought for in the textures of the body, where death is supposed to have been occasioned by it. The subject of analysis, such as the liver, spleen, or kidneys, being cut into small pieces, and boiled in distilled water, and the filtered decoction being evaporated to dryness, the extract is to be carbonized with nitric acid as directed under the head of copper (p. [357]); and care must be taken that the heat be not raised to redness, so as to inflame the mass. The residuum is then to be boiled with nitric acid; the solution being evaporated to dryness to expel the excess of acid, the saline matter left is to be redissolved and acted on by hydrosulphuric acid gas; and the sulphuret thus formed may be recognized by the means mentioned above.[^[1289]]

A question has been recently started, whether all the processes for detecting lead in the tissues of the human body are not rendered fallacious by the alleged existence of lead in the healthy animal textures. In the first place, however, it is doubtful, as will be seen presently, whether lead ever exists naturally in the animal organs. But besides, the fallacy, if a real one, is obviated by the process of Orfila; who states that lead, naturally combined in the animal tissues, cannot be indicated by his method, if the animal matter be charred by nitric acid without deflagration. And farther, in regard to the tissues of the stomach in cases of acute poisoning with the preparations of lead, it appears that in most instances there may be seen on the villous coat little white points, which are blackened by hydrosulphuric acid, a phenomenon never occasioned by lead naturally contained in the substance of the membrane. [See p. [439].]

Section II.—Of the Action of Lead and the Symptoms it excites in Man.

The effects of the preparations of lead on the body are very striking. They differ according to the rapidity with which it enters the system. Large doses of its soluble salts cause symptoms of irritant poisoning. The gradual introduction of any of its oxidated preparations in minute quantities brings on a peculiar and now well-known variety of colic, which is often followed by partial palsy, and in violent cases by apoplexy.

The physiological effects and mode of action of the soluble salts in irritating doses have been examined experimentally by Professor Orfila, M. Gaspard, Dr. Schloepfer, and Dr. Campbell. Their experiments agree in showing that these poisons have a direct irritating action, and a remote operation of an unknown kind; but the results obtained by different experimentalists differ as to some of the details. The acetate may be taken as a type of the whole genus.

Orfila found that it was hardly possible to bring dogs under the action of the acetate if swallowed in solution, because they speedily discharged it all by vomiting. But if the salt was given in powder in the dose of half an ounce, or if the solution was retained in the stomach by a ligature on the gullet, the symptoms produced were those of violent irritation in the first instance, succeeded by extreme weakness and death, sometimes in nine hours, more generally not till the second day or later. The appearances in the body were unnatural whiteness of the villous coat when death was rapid, and vascular redness when death was slower. The whiteness in the former case Orfila ascribes to chemical action. But as neither this appearance nor the redness in the latter case was considerable, while at the same time the symptoms were not those of continuous irritation, he was led to doubt whether the poison causes death in consequence of its irritant properties. And the phenomena observed by him when acetate of lead was injected into the jugular vein prove that death is owing to certain remote effects. Introduced through this channel thirteen grains killed a dog almost immediately, death being preceded by no other symptom except convulsive respiration; five grains killed another in five days, and the leading symptoms were weariness, languor, staggering, and slight convulsions, none of which symptoms appeared till the third day; and it is remarkable that in neither animal could he find any morbid appearance on dissection.[^[1290]] Mr. Blake states that large doses, such as a drachm, suddenly arrest the heart’s action; but that small doses of three grains, injected into the jugular vein, cause diminished action of that organ, and afterwards gorging and hepatization of the lungs; and that when injected backwards into the aorta from the axillary artery, this salt occasions obstruction of the capillary circulation, indicated by increased arterial pressure,—and then an action on the nervous system, producing insensibility, violent movements of the tail, and at last arrestment of the respiration. It may be inferred from Mr. Blake’s researches that lead obstructs both the systemic and pulmonary capillaries, that it acts powerfully on the nervous centre, and that it likewise depresses the heart’s action when the dose is large.[^[1291]]

The experiments of Gaspard coincide with those of Orfila in assigning considerable activity to the acetate of lead when it is directly introduced into the blood,—the quantity of two or four grains generally causing death in three or five days.[^[1292]] The experiments of Campbell farther show that death may be induced by applying it to a wound, and that the symptoms antecedent to death resemble those remarked by Orfila when it is injected into a vein.[^[1293]] But the two last experimentalists differ from Orfila in assigning to sugar of lead a property like that possessed by arsenic, of acting on the alimentary canal, even when applied to a wound, or directly introduced into the blood. For Campbell found the stomach corrugated and red, and the small intestines also vascular; while Gaspard not only observed analogous appearances after death, but even also witnessed all the symptoms of violent dysentery during life. In farther proof of the local irritating power of this poison, it may be added, that when sugar of lead was injected into the rectum Campbell found it to cause purging, tenesmus, itching of the anus, and great debility.

I have found that the nitrate of lead is powerfully irritant and corrosive in the dose of 400 grains. This quantity dissolved in four ounces of water killed a strong dog in sixteen hours, producing violent efforts to vomit and diarrhœa. And after death the whole inner membrane of the gullet and stomach, and the villi of the upper half of the small intestines, were uniformly white, brittle, and evidently disintegrated; and the mucous coat of the great intestines was bright red in parallel lines.

The only inquiries I have hitherto met with, which assign to lead in continued small doses the power of producing in animals the peculiar colic and palsy often produced by it in man are those of Schloepfer, related in his thesis on the effects of poisons when injected into the windpipe. He found that the acetate, introduced through this channel in successive doses of ten grains, brought on all the symptoms of colica pictonum, preceded by oppressed breathing, and ending fatally with palsy and convulsions in the course of three weeks.[^[1294]] More recently Dr. Wibmer, in the course of some experiments on the long-continued use of acetate and carbonate of lead, remarked weakness and stiffness of the limbs in dogs; and in the rabbit I have observed in the like circumstances gradually increasing weakness, ending in complete palsy of the fore-legs.

The compounds of lead seem to produce their effects on the animal body through the medium of absorption. At all events they are absorbed in the course of their action, and are diffused throughout the animal textures. Lead was long sought for with variable and dubious success in the fluids and solids of men and animals killed by it or labouring under its effects. But the late improvements in physiological science and chemical analysis have demonstrated, that it may always be detected in favourable circumstances in the liver and kidneys, often in the spleen and in the urine, and sometimes even in the muscles. Wibmer was the first who satisfactorily proved its presence. In dogs poisoned slowly by the acetate or carbonate of lead in frequent small doses, and dying with symptoms of lead-colic and palsy, he found the metal distinctly in the liver, muscles, and spinal cord, and more obscurely in the blood, by drying and deflagrating the animal matter with nitre, acting on the residue with nitric acid, neutralizing the solution, and testing it with hydrosulphuric acid, carbonate of potash, and iodide of potassium.[^[1295]] On repeating these experiments, I succeeded in detecting lead in very minute quantity in the lumbar and dorsal muscles of rabbits, but not any where else.[^[1296]] Professor Orfila has since frequently found lead, by means of his method of analysis described at page [424], in the kidneys, liver, and urine of animals which had taken large doses of acetate of lead, and once in the urine of a girl who had swallowed above an ounce of the acetate twenty-five hours before the urine was passed.[^[1297]] About the same time M. Ausset, under the directions of Lassaigne, detected lead largely in the blood and urine of a horse during life, and in the liver and kidneys after death.[^[1298]] Mr. Alfred Taylor found traces of it in the milk of a cow accidentally poisoned by carbonate of lead.[^[1299]] M. Tanquerel Desplanches says it has been detected by M. Devergie and himself in the palsied parts of persons who had died of colica pictonum;[^[1300]] and Dr. Budd observes, that Mr. Miller found lead in abundance in the paralysed extensors of the hand in a man who died in a London Hospital of the epileptic form of the effects of this poison.[^[1301]]

These facts seem to outweigh the negative results obtained by others. Nor are they invalidated by the alleged existence of lead in the healthy animal textures. For in the first place,—although M. Devergie says he has always found traces of lead in the substance of the stomach and intestines of men and women, who had not used preparations of lead or been in any way exposed to it,[^[1302]] and Professor Orfila confirmed these observations by also finding traces of lead in the alimentary canal under similar circumstances,[^[1303]]—the conclusion flowing from their researches is after all doubtful; for in a later inquiry MM. Danger and Flandin could not find any lead, unless it had been purposely introduced into the body.[^[1304]] And secondly,—Devergie adds to his remarks, that the quantity of lead he found in the textures and secretions of those who had died of lead-colic was far greater than in those who had not been exposed to lead preparations before death; and Orfila ascertained that the process by which he detects adventitious lead is incapable of indicating that which may be present naturally in the body.[^[1305]]

It is probable that all the preparations of lead are poisonous except the metal, and perhaps also the sulphuret. The experimentalists at the Veterinary School of Lyons found that nearly four ounces of the metal might be given to a dog without even vomiting being excited; and Orfila remarked that an ounce of carefully prepared sulphuret had as little effect.[^[1306]] The effects, which have been occasionally ascribed to lead-shot, and which will be mentioned by and by [see p. [435]], seem at variance with these experiments, but cannot outweigh such precise negative results. It is probable that irritant poisoning can be produced only by those compounds which are soluble, such as the acetate, subacetate, and nitrate. It appears indeed from the experiments of Orfila with the acetate and my own with the nitrate, that these compounds are true corrosives, and of no mean energy when given in large doses moderately diluted.

The insoluble compounds, such as the carbonate, red oxide and protoxide, possess little irritant power. The experimentalists of Lyons found litharge to be irritant in large doses of half an ounce.[^[1307]] Orfila gave dogs large doses of the red oxide and carbonate without observing any signs of irritation in the stomach. A case has been published of a young woman who swallowed accidentally an ounce and a half of the carbonate without any bad effect whatever either at the time or afterwards;[^[1308]] and Dr. Ogston of Aberdeen has informed me he met with a similar case, that of a girl who took an ounce with the view of destroying herself, but without sustaining any harm whatever. In a remarkable case, published by Mr. Cross of London, in which six drachms were taken accidentally by a pregnant female instead of magnesia, vomiting and violent colic were produced, and afterwards fainting, paralysis of the extensor muscles, and contraction of the flexors; all of which symptoms, however, after enduring without abatement till eight hours after the poison was swallowed, gradually disappeared under antidotes and laxatives. But such a case bears no great resemblance either to the acute or chronic form of poisoning with lead, and was probably hysterical.[^[1309]] Orfila has found that an ounce and a quarter of sulphate of lead had no effect whatever on a dog.[^[1310]] Mr. Taylor mentions a case where the chloride of lead caused vomiting, but no other ill consequence.[^[1311]] Dr. Cogswell found that three drachms of iodide of lead caused in a dog merely depression and weakness for a few days; but forty grains killed a rabbit in twelve days, with symptoms of exhaustion and constipation; and doses frequently repeated, to the amount of eleven drachms in eighteen days, killed a dog under symptoms nearly the same.[^[1312]]

It may be presumed that all the compounds of lead which are soluble in water or in the animal fluids may produce in favourable circumstances the lead colic and palsy. Dr. A. T. Thomson, indeed,[^[1313]] has endeavoured to show by some experiments, that the carbonate is the only compound of lead which possesses this singular power; and that if the acetate of lead produces similar effects, it is only because that salt usually contains an excess of oxide which becomes carbonate from the action of free carbonic acid in the stomach and other parts of animals, or because the salt is decomposed by double decomposition from the accidental presence of alkaline carbonates. It does not appear to me, however, that the researches of Dr. Thomson, taken along with the prior inquiries of other physiologists, will bear out this conclusion. The experiments of Wibmer in particular would seem to show that the carbonate is at least not more active than the acetate; nor does it appear probable that the small doses of acetate given by him, seldom exceeding two or three grains at a time, could yield any carbonate in the alimentary canal of a dog, where there is commonly much free muriatic acid. Farther, in many of the instances of lead colic related above as produced by cider, wine, and other acid substances acting on lead or its oxide, the acid must have been so greatly in excess, that it was scarcely possible that carbonate of lead could have been formed afterwards by any ordinary accident. And even supposing the carbonate to be more active than other compounds in occasioning colic and palsy, as Dr. Thomson’s inquiries would tend to show, the fact may be admitted without necessarily leading to the inference, that it is the only active compound of lead, or that other preparations must be converted into the carbonate before they can act as slow poisons. For the superior activity of the carbonate may be owing to the great obstinacy with which its impalpable powder adheres to moist membranous surfaces, and the consequent greater certainty of its ultimate absorption. It certainly appears at least but consistent with a general law, to which hitherto no undoubted exception has been found, that the carbonate must be dissolved before it can act constitutionally.

The symptoms observed in man from the preparations of lead are of three kinds. One class of symptoms indicate inflammation of the alimentary canal: another spasm of its muscles: and a third injury of the nervous system, sometimes apoplexy, more commonly palsy, and that almost always partial and incomplete. Each of these classes of symptoms may exist independently of the other two; but the last two are more commonly combined.

The irritant effects of large doses of the soluble salts of lead come first under consideration. Of these the acetate, or sugar of lead may be taken as an example.

Here it will, in the first instance, be observed that, according to the experiments mentioned above, the acetate of lead, though certainly an irritant poison, is not very energetic,—being much less so than the vulgar generally believe, and far inferior to most of the metallic poisons hitherto treated of. This farther appears from the experience of physicians as to its effects in medicinal doses. The acetate has been often given in pretty large doses in medical practice; and although it has sometimes excited colic when continued too long, ordinary irritation of the stomach seems to have been rarely observed. Mr. Daniell, in a paper on its effects as a remedy for mercurial salivation, states that he gave it in doses of ten grains three times a day, and that he never observed it to excite any other unpleasant symptom except slight colic, which seldom came on till after the fourth dose.[^[1314]] I have often given it in divided doses to the amount of eighteen grains daily for eight or ten days, without remarking any unpleasant symptom whatever, except once or twice slight colic. Van Swieten even mentions a case in which it was given to the amount of a drachm daily for ten days before it caused any material symptom.[^[1315]]

Yet facts are not wanting to prove that acetate of lead in an improper dose will produce violent and immediate effects. The symptoms are then either those of simple irritation, or more commonly those of inflammation united with the peculiar spasmodic colic of lead, and sometimes followed by convulsions and coma, or by local palsy.

In one of Sir George Baker’s essays there is an instance of immediate and violent symptoms having been caused by a drachm taken twice with a short interval between the doses. The subject was a soldier who took it in milk to cure a diarrhœa. Five hours after the first dose he was seized with pain in the bowels and a feeling of distension round the navel. After the second these symptoms became much more acute; and he was soon after seized with bilious vomiting, loss of speech, delirium, and profuse sweating, while the pulse fell down to 40. He recovered, however, with the aid of diluents and cathartics.[^[1316]]

A case which proved rapidly fatal has been related in a French journal. A drummer in a French regiment, who was much given to drinking, stole some Goulard’s extract, and drank it for wine. Neither the first symptoms nor the dose could be ascertained. On the second day he was affected with loss of appetite, paleness, costiveness, and excessive debility; on the third day he had severe and excessive colic, drawing in of the belly, loss of voice, cold sweats, locked jaw, and violent convulsions; and he expired before the evening of the same day. The morbid appearances will be mentioned in their proper place. Sugar of lead was detected in the stomach.[^[1317]]

In both these instances the disorder excited partook very much of the character of the spasmodic colic which is caused by the gradual introduction of lead into the body; and in the last the whole course of the man’s illness was very like that of the worst or most acute form of colica pictonum. But in another example which came under my own notice, the symptoms were more nearly those of ordinary irritation,—namely, vomiting, burning, and pricking pain in the throat, gullet, and stomach, with trifling colic subsequently; but the patient recovered in two or three days. The quantity taken was supposed to exceed a quarter of an ounce. So, too, in a case which occurred to M. Villeneuve of Paris, the symptoms were chiefly vomiting and purging, with faintness and some convulsions. His patient swallowed intentionally above an ounce of acetate of lead in solution. Sulphate of soda and sulphate of magnesia were given promptly as antidotes; in an hour the symptoms had abated materially; and next day she was well.[^[1318]] This was the case in which Orfila found lead in the urine. Of the same nature, also, are two cases briefly alluded to by Mr. Taylor, as having been caused in London in 1840 by Goulard’s extract. The subjects, who were children, were seized with vomiting, purging, and other symptoms like those of Asiatic cholera; and both died within thirty-six hours.[^[1319]]

In another instance, related by Mr. Iliff of London, where an ounce of the acetate was accidentally swallowed in solution, the symptoms were at first colic pains and vomiting, in the course of a few hours vomiting and tenderness, and, after these symptoms receded, a peculiar state of rigidity and numbness, which was not entirely removed for several days. In this case no remedies were used for three hours; and even two hours later, when the stomach-pump was resorted to on account of the slightness of the vomiting, lead was found in the first fluid withdrawn,—a new proof of the feeble action of acetate of lead, compared with some other metallic poisons.[^[1320]]

So much for the operation of the acetate of lead in large doses. Physicians, however, are much better acquainted with the effects of lead when introduced in the body continuously and insidiously in minute quantities. For all tradesmen who work much with its preparations are apt to suffer in this way, and many other persons have been brought under its action in consequence of articles of food and drink being impregnated with it. The disease which is thus induced may be divided into two distinct stages.

The first stage is an affection of the alimentary canal, the leading feature of which is violent and obstinate colic. This symptom at times begins abruptly during a state of sound health; but much more commonly it is ushered in by a deranged state of the stomach, not unlike common dyspepsia, seldom so severe as to excite alarm, and commonly imputed at first to a wrong cause. There is general uneasiness and depression, a dingy yellowish complexion, weakness and numbness in the limbs, a sweetish styptic taste and fetid breath, a slaty tint of the teeth and gums, with a blue line along the margin of the gums where they touch the teeth, a slow hard pulse, great emaciation, loss of appetite and tendency to indigestion. This state, which was first well characterized by Mr. Wilson[^[1321]] of Leadhills, and has lately been more fully described by M. Tanquerel,[^[1322]] is of great moment as apprizing the workman of the necessity of taking active measures for preventing the more formidable effects, which otherwise are sure to follow. Of the warning symptoms none is so invariable or so characteristic as the blue line along the edge of the gums, an appearance which was first noticed by Dr. Burton of St. George’s, London,[^[1323]] and has been since observed in every case of lead colic, whether impending or present.—If alarm be not taken in time, the obscure complaints hitherto mentioned become attended by and by with uneasy sensations in the stomach, stretching ere long throughout the whole belly. At the same time the stomach becomes irritable, and the food is rejected by vomiting. Cramps in the pit of the stomach then arise, and extend to the rest of the belly, till at length the complete colic paroxysm is formed. The pain is sometimes pretty constant; sometimes it ceases at intervals altogether; but much more commonly there are remissions rather than intermissions; and it is remarked that both the remissions and exacerbations are much longer than those of common colic. The pain is very generally, yet not invariably, relieved by pressure; even strong pressure seldom causes any uneasiness, provided it be not made on the epigastrium; nay, some patients have been known to bear, with relief to the paroxysms, the weight of two or three people standing on the belly.[^[1324]] The belly is almost always hard, the abdominal muscles being contracted: sometimes it is rather full, more commonly the reverse, and the navel is often drawn in so as almost to touch the spine. The bowels all the while are obstinately costive. Either there is no discharge from them at all; or scanty, knotty fæces are passed with much straining and pain. This state, long supposed to depend on spasm, is now known to arise on the contrary from paralysis, of the intestinal muscular coat. In a few instances diarrhœa takes the place of the opposite affection. The urine is commonly diminished. The saliva has been described as greater than natural in quantity and bluish in colour; but Dr. Burton says he did not observe a single instance of this in forty cases which he carefully examined. From the beginning, or more generally after a few hours or days, the limbs are racked with diffuse cutting pains; which, according to Tanquerel, affect chiefly the limbs, especially near the joints, are worst at night, are often attended with cramps, and are relieved by pressure. The aspect of the countenance is dull, anxious, and gloomy: in advanced cases the expression of gloomy anxiety exceeds that of almost all other diseases. It appears from the latest works on this disease published in France, and particularly from the able treatise of Mérat, that the pulse is rarely accelerated, but on the contrary often retarded.[^[1325]] This does not accord with the experience of some earlier writers;[^[1326]] and in the few cases I have seen in this city the pulse has been always frequent. It cannot be questioned, however, that, as Mérat states, fever is not essential. The skin has a dull, dirty, cadaverous appearance, is often, though not always hot, and in either case is bedewed with irregular, clammy, cold perspiration.

This, the first stage of colica pictonum, may end in three ways. In the first place, the patient may recover at once from it as from an ordinary colic; and it is consolatory to know, that a first attack, taken under timely management, is for the most part easily made to terminate in that favourable manner. In such circumstances it rarely endures beyond eight days. But it is exceedingly apt to recur, if, for example, the patient expose himself to what in ordinary circumstances would cause merely a common colic or diarrhœa; and if he returns to a trade which exposes him again to the poison of lead, the disease is sure to recur sooner or later, and repeatedly, unless he observes the greatest precautions. In one or other of these returns, sometimes even in the first attack, the colic is not succeeded by complete recovery, but gives place to another more obstinate and more alarming disease. This secondary affection is of two sorts. One, which occurs chiefly in fatal cases, is a species of apoplexy. The other, which does not of itself prove fatal, is partial palsy.

In violent and neglected cases of colica pictonum, the colic becomes attended in a few days with giddiness, great debility, torpor, and sometimes delirium; as the torpor advances the pains in the belly and limbs abate; at length the patient becomes convulsed and comatose, from which state very few recover. Tanquerel, who is unnecessarily minute in subdividing the various affections produced by the poison of lead, distinguishes four kinds of affections of the head, coma, epilepsy, delirium, and a combination of all these.[^[1327]] A very rare termination allied to that now described is sudden death during the colic stage, without any symptom which would lead one to suspect its approach. A case of this kind has been related by M. Louis. His patient, five minutes after talking to the attendant of his ward, was found at his bedside in the agony of death; and no cause for so sudden a death could be found on dissection.[^[1328]] Somewhat similar was a case which occurred in 1838 at the hospital of La Charité at Paris. A man labouring for three days severely under the colic stage of the disease, began to breathe stertorously soon after straining at stool, and died in three hours.[^[1329]] In a case which occurred to Dr. Elliotson death was owing to concomitant perforation of the stomach, a concurrence which was probably accidental, but which was also once observed by Dr. Copland.[^[1330]]

In cases, on the other hand, which have not been neglected, and particularly when the attack is not the first, the departure of the colic often leaves the patient in a state of extreme debility, which by and by is found to be a true partial palsy, more or less complete. This affection is sometimes present before the colic departs, but is apt to escape notice till the pain abates. Occasionally it supervenes on a sudden, but more generally it is preceded by a sense of weariness, numbness and tremor of the parts. The palsy is of a peculiar kind. It affects chiefly the upper extremities, and is attended with excessive muscular emaciation. The loss of power and substance is most remarkable in the muscles which supply the thumb and fingers; and in every case which I have seen the extensors suffered more than the flexors. The paralysis is hardly ever complete, except perhaps in the extensors of the fingers. When it is considerable, the position of the hands is almost characteristic of the disease. The hands are constantly bent, except when the arms hang straight down by the side; they dangle loosely when the patient moves; he cannot extend them, and raises one arm with the aid of the other. The palsy is attended, according to Tanquerel, with diminished heat in the parts, and feeble pulsation in the arteries which supply them. There is seldom any loss of sensation in the affected parts. But the paralysis sometimes affects the nerves of the other senses. Thus two cases of paralysis of the nerves of vision have been related by Dr. Alderson of Hull;[^[1331]] and Tanquerel says this affection is not uncommon in Paris, and is attended with dilated and immovable pupils. The latter author also once met with deafness in the same circumstances.—Patients affected with lead palsy usually complain of racking pains in the limbs and arms, digestion is feeble, and trivial causes renew the colic. From this deplorable condition it is still possible to restore the sufferer to health, chiefly by rigorous attention to regimen. But he too often dies in consequence of a fresh attack of colic as soon as he returns to his fatal trade.

The lead palsy, however, does not always come on in this regular manner. Sometimes the primary stage of colic is wanting, so that the wasting of the muscles and loss of power are the first symptoms. I have seen a characteristic example of the kind in a sailor who had been employed for a month in painting a vessel. He had great weakness and wasting of the arms and hands, particularly of the ball of the thumb; but except a tendency to indigestion, costiveness, and transient slight pain of the belly, he had suffered no previous disorder of the intestines. I have seen the paralytic affection confined to the extensors of one hand in a compositor, and Dr. Chowne met with a similar affection of both hands in a gas-fitter.[^[1332]] Dr. Bright observed palsy without colic in the case of a painter three times in the course of seven years.[^[1333]]—In like manner, according to Tanquerel, the neuralgic affection may occur severely without any precursory colic; and the same author has witnessed both coma and convulsions in the same circumstances.

Colica pictonum, with the collateral disorders specified above, is the only disease which has been distinctly traced to the operation of lead insidiously introduced into the body. But many other disorders have been ascribed to its agency. Boerhaave seems to have imagined that consumption might be so induced; and Dr. Lambe thought that to this cause may be traced the increased prevalence of “scrofula, phthisis, dropsy, chronic rheumatism, stomach complaints, hypochondriasis, and the host of nervous complaints which infest modern life.”[^[1334]] These conjectures are wholly destitute of foundation in fact.

In whatever form lead is habitually applied to the body, it is apt to bring on the train of symptoms mentioned above;—the inhalation of its fumes, the habitual contact of any of its compounds with the skin, the prolonged use of them internally as medicines, or externally as unguents and lotions, and the accidental introduction of them for a length of time with the food, may sooner or later equally induce colica pictonum.

Instances have occurred of colic being produced by the prolonged employment of the compounds of lead inwardly in medical practice. Such cases are so uncommon that it is evident some strong constitutional tendency must co-operate. But it is in vain to deny, as some do, that the medicinal employment of preparations of lead internally is unattended with any risk whatever of slow poisoning. Dr. Billing of Mulhausen relates a case of death, apparently from the comatose affection succeeding the colic stage of poisoning with lead, in the instance of a boy of fifteen, to whom he gave acetate of lead in gradually increasing doses for six weeks, till he took two grains daily.[^[1335]] Tanquerel met with a case of colic produced by 130 grains taken in fourteen days, and another occasioned by 149 grains in sixteen days.[^[1336]] Sir George Baker has mentioned similar instances.[^[1337]] It would even appear that metallic lead may have the same effect when taken inwardly. Thus Dr. Ruva of Cilavegno has related the case of a man who was violently attacked with the colic form of the effects of lead after taking six ounces of shot by direction of a quack for the cure of dyspepsia, and was seized again with the same symptoms six days afterwards on taking four ounces more. On the second occasion he had violent colic, great feebleness of the limbs, constant vomiting of any thing he swallowed, severe headache, and other analogous symptoms, of which he was not effectually cured for seven weeks.[^[1338]] A case somewhat similar, but less severe, has been described by Dr. Bruce.[^[1339]]—With regard to lead colic being excited by unguents and lotions applied to the surface of the body, Sir George Baker mentions a case of violent colic brought on by litharge ointment applied to the vagina; he adds that children have been thrown into convulsions by the same substance sprinkled on sores: and he quotes Zeller for a case where symptoms of poisoning were occasioned by sprinkling the axilla with it, as a cure for redness of the face.[^[1340]] Dr. Wall, in a letter to the preceding author, mentions his having seen the bowels affected by Goulard’s extract applied to ulcers; in another paper he has given two unequivocal cases, in one of which colic was brought on by saturnine lotions applied to a pustular disease, and in the other by immersing the legs twice a day for ten days in a bath of the solution of acetate of lead:[^[1341]] and lately Dr. Taufflieb of Barr observed lead colic to arise from the continued use of diachylon plaster during eleven weeks for dressing an extensive ulcer.[^[1342]] Such accidents are exceedingly rare, and some auxiliary cause must have favoured the operation of the poison in the cases now noticed; for every one knows that free use is made of lead unguents and lotions, yet we seldom hear of any bad consequences.—These cases, however, will probably remove the doubts which some entertain of the possibility of lead colic being induced by the application of the compounds of lead to the sound skin in those trades which compel the workmen to be constantly handling them. At the same time it must be admitted, that in all these trades there exists a more obvious and ready channel for the introduction of the poison; because the workmen are either exposed to breathe its fumes, or are apt to transfer its particles from the fingers into the stomach with their food.—Of all exposures none is more rapid and certain than breathing the vapours or dust of the preparations of lead. But for that very reason workmen who are so exposed seldom suffer; because the greatness of the risk has led to the discovery of means to avert it, and the openness of the danger renders it easy for the workmen to apply them. Tanquerel mentions a singular case of a woman who was attacked in consequence of the fine dust of white lead ascending through chinks in the floor from a room below, where a perfumer was in the practice of grinding and sifting that substance.[^[1343]]—It may be added that Dr. Otto of Copenhagen has published an extraordinary instance of fatal lead-colic, originating in the habitual use of Macuba snuff adulterated with twenty per cent. of red lead.[^[1344]]

To these observations on the various ways in which lead insidiously enters the system a few remarks may be added on the trades which expose workmen to its influence. The most accurate information on this subject is contained in the work of Mérat.

He places foremost in the list miners of lead. In this country miners are now rarely affected, because the frequency of colica pictonum among them formerly led their masters to study the subject, and to employ proper precautions for removing the danger. It has been stated by Dr. Percival, and is generally thought, that the whole workmen in lead mines are apt to be attacked with the colic,—those who dig the sulphuret as well as those who roast the ore.[^[1345]] If this idea were correct, it would be in contradiction with the general principle in toxicology, that the metals are not poisonous unless oxidated. But the opinion is in all probability founded on error; for, according to information communicated to me by Mr. Braid, and confirmed since by personal investigation, the workmen at Leadhills who dig and pulverize the ore, although liable to various diseases connected with their profession, and particularly to pectoral complaints, never have lead colic till they also work at the smelting furnaces. Next to miners may be ranked manufacturers of litharge, red-lead and white-lead. The workmen at these manufactories are exposed to inhale the fumes from the furnaces or the dust from the pulverizing mills. It has been chiefly among the workmen of a former white-lead manufactory in the neighbourhood of Edinburgh that I have had an opportunity of witnessing the lead colic. By a simple change the proprietor made in the process, and which will be mentioned presently, the disease was almost extirpated some years before the manufactory was given up.

Next in order, perhaps in the same class with colour-makers, are house-painters. The causes of their liability is the great quantity of the preparations of lead contained in the paints they use. It would appear that lead colic is most frequent among people of that trade in cities of the largest size. In Geneva, as I am informed by my friend Dr. C. Coindet of that place, colica pictonum is now almost unknown and never occurs among painters. In Edinburgh it is also little known among painters. A journeyman painter, a patient of mine in the Infirmary, had been seventeen years in the trade, and yet did not know what the painters’ colic or lead palsy meant. In London, according to the Dispensary reports, and in Paris, according to the tables of Mérat, many workmen of that trade suffer. I have been informed by an intelligent workman, once a patient of mine, who had been a journeyman painter both in London and Edinburgh, that the number of his acquaintances who had been affected with colic in the metropolis was incomparably greater than here. This man ascribed the difference to the working hours being more in the former place, so that the men had not leisure enough to make it worth their while to clean themselves carefully in the intervals. This appears a rational explanation. I do not know how the great prevalence of colic among painters in Paris is to be accounted for.

Plumbers, sheet-lead manufacturers, and lead-pipe makers, are also for obvious reasons apt to suffer; but as they are not necessarily exposed to the vapours of lead, and suffer only in consequence of handling it in the metallic form, it ought to be an easy matter to protect them. They themselves conceive that a very hazardous part of their occupation is the removing the melted lead from the melting pot, to make the sheets or pipes; but this operation cannot be dangerous if the melting pots are properly constructed.

A few cases of lead colic occur among glass-blowers, glaziers, and potters, who use the oxide of lead in their respective trades.

There are a few also among lapidaries and others, who use it for grinding and polishing, and among grocers and colourmen who sell its various preparations. Printers seldom suffer from the colic, but are generally thought liable to partial palsy of the hands, which is ascribed to frequent handling of the types. I have met with one case apparently of this nature.

Lead is not the only metal to which the power of inducing colica pictonum has been ascribed. Mérat has mentioned several instances of the disease occurring among brass-founders and other artizans who work with copper.[^[1346]] Tronchin quotes Scheuchzer for a set of well-marked cases in a convent of monks, where the malady was supposed to have been traced to all the utensils for preparing and keeping their food having been made of untinned copper.[^[1347]] The same author mentions two cases, one of which came under his immediate notice, where the apparent cause was the long-continued use of antimonial preparations internally.[^[1348]] Mérat likewise found a few iron-smiths and white-iron-smiths in the lists kept at one of the Parisian hospitals.[^[1349]] Chevallier alleges that colic occurs at times among money-changers at Paris, and others who constantly handle silver.[^[1350]] Cases have even been noticed by Mérat among varnishers, plasterers, quarrymen, stone-hewers, marble-workers, statuaries, saltpetre-makers;[^[1351]] and Tronchin enumerates among its causes the immoderate use of acid wine or of cider, checked perspiration, sea-scurvy, and melancholy. But the only substance besides lead, whose operation in producing colica pictonum has been traced with any degree of probability, is copper; and even among artizans who work with copper the disease is very rare. As to the other tradesmen mentioned by Mérat, it is so very uncommon among them, that we may safely impute it, when it does occur, to some other agent besides what the trade of the individual exposes him to; and in general the secret introduction of lead into the body may be presumed to be the real cause. Still, however, the connection of colica pictonum with other causes besides the poison of lead is upheld by so many facts, and is believed by so many authorities, that this disease cannot be safely assumed, even in its most characteristic form, as supplying undoubted evidence of the introduction of lead into the system. Dr. Burton thinks it will when the blue line at the edge of the gums is seen.

The work of Mérat contains some interesting numerical documents, illustrative of the trades which expose artisans to colica pictonum. They are derived from the lists kept at the hospital of La Charité in Paris, during the years 1776 and 1811. The total number of cases of colica pictonum in both years was 279. Of these, 241 were artisans whose trades exposed them to the poison of lead, namely, 148 painters, 28 plumbers, 16 potters, 15 porcelain-makers, 12 lapidaries, 9 colour-grinders, 3 glass-blowers, 2 glaziers, 2 toy-men, 2 shoemakers, a printer, a lead-miner, a leaf-beater, a shot-manufacturer. Of the remainder, 17 belonged to trades in which they were exposed to copper, namely, 7 button-makers, 5 brass-founders, 4 braziers, and a copper-turner. The remaining twenty-one were tradesmen, who worked little, or not at all with either metal, namely, 4 varnishers, 2 gilders, 2 locksmiths, a hatter, a saltpetre-maker, a winegrocer, a vine-dresser, a labourer, a distiller, a stone-cutter, a calciner,[^[1352]] a soldier, a house-servant, a waiter, and an attorney’s clerk.—Age or youth seems not to afford any protection against the poison. Of the 279 cases, 24 were under twenty, and among these were several painter-boys not above fifteen years old; 113 were between nineteen and thirty; 66 between twenty-nine and forty; 38 between thirty-nine and fifty; 28 between forty-nine and sixty; and 10 older than sixty. These proportions correspond pretty nearly with the relative number of workmen of similar ages.—Among the 279 cases fifteen died, or 5·4 per cent.

There seems to have lately been little or no diminution in the frequency of the disease in Paris. In 1833–4–5–6, there were treated in the hospitals 1541 cases, or 385 annually; of whom one in 39½ died. And in 1839–40–41 there were 761 cases, or 252 annually; of whom one in 24½ died. Of 302 cases in 1841 no fewer then 266 were from white-lead manufactories.[^[1353]]

Section III.—Of the Morbid Appearances caused by Lead.

The morbid appearances caused by poisoning with lead are in some respects peculiar.

In acute poisoning, from the irritant action of its soluble salts, as in the case of the drummer poisoned by Goulard’s extract, the lower end of the gullet, the whole stomach and duodenum, part of the jejunum, and the ascending and transverse colon, have been found much inflamed, and the villous coat of the stomach as if macerated. In Mr. Taylor’s two cases Dr. Bird found the villous coat of the stomach gray, but otherwise natural; and the intestines were much contracted.

The stomach in the first of these cases contained a reddish-brown, sweetish, styptic fluid, in which lead was detected by chemical analysis,[^[1354]]—an important medico-legal fact, since the man survived nearly three days. Some valuable observations have been made by Professor Orfila as to the presence of lead in the textures of the stomach in such instances. When small doses of acetate or nitrate of lead were administered to dogs and allowed to act for two hours only, the villous coat presented numerous streaks of white points, which contained lead, as hydrosulphuric acid blackened them. These points, though less distinct, were still visible, when the animals were allowed to live four days after the excess of salt had been removed; and even after seventeen days, although no such appearance remained, lead could still be detected in the tissues of the stomach.[^[1355]]

The blood in animals is sometimes altered. Dr. Campbell found it fluid. In a dog poisoned with litharge, the experimentalists of the Veterinary School at Lyons found it of a vermilion colour in the veins, and brighter than usual in the arteries.[^[1356]] Mitscherlich also found it unusually red and firmly coagulated.[^[1357]]

The appearances in the bodies of those who have died of the various forms of lead colic are different, and wholly unconnected with inflammation.

The valuable work of Mérat contains four inspections after death from the acute or comatose form of colica pictonum. The bodies were plump, muscular and fat. The alimentary canal was quite empty, and the colon much contracted,—in one to an extraordinary degree. The mucous coat of the alimentary canal was everywhere healthy. He therefore infers that the disease is an affection of the muscular coat only. It is a striking circumstance, and conformable with what will be afterwards established in regard to the true narcotics, that although both of the men died convulsed and comatose, no morbid appearance was visible within the head.[^[1358]] Another case, which confirms the foregoing facts, has been described by Mr. Deering. It was that of a lady who died convulsed after suffering in the usual manner, and in whose body no trace of disease could be detected any where.[^[1359]] Senac informed Tronchin that he had dissected above fifty cases of colica pictonum, and found no morbid appearances.[^[1360]] Schloepfer’s observations on animals are to the same effect. In rabbits which died of colica pictonum the great intestines were excessively contracted, but all the other organs of the body were healthy except the liver, which was dark and brittle.[^[1361]] Mitscherlich observed in his animals extravasation of blood into the intestines, also sometimes into the cavities of the pleura and peritoneum, and occasionally under the peritoneal covering of the kidneys.[^[1362]] The only instance I have met with where morbid appearances were found within the head, was in a case mentioned by Sir G. Baker, of a gentleman who died apoplectic after many attacks of colica pictonum, and in whom the brain was found unusually soft, and blood extravasated on its surface to the amount of an ounce.[^[1363]]

The appearances in those who have been long affected with the paralytic form of colica pictonum have been rarely observed in modern times. I am indebted to my late colleague, Dr. Duncan, Junior, for an account of the appearances in the intestinal canal of a plumber, who had been long and frequently afflicted with colica pictonum and its sequelæ. The intestines were dark, tender, and far advanced in putrefaction. The cardiac orifice of the stomach was so narrow that it would admit a goose-quill. The mesenteric glands were enlarged and hardened. The thoracic duct was surrounded by many large bodies like diseased glands, exactly of the colour of lead, and composed of organized cysts containing apparently an inorganic matter. The analysis of this matter was unfortunately neglected. The muscles in similar circumstances are much diseased. When the paralysis is not of long standing, it appears from the experiments of Schloepfer (whose animals survived about three weeks), that the whole muscular system becomes pale, bloodless, and flaccid. When the palsy is of long standing, this change increases so much, that the muscles in some parts, as in the arms and thumbs, acquire the colour and general aspect of white fibrous tissue. Some observations on the nature of these changes will be found in the essays of Sir G. Baker.[^[1364]] The facts are communicated by Mr. John Hunter. On examining the muscles of the arm and hand of a house-painter who was killed by an accident, Mr. Hunter found them all of a cream colour, and very opaque, their fibres distinct, and their texture unusually dry and tough. These alterations he at first imagined might have been the result merely of the palsy and consequent inactivity of the muscles, but on finding the same alterations produced by the direct action of sugar of lead on muscle, he inferred that the poison gradually effected a change either on the muscles directly, or on the blood which supplied them.

In a late elaborate inquiry into the pathology of lead-colic, M. Tanquerel has arrived at the conclusion, that “the pathological phenomena are not caused by anatomical changes cognisable by the senses,” and that such appearances as may be found are the effects, not the cause, of the disease.[^[1365]]

Section IV.—Of the Treatment of Poisoning with Lead.

The treatment of poisoning with lead, and the mode of protecting workmen from its influence, will now require a few remarks.

For the irritant form of poisoning, a safe and effectual antidote exists in any of the soluble alkaline or earthy sulphates. If none of these be at hand, then the alkaline carbonates may be given, particularly the bicarbonates, which are not so irritating as the carbonates. The phosphate of soda is also an excellent antidote. If the patient does not vomit, it will be right also to give an emetic of the sulphate of zinc. In other respects, the treatment does not differ from that of poisoning with the irritants generally.

Colica pictonum is usually treated in this country with great success by a practice much followed here in colic and diarrhœa of all kinds,—the conjunction of purgatives with anodynes. A full dose of a neutral laxative salt is given, and an hour afterwards a full dose of opium. Sometimes alvine discharges take place before the opium acts, more commonly not till its action is past, and occasionally not for a considerable time afterwards. But the pain and vomiting subside, the restlessness and irritability pass away, and the bowels return nearly or entirely to their natural condition. Sometimes it is necessary to repeat the practice. It is almost always successful. I have seldom seen the second dose fail to remove the colic, leaving the bowels at worst in a state of constipation. Dr. Alderson of Hull, who has had many opportunities of treating the workmen of a white-lead manufactory there, says powerful purgatives, such as croton-oil, are highly serviceable in severe cases, and are borne well notwithstanding the extreme debility often present.[^[1366]] M. Tanquerel says he has found this treatment more effectual in Paris than any other means.[^[1367]] When the pulse is full and strong, I have seen venesection premised with apparent advantage; in some instances it appeared to me to be called for by the flushing of the face and the violence of the spasms; and I have never seen it otherwise than a safe remedy, notwithstanding the fears expressed by Dr. Warren and others.[^[1368]]

The hospital of La Charité in Paris has long enjoyed a high reputation for the treatment of this disease. In the first place a decoction is given of half an ounce of senna in a pound of water, mixed with half an ounce of sulphate of magnesia and four ounces of the wine of antimony. Next day an ounce of sulphate of magnesia and three grains of tartar-emetic are administered in two pounds of infusion of cassia, to keep up the operation of the first laxative. In the evening a clyster is given, containing twelve ounces of wine and half as much oil. After this the patient is made to vomit with tartar-emetic, then drenched with ptisanes for several days, and the treatment is wound up with another dose of the first purgative succeeded by gentle anodynes. I am not aware of any particular advantage possessed by this complicated and tormenting method of cure, which is not equally possessed by the simpler plan pursued in Britain.

In 1831 M. Gendrin announced to the French Institute that he had found sulphuric acid to be at once the most effectual remedy, and the most certain preventive, for the injurious effects of lead; and he has subsequently spoken in strong terms of the utility of this treatment.[^[1369]] But the experience of others does not bear out his conclusions.[^[1370]]

Among the many other methods of cure that have been proposed for the primary stage of this disease, salivation by mercury deserves to be particularized. It appears to have been often used with success, the colic yielding as soon as ptyalism sets in.[^[1371]] If the case, however, is severe, there is no time to lose in waiting for the action of the mercury to commence.

The treatment in the advanced period of the disease, when palsy is the chief symptom remaining, depends almost entirely on regimen. The patient must for a time at least quit altogether his unlucky trade. He should be allowed the most generous food he can digest. He ought to take frequent gentle exercise in the open air, but never to fatigue. The hands being the most severely injured of the affected parts, and at the same time the most important to the workman, the practitioner’s attention should be directed peculiarly to the restoration of their muscular power. This appears to be most easily brought about by frictions, electricity, and regulated exercise, the hands being also supported in the intervals by splints extending from the elbows to the fingers. The dragging of the emaciated muscles by the weight of the dangling hands certainly seems to retard recovery.—Strychnia has also been repeatedly found of service in restoring muscular action. Tanquerel states that electricity and strychnia, but especially the latter, have appeared to him by far the most efficacious remedies both for muscular paralysis and for amaurosis.—In the head affections the best treatment consists in relying on nature and merely combating symptoms; and blood-letting is of no use, however much it may seem to be indicated by the coma and convulsions.

When a person has been once attacked with colica pictonum, he is more easily attacked again. Hence if he is young enough, he should, if possible, change his profession for one in which he is not brought into proximity with lead. Few, however, have it in their power to do so. The prophylaxis, therefore, or mode of preventing the influence of the poison, becomes a subject of great importance; and more particularly when we consider the vast number of workmen in different trades, whose safety it is intended to secure.

On this subject many useful instructions are laid down in the work of Mérat. He very properly sets out with insisting on the utmost regard being paid to cleanliness,—a point too much neglected by most artizans, and particularly by those to whom it is most necessary, the artizans who work with the metals. In proof of the importance of this rule, he observes he knew a potter, who contracted the lead colic early in life when he was accustomed to go about very dirty, but for thirty years after had not any return of it, in consequence simply of a scrupulous attention to cleanliness. In order to secure due cleanliness three points should be attended to. In the first place, the face and hands should be washed once a day at least, the mouth well rinsed, and the hair occasionally combed. Secondly, frequent bathing is of great consequence, both with a view to cleanliness and as a general tonic; so that masters should provide their workmen with sufficient means and opportunities for practising it. Lastly, the working clothes should be made, not of woollen, but of strong, compact linen, should be changed and washed at least once and still better twice a week, and should be worn as little as possible out of the workshop. While at work a cap of some light impervious material should always be worn.

Next to cleanliness, the most important article of the prophylaxis relates to the means for preventing the food being impregnated with lead. For this end it is essential that the workmen never take their meals in the workshop, and that before eating they wash their lips and hands with soap and water, and brush out all particles of dirt from the nails. It is also of moment that they breakfast before going to work in the morning.

Derangements of the digestive organs should be watched with great care. If they appear to arise from the poison of lead, the individual should leave off work with the very first symptom, and take a laxative. Habitual constipation should be provided against.

The nature of the diet of the workmen is of some consequence. It should be as far as possible of a nutritive and digestible kind. Mérat condemns in strong terms the small tart wines generally used by the lower ranks of his countrymen. They constitute a very poor drink for all artizans; and are peculiarly ill adapted for those who work with lead, because, besides being at times themselves adulterated with that poison, they are also apt to disorder the bowels by their acidity. Beer is infinitely preferable. Various articles of diet have been recommended as tending to impede the operation of the poison. Hoffmann recommends brandy, the efficacy of which few workmen will dispute. There is some reason for believing that the free use of fat and fatty articles of food is a preservative. Dehaen was informed by the proprietor and the physician of a lead mine in Styria, that the work-people were once very liable to colic and palsy, but that, after being told by a quack doctor to eat a good deal of fat, especially at breakfast, they were exempt for three years.[^[1372]] Another fact of the kind was communicated to Sir George Baker by a physician at Osterhoüt, near Breda. The village contained a great number of potters, among whom he did not witness a single case of lead colic in the course of fifteen years; and he attributes their immunity to their having lived much on cheese, butter, bacon, and other fatty kinds of food.[^[1373]] Mr. Wilson says, in his account of the colic at Leadhills in Lanarkshire, that English workmen, who live much on fat meat, suffer less than Scotchmen, who do not.[^[1374]]

Professor Liebig says that lead colic is unknown in all white-lead manufactories, where the workmen use as a beverage lemonade or sugar-water acidulated with sulphuric acid; and it was stated above that the same announcement has been made by Mr. Gendrin. This, however, is doubtful. The prophylactic effects of sulphuric acid have been denied in France by M. Tanquerel,[^[1375]] and M. Grisolle;[^[1376]] the latter of whom in particular says that no advantage whatever was derived from it at the white-lead manufactory of Clichy near Paris.

Some have likewise proposed as an additional preservative, that the exposed parts of the body should be anointed with oily or fatty matters. But Mérat maintains with some reason, that the lead will be thereby enabled to penetrate the cuticle more easily by friction and pressure.

The observance of the preceding rules will depend of course in a great measure on the intelligence and docility of the workmen. It would appear that particular care should be taken in hot weather, statistical facts having shown that three times as many workmen are attacked in Paris during the month of January as in July.[^[1377]]

Some other objects of much consequence are to be attained by the humanity and skill of the masters.

The workshop should be spacious, and both thoroughly and systematically ventilated, the external air being freely admitted when the weather will allow, and particular currents being established, by which floating particles are carried away in certain invariable and known courses. Miners and others who work at furnaces in which lead is smelted, fused, or oxidated, should be protected by a strong draught through the furnaces. According to Mr. Braid, wherever furnaces of such a construction were built at Leadhills, the colic disappeared; while it continued to recur where the furnaces were of the old, low-chimneyed form. Manufacturers of litharge and red-lead used formerly to suffer much in consequence of the furnaces being so constructed as to compel them to inhale the fine dust of the oxides. In drawing the furnaces the hot material is raked out upon the floor, which is two or three feet below the aperture in the furnace; and the finer particles are therefore driven up and diffused through the apartment. But this obvious danger is now completely averted by a subsidiary chimney, which rises in front of the drawing aperture, and through which a strong current of air is attracted from the apartment, the hot material on the ground performing the part of a fire.

In white-lead manufactories a very important and simple improvement has been effected of late in some places by abandoning the practice of dry-grinding. In all manufactories of the kind, the ultimate pulverizing of the white lead has been long performed under water. But in general the preparatory process of rolling, by which the carbonate is separated from the sheets of lead on which it is formed, continues to be executed dry. This is a very dangerous operation, because the workmen must inhale a great deal of the fine dust of the carbonate. In a white-lead manufactory which formerly existed at Portobello, the process was entirely performed under water or with damping; and to this precaution in a great measure was imputed the improvement effected by the proprietor in the health of the workmen, and their superior immunity from disease over those of Hull and other places, where the same precaution was not taken at that time. The only operation latterly considered dangerous at the Portobello works was the emptying of the drying stove, and the packing of the white lead in barrels; and the dust diffused in that process was kept down as much as possible by the floor being maintained constantly damp. By these precautions, by making the workmen wash their hands and faces before leaving the works for their meals, and by administering a brisk dose of castor oil on the first appearance of any complaint of the stomach or bowels, the manufacturer succeeded in extirpating colica pictonum entirely for several years.—This trade continues to be a very pernicious one in France; for no fewer than 266 cases of colic were admitted into the Parisian hospitals in 1841 from the white-lead manufactories in and near the capital. Yet facts are not wanting there to prove that with proper care the disease may be all but extirpated. A French manufacturer, whose workmen at one time suffered severely, had no case of colic among them for nine years after breaking them in to the observance of due precautions.[^[1378]] Another says, from his own experience and information obtained at other works, he is satisfied the risk is very much greater among the intemperate than among sober workmen.[^[1379]]

CHAPTER XIX.
OF POISONING WITH BARYTA.

Baryta and its salts, the last genus of the metallic irritants which requires particular notice, are commonly arranged among earthy substances, but on account of their chemical and physiological properties, may be correctly considered in the present place. These poisons are worthy of notice, because they are not only energetic, but likewise easily procured, so that they may be more extensively used, when more generally known.

Section I.—Of the Chemical Tests for the preparations of Baryta.

Three compounds of this substance may be mentioned, the pure earth or oxide, the muriate, or chloride of barium, and the carbonate. The pure earth, however, is so little seen, that it is unnecessary to describe its chemical or physiological properties.

The Carbonate of Baryta is met with in two states. Sometimes it is native, and then commonly occurs in radiated crystalline masses, of different degrees of coarseness of fibre, nearly colourless, very heavy, and effervescing with diluted muriatic acid. It is also sold in the shops in the form of a fine powder of a white colour, prepared artificially by precipitating a soluble salt of baryta with an alkaline carbonate. It is best known by its colour, insolubility in water, solubility with effervescence in muriatic acid, and the properties of the resulting muriate of baryta.

The Muriate of Baryta, or chloride of barium, is the most common of the compounds of this earth, having been for some time used in medicine for scrofulous and other constitutional disorders. It is procured either by evaporating the solution of the carbonate in hydrochloric acid, or by decomposing a more common mineral, the sulphate, by means of charcoal aided by heat, dissolving in boiling water the sulphuret so formed, and decomposing this sulphuret by hydrochloric acid.

It is commonly met with in the shops irregularly crystallized in tables. It has an acrid, irritating taste, is permanent in the air, and dissolves in two parts and a half of temperate water.

The solution is distinguished from other substances by the following chemical characters. From all other metallic poisons hitherto mentioned, it is easily distinguished by means of hydrosulphuric acid, which does not cause any change in barytic solutions. From the alkaline and magnesian salts it is distinguished by the effects of the alkaline sulphates, which have no visible action except on the barytic solution, and cause in it a heavy white precipitate, insoluble in nitric acid. From the chlorides of calcium and strontium, it is to be distinguished by evaporating the solution till it crystallizes. The crystals are known not to be chloride of calcium, because they are not deliquescent. The chloride of strontium (which resembles that of barium in many properties, but which must be carefully distinguished, as it is not poisonous), differs in the form of the crystals, which are delicate six-sided prisms, while those of the barytic salt are four-sided tables, often truncated on two opposite angles, sometimes on all four,—by its solubility in alcohol, which does not take up the chloride of barium,—and by its effect on the flame of alcohol, which it colours rose-red, while the barytic salts colour it yellow. The chloride of barium is known from other soluble barytic salts, by the action of nitrate of silver, which throws down a white precipitate.

Vegetable and animal fluids do not decompose the solution of chloride of barium, except by reason of the sulphates and carbonates which most of them contain in small quantities. But the action of its tests may be distinguished, although the salt has not undergone decomposition. In that case the most convenient method of analysis is to add a little nitric acid, which will dissolve any carbonate of baryta that may have been formed,—to filter and then throw down the whole baryta in the form of sulphate, by means of the sulphate of soda,—and to collect the precipitate, and calcine it with charcoal for half an hour in a platinum spoon or earthen crucible, according to the quantity. A sulphuret of baryta will thus be procured, which is to be dissolved out by boiling water, and decomposed after filtration by muriatic acid. A pure solution is thus easily obtained. Orfila has lately proposed a process more complex in its details, but the same in principle.[^[1380]]

Section II.—Of the Action of the Salts of Baryta, and the Symptoms they excite in Man.

The action of the barytic salts on the body is energetic. Like most metallic poisons, they seem to possess a twofold action,—one local and irritating, the other remote and indicated by narcotic symptoms. This narcotic action is more decided and invariable than in the instance of any of the metallic poisons hitherto noticed. Such at least is the result of the experiments of Sir B. Brodie,[^[1381]] which have since been amply confirmed by Professor Orfila[^[1382]] and Professor Gmelin.[^[1383]] Orfila found that when the chloride was injected into the veins of a dog in the dose of five grains only, death ensued in six minutes, and was preceded by convulsions, at first partial, but afterwards affecting the whole body. Sir B. Brodie found the same effects follow in twenty minutes, when ten grains were applied to a wound in the back of a rabbit,—the convulsions being preceded by palsy, and ending in coma. Half an ounce when injected into the stomach excited the same symptoms in a cat, and proved fatal in sixty-five minutes, though the animal vomited. Schloepfer observed, that when a scruple, dissolved in two drachms of water, was injected into the windpipe of a rabbit, it fell down immediately, threw back its head, was convulsed in the fore-legs, and died in twelve minutes.[^[1384]] Gmelin observed in his experiments that it caused slight inflammation of the stomach, and strong symptoms of an action on the brain, spine, and voluntary muscles. He found the voluntary muscles destitute of contractility immediately after death; yet the heart continued to contract vigorously for some time, even without the application of any stimulus. From some experiments made on horses by Huzard and Biron, by order of the Société de Santé of Paris, it appears that the hydrochlorate, when given to these animals in the dose of two drachms daily, produced sudden death about the fifteenth day, without previous symptoms of any consequence.[^[1385]] In the experiments now related, very little appearance of inflammation was found in the parts to which the poison was directly applied. It is also worthy of remark that the heart does not seem to have been particularly affected; and yet according to the recent researches of Mr. Blake, the barytic salts are the most powerful of all inorganic poisons in their action on the heart, when they are injected into the veins. A quarter of a grain of the chloride appreciably depresses arterial action; two grains completely arrest the heart’s contractions in twelve seconds; and when it is injected back into the aorta from the axillary artery, it causes at first some obstruction to the capillary circulation, but soon arrests the action of the heart, as when it is introduced into the veins.[^[1386]]

The pure earth appears to produce nearly the same effects in an inferior dose. When swallowed, the symptoms of local irritation are more violent; but death ensues in a very short space of time, and is preceded by convulsions and insensibility. The stomach after death is found of a reddish-black colour, and frequently with spots of extravasated blood in its villous coat.

The carbonate in a state of minute division is scarcely less active than the hydrochlorate, since it is dissolved by the acid juices of the stomach. A drachm killed a dog in six hours; vomiting, expressions of pain, and an approach to insensibility preceded death; and marks of inflammation were found in the stomach.[^[1387]] Pelletier made many experiments on the poisonous properties of the carbonate. Fifteen grains of the native carbonate killed one dog in eight hours, and another in fifteen.[^[1388]] Dr. Campbell found it to be a dangerous poison, even when applied externally. Twelve grains introduced into a wound in the neck of a cat, excited on the third day languor, slow respiration, and feeble pulse; towards evening the animal became affected with convulsions of the hind-legs and with dilated pupils; and death followed not long afterwards.[^[1389]] This substance, before its real nature was known, used at one time to be employed in some parts of England as a variety of arsenic for poisoning rats.

The salts of baryta are absorbed in the course of their action. The chloride has been detected by Dr. Kramer both in the blood and urine by incineration with carbonate of potash, washing the ashes with weak solution of carbonate of potash, dissolving the residue in diluted nitric acid, and testing the solution for baryta.[^[1390]] Orfila has also obtained baryta, by his process alluded to above, in the liver, kidneys, and spleen of animals killed by the chloride.[^[1391]]

The symptoms produced by the salts of baryta in man have seldom been particularly described. An instance is shortly noticed in the Journal of Science, where an ounce of the hydrochlorate was taken by mistake for Glauber’s salt, and proved fatal. The patient immediately after swallowing it felt a sense of burning in the stomach; vomiting, convulsions, headache, and deafness ensued; and death took place within an hour.[^[1392]] A similar case, fatal in two hours, has been related by Dr. Wach of Merseburg. A middle-aged woman who, though generally in good health, had suffered for a day or two from pains in the stomach, took one morning a solution of half an ounce of chloride of barium by mistake for sulphate of soda. She was soon seized with sickness, retching, convulsive twitches of the hands and feet, vomiting of clear mucus, great anxiety, restlessness, and loss of voice; and she died under constant efforts to vomit, and violent convulsive movements, but with her faculties entire.[^[1393]]

Unpleasant effects have been observed from too large doses of the chloride administered medicinally. A case is mentioned in the Medical Commentaries of a gentleman who was directed to take a solution as a stomachic, but swallowed one evening by accident so much as seventy or eighty drops. He had soon after profuse purging without tormina, then vomiting, and half an hour after swallowing the salt excessive muscular debility, amounting to absolute paraplegia of the limbs. This state lasted about twenty-four hours, and then gradually went off.[^[1394]] I have known violent vomiting, gripes, and diarrhœa produced in like manner by a quantity not much exceeding the usual medicinal doses.

Dr. Wilson of London has lately described a distinct case of poisoning with the carbonate. The quantity taken was half a tea-cupful; but emetics were given, and operated before any symptoms showed themselves. In two hours the patient complained of dimness of sight, double vision, headache, tinnitus, and a sense of distension in the stomach, and subsequently of pains in the knees and cramps of the legs, with occasional vomiting and purging next day; for some days afterwards the head symptoms continued, though more mildly, and she was much subject to severe palpitations; but she was in the way of recovery when the account of her case was published.[^[1395]] Mr. Parkes mentions that, according to information communicated to him by the proprietor of an estate in Lancashire, where carbonate of baryta abounds, many domestic animals on his estate died in consequence of licking the dust of the carbonate, and that it once proved fatal to two persons, a woman and her child, who took each about a drachm.[^[1396]] Dr. Johnstone says he once swallowed ten grains of this compound, without experiencing any bad effect.[^[1397]]

Section III.—Of the Morbid Appearances caused by the Salts of Baryta.

In animals the mucous membrane of the stomach is usually found of a deep-red colour, unless death take place with great rapidity, in which case the alimentary canal is healthy. In all the animals, which in Dr. Campbell’s experiments were killed by the application of the muriate to wounds, the brain and its membranes were much injected with blood; and in one of them the appearances were precisely those of congestive apoplexy.

In Wach’s case the stomach was dark brownish-red externally, and the small intestines brighter red. Internally the stomach presented uniform deep redness, with clots of blood, and bloody mucus scattered over it; and near the cardiac end there was a perforation, above half an inch in diameter within, and half as wide at the outside, and surrounded with swollen edges and extensive thickening of the villous coat. The small intestines were internally very red and lined with red mucus interspersed with clots of blood. The great intestines were extremely contracted. The lungs were gorged, the heart full of dark liquid blood, and the cerebral vessels distended. Chloride of barium was detected in the stomach and intestines. The perforation in this case was evidently an accidental concurrence.

Section IV.—Of the Treatment.

The treatment of this variety of poisoning consists chiefly in the speedy administration of some alkaline or earthy sulphate, such as the sulphate of soda or sulphate of magnesia. The poison is thus immediately converted into the insoluble sulphate of baryta, which is quite inert. Two drachms of muriate of baryta were injected by Orfila into the stomach of a dog, and eight minutes afterwards two drachms of sulphate of soda. The gullet was then secured by a ligature. At first efforts were made to vomit, and in an hour sulphate of baryta was discharged with the alvine evacuations. There was neither insensibility nor convulsions; and the next morning the animal evidently suffered only from the ligature on the gullet. This fact not only proves the efficacy of the sulphate, but likewise shows that in the kinds of poisoning where diarrhœa occurs, the poison is very soon discharged, and ought therefore to be looked for in the evacuations from the bowels.[^[1398]]

A few observations may be here added on the effects of the salts of strontia on the animal frame. These compounds bear a close resemblance to the salts of baryta, and the two earths were consequently long confounded together till Dr. Hope pointed out their distinctions. One of the most striking differences is, that the salts of the strontia are very feebly poisonous. Some experiments of this purport were made by M. Pelletier of Paris,[^[1399]] and by Blumenbach; but the most accurate researches are those of Professor Gmelin. He found that ten grains of the chloride in solution had no effect when injected into the jugular vein of a dog,—that two drachms had no effect when introduced into the stomach of a rabbit,—that half an ounce was required to cause death in that way,—that two drachms of the carbonate had no effect,—and that two drachms of the nitrate, dissolved in six parts of water and given to a rabbit, merely caused increase of the frequency and hardness of the pulse and a brisk diarrhœa.[^[1400]] Mr. Blake also found that small doses of the salts of strontia have little effect when injected into the veins; but that forty grains arrest the action of the heart in fifteen seconds.[^[1401]]