Cl. IV. NARCOTIC POISONS.
These constitute a class of vegetable poisons, less extensive, perhaps, but of far greater importance and interest, than the one we have already considered. It would not be easy to enumerate the various purposes to which the active imagination of man has applied the tribe of narcotic plants. Medicines, poisons, intoxication, and madness, lie concealed beneath their juices. They have, in their turn, arrested the pangs of disease, and inflicted death upon the unsuspecting object of hatred and revenge; they have animated the courage of the warrior, inspired the enthusiasm of the poet, soothed the sorrows of the wretched, and furnished the debauchee with a daily source of sensual gratification; effects which, although apparently incompatible with each other, may be commanded by the same substance, in a different dose. It would be foreign to the plan of this work to enter into a physiological inquiry into the modus operandi of these extraordinary agents; and the author relinquishes the labour with less regret, as he has already, in another work,[[415]] very fully considered the several theories which have been advanced for its explanation.
Opium, and its Preparations.
This well known drug is the inspissated juice of the Papaver Somniferum (Polyandria Monogynia. Nat. Ord. Rhoedææ, Linn. Papaveraceæ Juss.) obtained by making incisions in the half ripe capsules, at sun-set, when the night dews favour the exudation of the juice, which is collected in the morning by old women and children, who scrape it from off the wounds with a small iron scoop, and deposit the whole in an earthen pot, where it is worked by wooden spatulas in the sun-shine, until it attain a considerable degree of spissitude. It is then formed by the hand into cakes, which are laid in earthen basins to be further exsiccated.[[416]] Two kinds are found in commerce, distinguished by the names of Turkey, and East Indian opium. The latter kind is regarded as being inferior to the former.
Turkey opium occurs in flat pieces, of a solid compact texture, possessing considerable tenacity; its specific gravity is 1·336, so that, when compared with concrete juices of other plants, it is heavy, being exceeded only in this respect by opoponax and gum arabic. It is of a reddish-brown, or fawn-colour, and has a peculiar, heavy, and narcotic odour; its taste is acrid, bitter, and hot. By long exposure to the air, it becomes hard, and breaks with a glimmering fracture, owing to the presence of a few saline particles. It is plastic, and when worked with the fingers is adherent to them. When brought near a lighted candle it inflames, and burns with a brilliant light, but its odour at that time is not narcotic. It is partially soluble in water, alcohol, æther, wine, vinegar, and lemon-juice. When triturated with hot water, five parts in twelve are dissolved, six suspended, and one part remains perfectly insoluble, and resembles the gluten of wheat, but is of a dark colour. The alcoholic is more highly charged with its narcotic principle than the aqueous solution; but spirit, rather below proof, is its best menstruum.
Few vegetable substances have been more frequently, or more ably submitted to analysis; and the history of the successive steps by which our knowledge respecting its composition has advanced, must encourage us in hoping that we shall shortly be enabled to identify, by chemical tests, the presence of opium, with as little difficulty and as great precision as we are already capable of recognising a metallic poison.
According to the latest chemical views respecting the composition of this body, it may be stated to consist of the following principles, viz. resin, gum, bitter extractive, sulphate of lime, gluten, and the three lately discovered bodies, narcotine, morphia, and meconic acid.
In the year 1803, Derosne first obtained from opium a crystalline substance, which he found to dissolve in acids, but he does not appear to have instituted many experiments, for the elucidation of its nature and properties. In 1804 Seguin discovered another crystalline body, and although he described many of its properties, what appears very extraordinary, he never even hinted at its alkaline nature. Sertuerner, at Eimbeck in Hanover, had at the same time as Derosne and Seguin, obtained these crystalline bodies, but it was not until the year 1817, that he first proclaimed the existence of a vegetable alkali, and attributed to it the narcotic powers which distinguish the operation of opium; to this body, he gave the name of Morphia, and it would appear to be the same as the essential salt of Seguin. The salt of Derosne was also at first mistaken for the same principle, but the experiments of Robiquet have pointed out its distinctive properties, and it has received the name of Narcotine.
Morphia, upon which the soporific powers of opium depend, appears to exist in native combination with a peculiar acid, to which the name of meconic acid has been bestowed. The following are the essential characters of this alkaline body, when procured in a state of purity.[[417]]
It crystallizes in fine, transparent, truncated pyramids, the bases of which are either squares or rectangles, occasionally united base to base, and thereby forming octohedra. It is sparingly soluble in boiling water, but dissolves abundantly in heated alcohol, giving rise to an intensely bitter solution; in æther it is far less soluble. It has also the characters of an alkali; affecting test papers tinged with tumeric or violets, uniting with acids and forming neutral salts, and decomposing the compounds of acids with metallic oxides. It unites with sulphur by means of heat, but the combination is no sooner formed than it is decomposed. It fuses at a moderate temperature, when it resembles melted sulphur, and like that substance crystallizes on cooling; it is decomposed by distillation, yielding carbonate of ammonia, oil, and a black resinous residue, with a peculiar smell; when heated in contact with air, it inflames rapidly, and like vegetable matter, it leaves a carbonaceous residue. When analyzed by means of the deutoxide of copper, it yields carbon, hydrogen, and oxygen, the atomic proportions of which have not yet been ascertained. The nitric acid of commerce, when dropped on morphia, communicates to it a beautiful red colour. Sertuerner has given us an account of the effect of the alcoholic solution of morphia on himself, and three of his pupils; he found that repeated small doses of half a grain produced at first decided excitation; then weakness, numbness, and tendency to fainting; after swallowing vinegar while in this condition, violent vomiting was excited; in one delicate individual, profound sleep intervened, and on the following day he suffered from nausea, vomiting, head-ache, anorexia, constipation, and heaviness.[[418]] This case is sufficient to shew, that although morphia possesses the characteristic powers of opium, its strength is by no means commensurate with its supposed state of concentration. When uncombined, it exerts little or no action, in consequence of its insolubility in water, and in the fluids of the stomach. When, however, it is combined with an acid, particularly the acetic, or the meconic, with the latter of which we have before stated that it exists in opium, it displays its properties in a very eminent degree. It is also very soluble in oil; and, according to the experiments of M. Majendie, the compound acts with great intensity.
The meconic acid, when separated from the residuum of the magnesian salt, as described in the process for the preparation of morphia (note p. [386]) does not appear to possess any medicinal activity. Its distinguishing chemical character is, that it produces an intensely red colour in solutions of iron, oxidized ad maximum; and a deep blue, with solutions of the salts of gold. Narcotine is the salt originally obtained by Derosne, and is supposed by MM. Majendie and Robiquet to be the peculiar principle which produces the excitement experienced by those who take small doses of opium. It may be entirely removed by macerating the extract of opium in sulphuric æther.
Symptoms of poisoning by Opium.
In considerable doses, the primary action of this substance, as a powerful and diffusible stimulant, is not apparent; for the powers of life are immediately depressed, drowsiness and stupor succeed, and these are followed by delirium, stertorous breathing, cold sweats, convulsions, and apoplectic death.
The quantity of opium necessary for the production of such effects must be regarded as relative. In no two cases can we ensure a similar result, by the administration of the same dose. But, of all the circumstances capable of modifying the power of this drug, habit is the most remarkable; in illustration of which we have only to adduce the history of the opium eater, or laudanum drinker; a species of debauchee by no means uncommon, as every London chemist can testify, for he frequently experiences considerable doubt and difficulty in distinguishing persons, to whom habit has rendered large doses of opium necessary, from such as purchase it with a view to suicide.[[419]] The lowest fatal dose, to those unaccustomed to it, seems to be about four grains; but the Turk will take three drachms in the morning, and repeat the same dose at night, without any other effects than that of cheerfulness and exhilaration. This temporary impunity, however, is dearly purchased by years of suffering and sorrow. The effects of opium, says Russel, on those who have been addicted to it, are at first obstinate costiveness, succeeded by diarrhœa and flatulence, with loss of appetite, and a sottish appearance; their memories soon fail, they become prematurely old, and then sink into the grave objects of scorn and pity.[[420]]
Where a person has, from accident, or design, swallowed a large dose of pure opium, or laudanum, the symptoms produced are so characteristic and striking, that the practitioner, who may be summoned to render assistance, will have no difficulty in ascertaining their cause.
Insensibility, with a scarcely perceptible respiration, although in some cases it is attended with an apopletic stertor; the countenance is livid and cadaverous; the skin cold; and the muscles of the limbs and trunk in a state of extreme relaxation. The pupils are insensible to the impression of light, and the pulse is almost imperceptible. In some stages, the patient, by being strongly shaken, may be roused for a few moments from the lethargy; there is generally a narcotic odour distinguishable in the breath. Vomiting may also take place upon the first impression of the laudanum upon the stomach; although after its action has been displayed upon the brain, it will be difficult to excite emesis by the most powerful means; the reason of which may be very satisfactorily deduced from the ingenious experiments of M. Majendie on the mechanism of vomiting; by which he proves, that without the influence of the brain, the muscles, whose actions constitute an essential part of the operation, are incapable of performing their duty, and that vomiting therefore cannot take place. This is a very important doctrine, inasmuch as it suggests to the pathologist several expedients, by which he may be enabled to occasion vomiting, by recalling the excitability of the brain. The period which will elapse, between the ingestion of the poison, and the death of the sufferer, may be stated to be from six to twenty-four hours; but it will in each case be liable to vary, not only from the quantity of opium swallowed, but from the habit and peculiar circumstances of the individual submitted to its operation.
Physiological action of Opium.
It is still a question for the decision of future physiologists, whether the narcotic principle of opium destroys the functions of the nervous system by a local impression upon the stomach,[[421]] or by being absorbed,[[422]] and brought into contact with the brain in the course of the circulation. We are inclined to adopt this latter opinion, and have therefore placed opium in the second division of our classification; at the same time, we think that it may occasionally produce an effect upon the nervous extremities of the stomach, and we have accordingly placed an asterisk against the word, by which we denote this double mode of operation. But, by whatever medium it may act, it is evident that it occasions death by destroying the functions of the brain; in consequence of which the muscles of respiration, no longer supplied with nervous energy, cease to contract, and the animal dies in a state of suffocation.[[423]]
Of the treatment in cases of poisoning by Opium.
The first object is the evacuation of the stomach by vomiting; for which purpose, the patient should be made to swallow from fifteen grains to a scruple of sulphate of zinc; or, from five to ten grains of sulphate of copper dissolved in water; and the vomiting should be kept up for a considerable time, and urged by irritation of the fauces. Where the act of vomiting cannot be established, in consequence of the paralysed state of the nervous system, cold affusion, applied by means of a shower bath, has been said to restore the energy of the brain, and thus to render the patient susceptible of the stimulus of an emetic.[[424]] Venesection has also, under the same circumstances, been greatly extolled; and, as vascular congestion in the brain is one of the effects of this poison, it is reasonable to conclude that, by unloading the vessels of this organ, we may restore its lost sensibility. Tissot has strongly recommended the practice,[[425]] and the experiments of Orfila have shewn that it never aggravated the symptoms of poisoning by opium, nor accelerated the moment of death; but on the contrary, that in some instances he found that it restored the animals which would have died, if it had not been put in practice. Where the operation is performed, the blood should be drawn from the jugular vein, in preference to any other. Should these means prove insufficient to provoke vomiting, M. Orfila asks, whether one or two grains of tartarized antimony, dissolved in one or two ounces of water, might not be injected into the veins? It was formerly proposed by Boerhaave to empty the stomach of its poisonous contents, by the introduction of a syringe; an operation which, it is said, has been lately performed with success.[[426]] Vinegar and vegetable acids were long considered as antidotes to opium; but the experiments of M. Orfila have clearly established that, as long as any portion of the opium remains in the stomach, these potations, so far from relieving, aggravate the symptoms of poisoning by this narcotic, in consequence of the power which they possess of dissolving it. Where, however, the opium has been expelled by vomiting, these acid drinks possess the property of diminishing the consecutive symptoms, and of thus realising the expectations which Virgil[[427]] has so poetically raised,
----“quo non præsentius ullum
Auxilium venit, ac membris agit atra venena.”
The powers of the habit should, at the same time, be supported by brandy, strong coffee, and cordials. The sufferer should be kept awake; and, if possible, in a continued gentle motion. Dr. Currie[[428]] has recommended the affusion of warm water at 106°, or 108°, for removing the stupor.
A case is recorded by Dr. Marcet, in the first volume of the Medico-chirurgical Transactions, where six ounces of laudanum were taken by a young man, and remained for five hours in the stomach before any remedies were applied for its removal; a strong dose of sulphate of copper, however, provoked vomiting, and by judicious treatment he eventually recovered.
Organic lesions discovered on dissection.
It has been very truly remarked that although the instances in which opium has proved fatal to human life have been very numerous, yet that the accounts which we have received of the appearances of the body post mortem, are by no means so satisfactory as we could desire. M. Orfila asserts that no alteration can be discovered on dissection, in the digestive canal of persons who have swallowed any narcotic poison; and that if facts contrary to this assertion be met with in various authors, it is because there have been administered irritating substances capable of producing inflammation.[[429]] The lungs, however, frequently exhibit morbid phenomena; their colour is sometimes violet, and frequently a deeper red than in the natural state. Their texture is also more dense, and less crepitating; and they are marked by livid spots. The blood contained in the ventricles of the heart, and in the veins, is said to be found in a liquid state; but Orfila advances a diametrically opposite opinion, and asserts that it is frequently coagulated. The brain and its membranes often exhibit a state of vascular congestion; in the case recorded by Mr. Stanley, in the sixth volume of the Transactions of the College of Physicians, the cellular tissue of the pia mater was found to contain water.[[430]]
Of the detection of Opium.
There is no mode of identifying opium, whether in a liquid or solid form, so satisfactory as that which is at once afforded by its powerful and highly characteristic odour. In fatal instances, we shall always meet with it in the contents of the alimentary canal, and in such quantities as will leave no doubt as to its nature. The chemist may also proceed to a farther examination, by obtaining morphia from its solution, by a process which we have already described under the chemical history of opium.
Black Henbane. Hyoscyamus Niger.
(Pentandria Monogynia. Nat. Ord. Luridæ Linn. Solaneæ Juss.)
Henbane is an indigenous annual, frequent on waste grounds, and at the sides of roads, particularly on a calcareous soil, flowering in July. The whole of the plant is poisonous when eaten; and in the recent state the odour of the leaves occasions stupor and delirium. The root of this plant when in full vegetation is very powerful; and there are several cases on record, where it has been eaten in mistake for parsnips,[[431]] which it strongly resembles in its sweet and agreeable flavour. Its operation is very analogous to that of opium; producing sickness, stupor, delirium, and coma, with dilation of the pupils.
The pulse, at first hard, gradually becomes weak and tremulous; petechiæ frequently make their appearance, and death ensues. Late experiments have shewn that a peculiar alkaline body constitutes the active principle of this plant, and it has accordingly received, from its discoverers MM. Meissner and Brandes, the name of Hyoscyama.
Boerhaave experienced a trembling and drunkenness, in consequence of having prepared a plaister, into whose composition henbane entered as an ingredient; and the experiments of M. Orfila have shewn that it acts nearly in the same manner, whether applied upon the cellular texture, introduced into the stomach, or injected into the veins. Hence it follows that the active principle of this plant is carried into the circulation, and exerts a remarkable action on the brain and nervous system, producing an extraordinary state of delirium, which is succeeded by stupefaction. The physician will never probably be called upon to investigate a case of wilful poisoning by this narcotic; and should he be summoned to attend a person who, through mistake or accident, had swallowed it, we can hardly anticipate any peculiar mystery which requires elucidation.
There are several other species of henbane, as hyos. alb. aureus, physaloides, all of which are poisonous, although not in the same degree as the hyoscyamus niger, whose history we have just considered.
Prussic Acid. Hydro-cyanic Acid.
The Laurel (Prunus lauro-cerasus) and its distilled water. Bitter Almonds, and their essential oil.
Hydro-cyanic acid exists in a great variety of native combinations in the vegetable kingdom, and imparts to them peculiar qualities, which have been long known. It is, however, only within a few years, that this singular body has been obtained in its separate and independent form[[432]]; indeed it was not until the publication of the celebrated memoir of Gay-Lussac upon this subject, in the year 1815, that its chemical composition was fully understood. In this memoir, it was clearly shewn to consist of a peculiar, gaseous, and highly inflammable compound of carbon and nitrogen, to which the name of cyanogene has been assigned, and hydrogen; the latter body acting as the acidifying principle; whence the term hydro-cyanic acid is very happily contrived to express its composition.
When obtained in its most concentrated form, by the process of M. Gay Lussac,[[433]] it has the following characteristic properties, viz. At ordinary temperatures, it is liquid, colourless, and transparent; possessing an extremely powerful odour, very analogous to that of the blossom of the peach, or bitter almond tree; its taste is, at first, bland and sweetish, but afterwards pungent, bitter, and peculiar. Its extreme volatility is such, that when a drop of it is exposed to the air, on the end of a glass rod, it is rapidly crystallized. The same phenomenon takes place, if a drop be suffered to fall on a sheet of paper. Its specific gravity is ·7055; but, when in a concrete form it is only ·9, while that of its vapour is ·947. If inhaled, it produces almost immediate pain in the head, with deafness, unless very largely diluted with air or water.[[434]] It is decomposed by a high temperature; and by the action even of light it is, in the course of a very short time, resolved into carbonic acid, ammonia, and carburetted hydrogen, a carbonaceous matter remaining behind.[[435]] When brought near a body in a state of combustion, it instantly inflames and burns with a blue light. In water it is sparingly soluble; alcohol dissolves it copiously.
The “medicinal Prussic acid,” as it has been called, as being the preparation lately introduced into medicine,[[436]] differs only from that we have just described, in its degree of concentration. It is, in fact, the Prussic acid of Scheele, and may be considered as equivalent to the preparation of Gay-Lussac diluted with six times its volume, or eight times and a half its weight, of distilled water.
The hydro-cyanic acid has been discovered, in a state of perfect formation, in a variety of vegetables, whose peculiar odour at once announces its presence; such are bitter almonds; the kernels of apricots, cherries, particularly the Cerasa Juliana, and several plums; the leaves of laurel; and peach blossoms; and the bark of the prunus padus, or bird-cherry tree. The only mineral substance, in which hydro-cyanic has yet been detected is the Fer Azuré of Hauy.[[437]] Animal substances, although they do not contain it ready formed, yet, when treated with an alkali at a high temperature, they yield it in great abundance, in consequence of the combination of its elements.
Action of hydro-cyanic Acid as a Poison.
The experiments which have been instituted with a view to ascertain the exact effects of this substance upon animal life, very clearly prove that the acid of Gay-Lussac is one of the most active poisons in nature; and that the various vegetable bodies, into whose composition it enters, exert an energy, corresponding with the quantity of this constituent, and the degree of concentration, in which it exists. The experiments of M. Orfila were made with Prussic acid, prepared according to the process of Scheele, and consequently containing a great proportion of water, as we have already explained; and yet the effects which followed its administration were extremely energetic. From the Annales de Chimie, for October 1814, we learn that a professor of chemistry, having inadvertently left on his table a phial filled with a solution of Prussic acid in alcohol, a female servant, who had been seduced by its agreeable smell, drank a small glass-full of it, and fell dead at the end of a few minutes, as if struck by apoplexy.
The following case is quoted by Dr. Granville, from Hufeland. D. L. a robust and healthy man, aged 36 years, while about to be seized as a thief by the police officers, snatched a small sealed phial from his pocket, broke off the neck of it, and swallowed the greatest part of its contents. A strong smell of bitter almonds soon spread around, which almost stupefied all present. The culprit staggered a few steps; then, without a groan, fell on his knees, and sunk lifeless down to the ground. Medical assistance being called in, not the slightest trace of pulse or breathing could be found. A few minutes afterwards, a single and violent expiration occurred, which was again repeated in about two minutes. The extremities were perfectly cold, the breast and abdomen still warm, the eyes half open and shining, clear, lively, full, almost projecting, and as brilliant as those of the most ardent youth under violent emotion. The face was neither distorted nor convulsed, but bore the image of quiet sleep. The corpse exaled a strong smell of bitter almonds, and the remaining liquid, being analysed, was found to be a concentrated solution of Prussic acid in alcohol. Cases also stand recorded where, from imprudent exposure to the vapours of the Prussic acid, persons have exhibited all the appearances of being poisoned. Some writers assert that Scheele himself, who died suddenly, while engaged in some inquiries into the nature and formation of this acid, was affected by its deleterious qualities. Orfila relates that Scharinger, Professor at Vienna, prepared some pure concentrated Prussic acid, and having diffused a certain quantity of it upon his naked arm, he died a short time afterwards. The professor, however, did not die in consequence of this accident; it appears, upon inquiry, that he was seized with apoplexy while sitting in a coffee house in the evening.
The distilled water of the cherry laurel[[438]] has been proved, by numerous awful examples, to be a most energetic poison; and from the fatal effects to which the officinal preparation of it gave rise, it was early expunged from the Pharmacopœia of the London College. In the Philosophical Transactions for the year 1731, we shall find the history of its effects upon a woman of the name of Boyce, who, with a view to disprove an allegation, that one Mary Whaley had died in consequence of drinking a small quantity of laurel water, swallowed three spoonsful, and, afterwards, two more of the same liquid; after which she died in a very short time, without making the least complaint, and without any convulsion.
Foderé informs us that during the period he was pursuing his studies at Turin in 1784, the chambermaid and man servant of a noble family of that town, for the purpose of regaling themselves, stole from their master a bottle of distilled laurel water; fearful of being surprised, they hastily swallowed several mouthsful of it; but they soon paid the price of their dishonesty, having almost instantly expired in convulsions. Works on Toxicology also abound with the relation of experiments, made by numerous physiologists on different animals, with this deleterious liquid. Amongst the experimentalists we may enumerate the names of Madden, Mortimer, Browne, Langrish, Nicholls, Stenzelius, Heberden, Watson, Vater, Rattrai, the Abbé Rozier, Duhamel, Fontana, and Orfila. In this country we have had several fatal cases of poisoning by laurel water. In the year 1782, Dr. Price, of Guildford, having professed to have converted mercury into gold, offered to repeat his experiments before a competent tribunal, but the unfortunate philosopher put a period to his existence before the day appointed for his exhibition, by a draught of laurel water; a mode of death which had been, no doubt, suggested by the celebrated trial of Donellan, for the murder of Sir Theodosius Boughton, that had taken place in the preceding year, and left a strong impression upon the public mind; and whose details, it has been justly observed, are not more important from the elucidation of the effects of this poison, than from the strange display of professional testimony to which it gave origin, (see Appendix, page 243.) There are those who still profess to believe that the prisoner was unjustly convicted upon that occasion; Dr. Male states, without the least reserve, that it was neither proved that the deceased was poisoned, nor that any poison had existed.[[439]] We feel no difficulty in declaring that we hold a directly opposite opinion; and we consider that many of the weaker points of professional evidence delivered on the trial, have received powerful support and elucidation from the experiments and observations of later physicians.
Nor are the leaves of this plant wholly free from danger; it is true that they have, for many years, been in general use among cooks, to communicate an almond or kernel-like flavour to custards, puddings, creams, blanc-mange, and other delicacies of the table; but the custom has not always been harmless; a fact with which it behoves the forensic physician to be acquainted. In some parts of the continent milk is boiled with one or two leaves of the cherry-laurel in it, and Ingenhouz states that he saw people much affected by it. In the Literary Chronicle (no. xxii, p. 348, 1819) we find the following illustrative case: “Several children at a boarding-school, in the vicinity of Richmond, having partaken of some custard flavoured with the leaves of the cherry-laurel, four of them were taken severely ill in consequence. Two of them, a girl of six, and a boy of five years of age, fell into a profound sleep, out of which they could not be roused for ten hours, the other two complained of severe pains in the epigastric region. By proper medical treatment, they all recovered, after an illness of three days.”
The essential oil of bitter almonds is equally poisonous; and the water distilled from them is highly dangerous if incautiously taken. Duvignau and Parent instituted some experiments upon themselves to ascertain this fact; they commenced by taking six drops of the water distilled three times, in an appropriate vehicle, without producing any other than a transient impression. On taking eighteen drops, however, vertigo was experienced, and a disposition to sleep, accompanied with a tingling of the ears and dimness of sight. When the dose was increased to twenty-two drops, alarming symptoms followed, such as convulsions, and vomiting; which, although the experimenters succeeded in allaying by antispasmodics, cured them completely of any ulterior wish to ascertain how far this substance might be deleterious. A drachm of the distilled water of bitter almonds has killed a moderate sized dog. The essential oil is proportionally more active; Mr. Brodie[[440]] found that one drop, when applied to the tongue of a cat, killed it in five minutes; no sooner did the poison come in contact with the organ than the animal was seized with convulsions. When two drops of the same oil were injected with half an ounce of water into the rectum of a cat, it was not seized for two minutes, but it died, as in the former experiment, after the expiration of five minutes. While engaged in this inquiry, Mr. Brodie dipped the blunt end of a probe into the essential oil, and applied it to his tongue, with the intention of tasting it, and not having the least suspicion that so small a quantity could produce any of its specific effects on the nervous system; but scarcely had he applied it, when he experienced a very remarkable and unpleasant sensation, which he referred chiefly to the epigastric region, but the exact nature of which he could not describe, because he knew nothing similar to it. At the same time there was a sense of weakness in his limbs, as if he had not the command of his muscles; and he thought that he should have fallen. The fascinating liqueur noyau, créme de noyau, is indebted for its flavour to the essential oil of the bitter almond, or peach; and is undoubtedly deleterious if taken in excess. In the Journal des Debats, for 1814, we find that the late Duke Charles de Lorraine had nearly lost his life from swallowing some drops of eau de noyau too strongly impregnated with the essential oil of peach kernels.
The bitter almond itself, in consequence of the manner in which its deleterious principle is modified by the natural state of combination in which it exists with sweet oil and albumen, does not produce an effect corresponding with the proportion of essential oil which it yields. The experiments of Orfila, however, prove that the almond, in doses of a drachm, is destructive to cats; and there can be no doubt but that it would be equally deleterious to the human species; but the quantity required for the production of such an effect must ever prevent the bitter almond from becoming either the accidental or criminal instrument of death.
Physiological action of Prussic acid.
The numerous experiments, which have been made with this poison, have clearly established that its action is upon the nervous system, whose energies it would seem to extinguish without any ostensible injury to respiration and circulation; for in all those animals which were killed by it, in the experiments of Orfila, Brodie, and others, the heart was found acting regularly, and circulating dark coloured blood, and in some cases this phenomenon was visible for many minutes after the animal was in other respects apparently dead. Orfila considers that he has fully demonstrated that these effects depend on the absorption of the poison, and its transmission to the brain through the medium of the circulation. We have accordingly placed Prussic acid in the second division of our classification. The essential oil of bitter almonds would, according to the experiments of Mr. Brodie, appear to act through the medium of the nerves, and it has accordingly been referred to our first division. This is undoubtedly an anomaly, which it is not easy to reconcile; the experiments, however, which led Mr. Brodie to the conclusion appear to us to warrant such a deduction; the instantaneousness with which the poisonous effects were produced, and the fact of its acting more speedily when applied to the tongue, than when injected into the intestines, although the latter presents a better absorbing surface, seem to oppose the idea of the oil requiring to be absorbed, before it can display its energies. M. Vogel, of Munich, has lately discovered some facts respecting the composition of this oil, which may perhaps hereafter lead to the true explanation of this apparent anomaly; this distinguished chemist succeeded in separating the Prussic acid from the volatile oil with which it is combined, by agitating the whole in a concentrated solution of potass, and distilling to dryness; the oil volatilized together with the water, while the residuum in the retort was found to contain cyanide of potassium. The oil, thus separated from the Prussic acid, is without odour, and heavier than water; its taste is extremely acrid and burning; in order to discover whether it was still poisonous, M. Vogel put a drop of it on the tongue of a sparrow, when it died in a few seconds, after a very violent convulsion; he also poisoned a dog, two months old, with four drops of it; whence he concludes that the volatile oil, divested of its hydro-cyanic acid is still a poison, although less energetic than that which has not undergone such a change. Do there exist then two independent principles of activity in the bitter almond? If such a fact were established it would not be solitary, for we shall hereafter shew that the energies of tobacco are dependant upon an analogous arrangement; and that our ignorance of the fact, at first, occasioned apparent anomalies, as embarrassing as those which at present involve the physiological history of the oil of almonds.
Antidotes.
Orfila, in his celebrated Toxicology, informs us that vinegar, or the vegetable acids; coffee; a solution of chlorine in water; camphor; emollient drinks; and bleeding, have been successively, but not successfully recommended.[[441]] With respect to the first of these pretended antidotes, it deserves notice, that instead of palliating the symptoms, it actually quickens, and gives more energy to the action of the poison. Coffee, as far as it may stimulate, might be employed with advantage; but its powers are not sufficient to meet the exigency of the case. Bleeding seems decidedly a fatal measure. The authors of the paper on Prussic acid, inserted in the American Recorder, consider at length the claims of every substance which has been proposed as an antidote to it; and they conclude by saying that, we are entirely ignorant of a counter-agent of this poison. There is every reason, says Dr. Granville, to believe that the Prussic acid taken in large quantities, and in its concentrated state, is partially, if not wholly absorbed ere it reaches the stomach;—else how happens it that scarcely a minute after its exhibition, I have, in common with others, been unable to detect its presence within that organ. If so, then all chemical attempts must be nugatory, no decomposition, or fresh combinations can be produced to render it harmless; nor will an emetic, although so much recommended, be of much more service in freeing the system of its presence. But although chemical remedies are thus shewn to be of no avail, we may derive from the class of vital agents some powerful antidotes; all medicines taken from the class of diffusible stimuli will be useful in supporting the powers of the system against the sedative influence of the poison. Hot brandy and water, with ammonia, camphor, and other similar stimulants, are the resources to which we should fly upon such occasions.
Organic lesions discovered on Dissection.
The recorded dissections of persons, who have been poisoned by Prussic acid, are too few and vague to furnish any satisfactory generalization. In the case related by M. Foderé, of two servants who died after a draught of laurel-water, the dead bodies were carried to the University at Turin, and examined, when the stomach was found slightly inflamed, but the other parts were in a sound state. We feel much hesitation in giving credit to this report, the death was too immediate to allow the access of inflammation; we are rather disposed to consider the appearances of the stomach to have arisen from that species of sanguineous congestion, which we have before alluded to, as sometimes occurring in cases of sudden death. In other cases the coats of the stomach are said to have been black and relaxed; the vessels of the brain injected; the lungs have also been described as presenting unnatural congestions, and purple spots; and the smell of Prussic acid seemed as if it pervaded the whole system, and was embodied, as it were, with the very substance of the muscles. In other cases, again, not the slightest trace of any morbid appearance could be discovered. Some authors have stated that in cases of death by this poison the cornea of the eye does not collapse, but retains its fulness, and even its lustre, for a considerable period.
Chemical processes by which the presence of hydro-cyanic acid may be ascertained.
The strong odour yielded by the body on dissection, will furnish a satisfactory proof of the presence of this poison. Instances may occur, when the practitioner will be called before a tribunal to answer, from his professional knowledge, whether a particular case of death can have happened from the action of the hydro-cyanic acid, or any of the compounds in which it may enter as an ingredient; it therefore becomes an object of great importance to inquire whether any farther tests might be made subservient to our purpose. Dr. Granville, who has directed a great share of his attention to the history of this poison, has given some directions upon this point, which appear to us to be useful and judicious; we shall, therefore, present them to our readers. “After collecting the blood contained in the ventricles of the heart, a portion of the contents of the stomach, and of the superior intestines, together with a certain quantity of any fluid which may chance to be present within the cavity of the head, chest, or abdomen; and having agitated the mixture for some time in distilled water, and filtered the liquid, taking care to keep the whole at a low temperature, proceed to the following experiments.
A. To a small quantity of the liquid add a few drops of a solution of caustic potass in alcohol.
B. To this, a few drops of a solution of sulphate of iron must be added, when a cloudy and reddish precipitate, of the colour of burnt Terra-Sienna will fall down.
C. Some sulphuric acid is now to be introduced into the tube, when the colour of the precipitate will instantly change to that of a bluish-green, which by a permanent contact with the atmosphere, becomes gradually of a beautiful blue, assuming at the same time a pulverulent aspect.
OR
A. Treat the filtered liquid with carbonate of potass.
B. Add a solution of sulphate of iron with a small quantity of alum: a precipitate, as in the former method, will fall down, which if treated by free sulphuric acid, will also become blue and pulverulent. During this latter part of the experiment, there is a disengagement of carbonic acid.
Evidence may be pushed still farther, and the existence of the Prussic acid proved in a most positive manner by decomposing the precipitate, above described, and which is a true Prussian blue, so as to separate the acid. For this purpose, heat the precipitate with an equal quantity of tartaric acid, in a glass retort, at the temperature of 150°, when the hydro-cyanic vapours will soon exhale from the mixture, and may be received in water.”[[442]]