CHAPTER I
DEFINITION OF A POISON—SALE OF POISONS—CLASSIFICATION OF POISONS—ACTION OF POISONS—GENERAL EVIDENCE OF POISONING—GENERAL TREATMENT IN CASES OF POISONING —GENERAL METHODS OF EXAMINATION FOR POISON
Toxicology is that division of Forensic Medicine which takes into consideration the modes and actions of poisons upon the living body, the treatment of their effects upon the body, and the methods of detecting them when occasion requires.
Definition of a Poison.—Neither the law nor medicine defines a poison. The popular definition is to be avoided, viz., that, a poison is a substance capable of acting injuriously on the body when taken or administered in a small dose.
Husband defined a poison as “any substance which, introduced into the system or applied to the body, is injurious to health and destroys life, irrespective of temperature or mechanical means.”
Taylor and Stevenson define a poison as “a substance which when absorbed into the blood is, by its direct action, capable of seriously affecting health or destroying life.”
There are substances, however, which do not require absorption into the blood in order to exert their deleterious action, e.g. the corrosive acids and alkalies; but, although the chief action is a local one in most cases, some absorption does take place and is evidenced in systemic effects, and are so classified as poisons differing from powdered glass, which acts mechanically only and is not a poison in the true sense of the word.
Winter Blyth considers that “a substance of definite chemical composition, whether mineral or organic, may be called a poison if it is capable of being taken into any living organism, and causes, by its own inherent chemical nature, impairment or destruction of function.”
According to Luff a poison is “a substance which, either by its direct action upon the skin or mucous membranes, or after its absorption into the blood, is capable of injuriously affecting health or destroying life.”
Letheby defines a poison as “anything which otherwise than by the agency of heat or electricity is capable of destroying life, either by chemical action on the tissues of the living body, or by physiological action from absorption into the system.”
The law does not recognise the manner in which the substance acts, nor the result; the legal standpoint is the intent of the administrator qua administrator. The law is as follows: “Whosoever shall administer or cause to be administered or taken by any person any poison or other destructive thing with intent to commit murder shall be guilty of a felony” (24 and 25 Vict. c. 100, sec. 11).
Section 22. “Whosoever shall unlawfully apply or administer to or cause to be taken by, or attempt to apply or administer to, or attempt to cause to be administered to or taken by, any person, any chloroform, laudanum, or other stupefying or overpowering drug, matter, or thing, with intent, in any of such cases, thereby to enable himself or any other person to commit, or with intent, &c., to assist any other person in committing any indictable offence, shall be guilty of felony.”
Section 23 enacts that, “Whosoever shall unlawfully administer to, or cause to be administered to, or taken by any other person, any poison or other destructive or noxious thing so as thereby to endanger the life of such person, or so as thereby to inflict upon such person any grievous bodily harm, shall be guilty of a felony.”
Section 24. “Whosoever shall unlawfully or maliciously administer to or cause to be administered to or taken by any other person any poison or other destructive or noxious thing with intent to injure or aggrieve or annoy such person shall be guilty of a misdemeanour.”
Section 25. “If upon the trial of any person charged with the felony above mentioned the jury shall not be satisfied that such person is guilty thereof, but shall be satisfied that he is guilty of the misdemeanour above mentioned, then, and in every such case, the jury may acquit the accused for such felony and find him guilty of a misdemeanour.”
Administration of Noxious Drugs.—The law throws on the medical witness the responsibility of the definition of a noxious thing, and whether it was given in excess, or liable to cause annoyance or injury to health. At a Bodmin Assize, Lord Chief-Justice Cockburn, after consultation with Mr. Justice Hawkins, delivered an important judgment on the subject. A man was charged with having administered cantharides with criminal intent. The judges ruled that there must not only be an administration of a noxious drug with a guilty intent, but the drug must have been administered in such quantities as to be noxious, whereas the dose here given was too small to be seriously deleterious. Distinction was drawn between a drug like cantharides, which is only noxious when given in excess, and strychnine, a well-established poison. Acquittal was therefore directed. In the case of R. v. Cramp, the prisoner was charged with having administered half an ounce of oil of juniper with intent to procure abortion. He was convicted, but appealed on the legal ground that the substance must be noxious in itself, and not only when given in excess. Lord Coleridge ruled that “if a person administers with intent to produce miscarriage something which as administered is ‘noxious,’ he administers a ‘noxious thing.’”
The Sale of Poisons.—The law, by the Pharmacy Act, 1868, and its amendments, restricts the sale of poisons to pharmaceutical chemists, chemists and druggists, and registered medical practitioners. The Acts define and indicate by schedule “Poisons within the meaning of the Act.” The Schedule of Poisons, as amended in the “Poisons and Pharmacy Act, 1908,” and “Additions to Schedule 1913,” is:
SCHEDULE OF POISONS
[As amended by Orders in Council]
Part I
Arsenic, and its medicinal preparations.
Aconite, aconitine, and their preparations.
Alkaloids.—All poisonous vegetable alkaloids not specifically
named in this schedule, and their salts, and all
poisonous derivatives of vegetable alkaloids.
Atropine, and its salts, and their preparations.
Belladonna, and all preparations or admixtures (except belladonna
plasters) containing 0.1 or more per cent. of belladonna
alkaloids.
Cantharides, and its poisonous derivatives.
Coca, any preparation or admixture of, containing 1 or more
per cent. of coca alkaloids.
Corrosive sublimate.
Cyanide of potassium, and all poisonous cyanides and their
preparations.
Emetic tartar, and all preparations or admixtures containing 1 or
more per cent. of emetic tartar.
Ergot of rye, and preparations of ergots.
Nux vomica, and all preparations or admixtures containing 0.2 or
more per cent. of strychnine.
Opium, and all preparations or admixtures containing 1 or more
per cent. of morphine.
Picrotoxin.
Prussic acid, and all preparations or admixtures containing 0.1 or
more per cent. of prussic acid.
Savin, and its oil, and all preparations or admixtures containing
savin or its oil.
Part II
Almonds, essential oil of (unless deprived of prussic acid).
Antimonial wine.
Carbolic acid, and liquid preparations of carbolic acid,
and its homologues containing more than 3 per cent.
of those substances, except preparations for use as
sheep wash or for any other purpose in connection with
agriculture or horticulture, contained in a closed
vessel distinctly labelled with the word “poisonous,”
the name and address of the seller, and a notice of the
special purposes for which the preparations are intended.
Chloral hydrate.
Chloroform, and all preparations or admixtures containing more
than 20 per cent. of chloroform.
Coca, any preparation or admixture of, containing more than 0.1
per cent. but less than 1 per cent. of coca alkaloids.
Diethyl-barbituric acid, and other alkyl, aryl, or metallic
derivatives of barbituric acid, whether described
as veronal, proponal, medinal, or by any other
trade name, mark, or designation; and all poisonous
urethanes and ureides. [Added March 12, 1913.]
Digitalis.
Mercuric iodide.
Mercuric sulphocyanide.
Oxalic acid.
Poppies, all preparations of, excepting red poppy petals
and syrup of red poppies (Papaver rhœas).
Precipitate, red, and all oxides of mercury.
Precipitate, white.
Strophanthus.
Sulphonal, and its homologues, whether described as trional,
tetronal, or by any other trade name, mark, or
designation. [Added March 12, 1913.]
All preparations or admixtures which are not included in
Part I. of this schedule, and contain a poison within
the meaning of the Pharmacy Acts, except preparations
or admixtures the exclusion of which from this
schedule is indicated by the words therein relating to
carbolic acid, chloroform, and coca, and except such
substances as come within the provisions of Section 5
of this Act.
Memorandum.—Special importance attaches to the last paragraph of Part II. of the schedule, as the effect of that paragraph is to include in Part II. many preparations and admixtures of vegetable drugs which contain poisonous alkaloids, although the drugs containing them are not specified in the schedule.
With those in Part I. a registration of the sale is compulsory, the purchaser must be known to or introduced by some person known to the vendor, and the purpose for which the poison is required, the date, the name and amount of the poison sold, the name and address of the buyer, and the entry must be signed by the purchaser and introducer. All substances in Parts I. and II. must be labelled by the vendor with a label bearing the name of the poison, the name and address of the seller, and the word “Poison”; but with those in Part II. no registration as in Part I. is required. In the sale of arsenic both the seller and purchaser must sign the entry, and the introducer must witness it. No arsenic can be legally sold to a person under the age of twenty-one years; nor may it be sold in quantities of less than 10 lbs. unless mixed with soot or indigo—one ounce of the former, or half an ounce of the latter, to each pound of arsenic. If quantities of over 10 lbs. be sold, and the soot or indigo would render it unfit for use in the way desired, then they may be omitted (Arsenic Act, 1851).
Classification of Poisons.—A good and scientific classification of poisons is still wanted. The following simple general division, depending upon the chief effect, may be taken as guides by the student:
| (a) Corrosives—Local corrosion. | ||
| (b) Irritants—Gastro-intestinal irritation. | ||
| (c) Neurotics—Altered action of the nervous system. | ||
| 1. INORGANIC | ||
| Corrosive—Sulphuric acid, &c. | ||
| Irritant—Arsenic, &c. | ||
| 2. ORGANIC | ||
| Irritant—Savin, Cantharides. | ||
| Affecting Brain—Opium. | ||
| Affecting Spinal Cord—Strychnia. | ||
| Affecting Heart—Digitalis. | ||
| Affecting Lungs—Carbonic acid. | ||
| (Guy.) | ||
| IRRITANTS | ||
| Mineral |  | Acid poisons—Sulphuric acid, &c. |
| Alkaline poisons—Caustic soda, &c. | ||
| Non-metallic—Phosphorus, Iodine, &c. | ||
| Metallic—Arsenic, Antimony, &c. | ||
| Vegetable—Savin, Elaterium, &c. | ||
| Animal—Cantharides. | ||
| NEUROTICS | ||
| Cerebral—Opium, Hydrocyanic acid, Alcohol. | ||
| Spinal—Strychnia, Nux vomica. | ||
| Cerebro-spinal—Conium, Belladonna, Aconite. | ||
| Cerebro-cardiac—Calabar bean, Digitalis. | ||
| (Taylor.) | ||
The subjoined classification is based upon that adopted by the late Professor Sir Douglas Maclagan. Where the poison acts in such a manner as to place it in two or more groups, I have fully described it in one, merely drawing attention to it under the others:
Action of Poisons.—Amid the difficulties which surround this subject, three points appear to have been clearly made out: (1) That it is necessary for all poisons to enter the blood before their specific action can be produced. (2) That poisons possess an elective affinity for certain tissues and organs. Thus, arsenic, however introduced into the system, as a rule attacks the stomach; and this peculiarity of action closely allies it to the poisons of typhoid, scarlet fever, smallpox, &c., which appear to have, respectively, an elective affinity for the glands of the intestines, the throat, and the skin. (3) That the habitual use of a poison in medicinal doses does not ensure a perfect toleration on the part of the system with regard to the action of the poison, for sooner or later a complete cachexia is produced, showing that the poisonous effect of the drug is not arrested.
Besides the above, there are also certain conditions connected with the action of poisons: (1) The poison is absorbed and distributed by the blood. (2) A portion is eliminated by the fluid secretions and excretions. (3) Another portion is for a time deposited in the tissues and organs of the body. These processes are of necessity simultaneous.
The channels of entrance and exit are as follows: Of entrance we have—(1) The blood-vessels as a result of wounds—more important in a physiological than a medico-legal question. (2) The skin and cellular membrane.—Absorption by the skin is modified by the condition of the part, and also by the form in which the drug is applied. Thus the skin of the arm-pits and groins is more absorbent than the palms of the hands. Watery solutions are not so effective as oily preparations, and the application of the drug in fine powder is more effectual than a watery solution of it. This is explained by the presence of a natural oily, unctuous substance on the skin, which prevents the direct contact of the watery solution, but if the solution be allowed to evaporate on the part, the substance thus left in minute division is then readily absorbed. The danger of allowing strong solutions of corrosive sublimate to evaporate on the head in the treatment of certain skin eruptions is thus explained. (3) The lungs and air-passages.—Absorption by these organs is most active, hence the intense rapidity in the action of aerial poisons. (4) The stomach and intestines.—Poisons introduced into the stomach or intestines take longer to arrive at the special organs on which they act than by the other channels of entrance. They are absorbed by the capillaries into the mesenteric veins, and before passing to the heart, by which they enter the general circulation, they pass through the liver, where they are in part excreted in the bile or deposited in the gland. The absorbing power of the stomach is modified by its fulness or emptiness, and poisons not soluble in water may be rendered so by the gastric secretion.
The avenue of entrance may materially modify the action, and some poisons which act rapidly when entering by a wound, are inert when taken into the stomach. Snake poisons when given by the mouth are entirely harmless. Hydrogen sulphide is more toxic when inhaled than when taken in solution. This, though true in some cases, does not always occur; and the inertness of these poisons, it has been suggested, may be due to the elimination of them being as rapid as their absorption, so that a poisonous dose never enters the circulation. The intestines absorb more rapidly than the stomach, and this must be borne in mind when administering powerful drugs per anum.
Of the channels of exit we have: (1) The kidneys. (2) The lungs. (3) The bile. (4) The milk. (5) The saliva. (6) Mucous membrane. (7) The skin.
We know not the cause, but certain poisons appear to select a particular route for their exit—thus iodide of potassium leaves by the urine; mercury and its salts by the saliva; arsenic and eserine, the active principle of the Calabar bean, in small quantities, by the stomach, &c. We are, however, prepared to show that all poisons must enter the blood before they produce their effects, and that almost simultaneously with the entrance of the poison into the blood a process of elimination begins, and that fatal effects depend upon absorption taking place more rapidly than elimination. On the amount also of the poison absorbed do its fatal effects depend, and not on the quantity actually taken. Whilst absorption and elimination are both going on, some of the poison is being deposited in the organs and tissues of the body. As proofs of these statements it has been shown that poisons have been detected in the blood, and that urine, saliva, and milk, fluids secreted from it, may contain portions of the poison taken, and produce dangerous symptoms when given to other animals. Poisons applied to the brain tissue, or to nerve trunks, do not produce symptoms, and the action of a poison may be arrested for a time by compressing by a ligature the main vessels of the limb under the skin of which the poison has been injected. After death no trace of the poison may be detected, the quantity taken being just sufficient to produce a fatal result, or elimination may be so rapid that, although death was directly due to the poison, any remains of its existence cannot be made out. This occurred in the case of Dr. Alexander, who died from an accidental dose of arsenic, all the arsenic being eliminated in seventeen days—in another fatal case, in seven days. (Taylor)
As evidence of the diffusion of poisons the following table may be of use:
| Physiological. | | Dilatation of the pupil in poisoning by | |
| belladonna, hyoscyamus, &c. | |||
| Contraction of the pupil in poisoning by | |||
| opium, Calabar bean. | |||
| Physical. |  | Taste.— | Bitter taste of the secretions. Strychnia, |
| picrotoxin. The milk of animals fed on wormwood | |||
| may become bitter; on colchicum, poisonous. | |||
| Smell.— | Prussic acid, tobacco, conium, &c. | ||
| Colour.— | Skin blackened by nitrate of silver, given | ||
| internally. | |||
N.B.—By the aid of the spectroscope the salts of lithium and thalium have been detected in the liver and other tissues.
Recapitulation of the Mode of Action of Poisons,
and the Causes which Modify their Action.
| MODE OF ACTION | ||
|---|---|---|
| I. LOCAL | ||
| 1. Corrosion of the part |  | Strong acid, alkali, &c. |
| to which the poison | ||
| is applied. | ||
| 2. Inflammation as the | | Arsenic, cantharides, &c. |
| result of irritants | ||
| applied to a part. | ||
| 3. Effects on the nerves | | Dilatation of the pupil by belladonna, |
| of motion and sensation. | tingling of the tongue and skin by | |
| aconite, paralysis by conium. | ||
| II. REMOTE | ||
|---|---|---|
| 1. Common—not to be distinguished from the effects of | ||
| injury or disease. | ||
| 2. Specific—peculiar to the poison itself. | ||
| (1) General—affecting the whole system.—Antimony. | ||
| (2) Partial—acting on a particular organ.—Antimony | ||
| MODIFYING CAUSES | ||
| 1. Quantity. |  | 1. Quantity of the poison increases its rapidly |
| fatal action. | ||
| 2. Action changed by the size of the dose. Thus, | ||
| oxalic acid in large doses acts as a corrosive; in | ||
| small doses on the heart, brain, or spinal cord. | ||
| 2. Form. | | Solubility increases the activity of poisons. |
| Chemical Combinations.—Baryta is poisonous, | ||
| sulphate of baryta is inert. | ||
| Mixture.—Dilution may retard or accelerate | ||
| the action of a poison.[19] | ||
| 3. Point of application—Skin, lungs, mucous and serous membranes. | ||
| 4. Condition of the body. | | Habit—generally lessens the action of |
| poisons, e.g. arsenic-eater, morphine | ||
| taker, morphine taker. | ||
| Idiosyncrasy—increases or may lessen the | ||
| action of poisons. | ||
| Disease—generally lessens, but in some | ||
| cases increases the action of poisons. | ||
GENERAL EVIDENCE AND
DIAGNOSIS OF POISONING
It will now be necessary to consider briefly the general evidences of poisoning, in order to determine whether a death alleged to be due to poison is not really the result of disease. For convenience of description, this subject will be divided into five sections:
- 1. Evidence from the Symptoms.
- 2. Evidence from the Post-mortem Appearances.
- 3. Evidence from Chemical Analysis.
- 4. Evidence from Experiments on Animals.
- 5. Moral Evidence.
1. Evidence from the Symptoms.—As a general rule the symptoms come on suddenly while the person is in apparent health, except in cases of slow poisoning, when the poison may be so administered by frequently repeated and small doses as to simulate disease, and the physician is more easily misled than when a single large dose is given. In cases of suspected homicide this suddenness in the accession of the symptoms is particularly to be noticed, and we may have to decide as to the probabilities of accident, suicide, or homicide. Here collateral evidence must be our guide. The slowness, obscurity, and irregularity of the symptoms are more in favour of homicide than either accident or suicide. But it must also be borne in mind that the invasion of many diseases is sudden, as is the case with cholera, gastritis, and some others.
Certain conditions of the system more or less modify the effects of some poisons. Thus, sleep delays the action of arsenic; and this may also be the case with other poisons. Intoxication has also been said to exert a retarding power over the action of certain poisons. This is probably more apparent than real, the fact being that the symptoms in the cases observed are masked.
Much more important, however, is the influence of disease. Large doses of opium are well borne in mania, delirium tremens, dysentery, and tetanus; whereas it is well known that even small doses of mercury in cases of Bright‘s disease of the kidney, or in children recovering from any of the eruptive fevers, have produced dangerous salivation.
The symptoms of poisoning go on from bad to worse in a steady course; but there may be remissions, followed, under treatment, by their entire disappearance, no ill effect remaining. Remissions are most likely to occur in slow poisoning with the metallic irritants, from fear of detection or cunning on the part of the poisoner to imitate the progress of disease. In nervous affections, all the symptoms must be taken into consideration, and these will be found to differ from those of any known poison. The history of the case should also have due attention paid to it.
In poisoning, the symptoms appear soon after food or drink has been taken. This is open to the objection that apoplexy has occurred immediately after a meal. The probative value of the above statement is, however, increased if several persons have been similarly affected after partaking of the same dish, especially if the symptoms followed within a short time—under four hours—of the meal. But it must also be remembered that all persons are not affected alike by the same poison. Again, the diagnostic value is weakened if it can be proved that the person or persons affected have taken nothing in the way of food for two or three hours previously.
The flesh of animals poisoned by accident, or intentionally, may seriously affect those who eat it.—As a case in point may be mentioned the injurious effects produced in some persons who had partaken of the Canadian partridges imported to this country some years ago, and which had probably eaten some poisonous berries during the severe winter of that year.
Poisons may be introduced into the system otherwise than by the mouth; that is, they may be placed in the vagina or rectum, or inhaled when volatile poisons are used. Sometimes a poison has been introduced into the medicine, or a poisonous draught substituted for the one prescribed. In any case, where suspicious symptoms suddenly occur, the poison has most probably been taken in from half an hour to an hour previously, and it is of special importance to note the period of time that may have elapsed between the accession of the symptoms and the last meal, or administration of medicine.
When called in to a case of suspected poisoning, and in many cases where no suspicion at the time arises, the medical attendant should pay attention to the following points:
1. The time of the occurrence of the symptoms, and their character.
2. The time that has elapsed between their commencement and the last meal, dose of medicine, &c.
3. Have the symptoms continued without intermission or remission, and in an aggravated form, till death?
4. The order of their occurrence.
5. The previous health or illness of the patient.
6. Have the symptoms any relation to a particular meal or article of food, &c.?
7. If patient has vomited, have the vomited matters, especially the first, been carefully preserved?
8. Preserve all vomited matters, food, medicines, &c.
9. How many were at the meal, and was what was taken common to all, or only taken by a few?
2. Evidence from Post-mortem Appearances.—The morbid appearances found in cases of poisoning will be treated more in detail when each poison, or group of poisons, comes to be separately considered. A caution may be given here against allowing the post-mortem signs of disease or external injury to exclude the idea of poisoning; for death may to all appearance be the result of disease or injury, and yet be caused by poison. An attention to the post-mortem appearances is important in all cases; for in many instances, where the symptoms were unknown to the experts at the time the inspection was made, they were subsequently found to correspond with the morbid changes which the autopsy revealed. The normal appearance of the stomach is white or nearly so, except during digestion, when it is reddened; yet we may sometimes come across cases in which the mucous membrane of this organ may be found so reddened as to lead to a suspicion of poisoning. The knowledge of this fact, and the absence of symptoms, will prevent an error in diagnosis. Ulceration from disease and from irritant poisoning must be distinguished. In that due to disease, the ulcers formed are, as a rule, small and circumscribed; in those from poison, there is diffused inflammatory redness over other parts of the stomach, and even in the intestines; and the poison, as in the case of arsenic, may be found adhering to the sides of the ulcer. Ulceration is more frequently the result of disease than of the action of poisons. Perforation of the stomach or intestines may be due to ulceration or to corrosion. The condition of the mouth and gullet will help the diagnosis. The appearance of the ulcer and the parts around it, together with the hints just given, must guide the diagnosis. Of post-mortem softening little need be said, beyond stating that it very rarely occurs, and is of course not preceded by symptoms. (For the diagnosis between inflammatory redness of the intestines and post-mortem staining, see page 45.)
3. Evidence from Chemical Analysis.—The objects of a chemical analysis are to determine: (1) The presence and nature of the poison. (2) The proportion or quantity of the poison taken. (3) The solution of certain questions connected with the administration of the poison.
The detection of poison in the body is of course the most important proof of poisoning; but it may be suggested that the poison was introduced after death, which, to say the least, is a most ingenious line of defence, but which, at the same time, must be held to be highly improbable, and impossible if found deposited in one or more of the solid organs. Again, granting that poison has been taken, is it the cause of death? This question may arise when injuries are found on the body, and it then becomes a matter of importance to know something of the symptoms which preceded death, and the morbid appearances found after death. The case of the girl who took arsenic to escape a beating by her father is a case in point. The father was tried for causing the death of the girl by undue severity, but it was subsequently shown that arsenic self-administered was the true cause of death. The poison may disappear from the body. This disappearance may be effected by vomiting, purging, or by the urine, or the poison may become absorbed and decomposed. The person poisoned may live sufficiently long to allow of the entire elimination of the poison, and yet die of the induced exhaustion. (See case of Dr. Alexander, ante.)
Some poisons, especially those which are sparingly soluble, are with difficulty removed from the stomach, even by the most incessant and violent vomiting. This is notably the case with arsenic, which adheres to the mucous coat of the stomach with considerable tenacity. But even after all traces of the poison have left the stomach, it may be detected in the solid viscera.
Temporary deposit of poison in the organs or tissues (Taylor): (1) The Liver. (2) The Kidneys. (3) The Spleen. (4) The Heart. (5) The Lungs. (6) The Muscles. (7) The Brain. (8) The Fat. (9) The Bones.
With regard to arsenic, the following table, taken from Taylor, is of importance, as showing the amount of the poison which may be found in the liver at certain intervals:
| After taking the Poison. | Total Weight of Arsenic. | |
| In | 5½ to 7 hours | 0.8 grains. |
| 8¾ hours | 1.2 | |
| 15 hours | 2.0 | |
| 17 to 20 hours | 1.3 | |
| 10½ days | 1.5 | |
| 14 days | 0.17 | |
| 17 days | nil | |
Is it necessary that the poison should be found in the body or in the evacuations to lead to a conviction for poisoning? On this point, Christison was of opinion that if the symptoms, post-mortem, appearances, and moral evidence are very strong, it is not necessary that the poison be found in order to establish a charge of poisoning. This opinion was also supported by the late Dr. Geoghehan, Professor of Medical Jurisprudence in the Royal College of Surgeons, Ireland, and was also virtually acted upon in the case of Palmer, where the non-detection of strychnia was strongly dwelt upon by the counsel for the defence, but without success. Many of the vegetable poisons almost defy detection, except by the symptoms, post-mortem appearances, and some experiments on animals of doubtful value. The detection of poison in the food taken, or in the vomited matters, is of great importance; but it is of still greater importance if it can be found in the urine, drawn from the bladder, this being a proof that it has passed through the system. Here again a caution is necessary—for it must be remembered that poisoning may be feigned or imputed—the poison being mixed with the food and evacuations, and an innocent person accused.
The following suggestions should be carefully considered by every analyst when substances are sent to him for examination:
He should carefully note when and from whom the substances were received; in what state they were received—secured, or exposed—the number of articles, and whether properly labelled. He must make the analysis himself, and state where it was made. The character and nature of the substances examined should be noted, and he must be prepared to give an outline of the methods or processes used for their determination. He must also be able to guarantee the purity of his reagents, and be prepared to answer the following questions:
- 1. Is the poison free or combined?
- 2. What is the strength and quantity found?
- 3. Could the poisonous substance exist naturally?
- 4. How much of the poison found is a fatal dose?
- 5. If no poison is found, is there anything noxious
- or injurious to health?
The analyst may have the following submitted to him for examination: (1) Substances found on the accused, or in the room, or on the person of the deceased. (2) Articles of food. (3) Vomited matters, urine, &c. (4) Contents of the stomach. (5) Solid organs of the body.
He may also have his results called in question for the following reasons: (1) Purity of his reagents. (2) Faulty processes. (3) Hasty conclusions. (4) Experiments on animals.
Death may undoubtedly be due to the action of a poison, and yet its presence may fail to be detected, due to—(1) The nature of the poison-strychnia, hydrocyanic acid, &c. (2) Vomiting and purging. (3) Absorption and elimination. (4) Decomposition—phosphorus, chloral hydrate, chloroform. (5) Smallness of the dose.
(For directions for conducting a post-mortem examination in cases of poisoning, see page 61.)
4. Evidence from Experiments on Animals.—The evidence derived from experiments on animals with the contents of the stomach and vomited matters must not be too implicitly trusted, as these may give rise to vomiting and other symptoms when no poison is present. All animals are not alike affected with man by the same poisons; and it appears that the dog and the cat are the only animals that at all approach man with regard to the effects produced. Experiments on the lower animals are useless to decide—(1) The fatal dose of any poison. (2) The rate of absorption, deposition, or elimination of poisons. (3) The rapidity of the action of certain poisons.
In the case, however, of some vegetable poisons, the effects produced on animals by a portion of the substance taken by the person suspected of having been poisoned, may afford corroborative evidence of poisoning. In the case of Lamson, executed for poisoning his brother-in-law with aconite, experiments on animals formed the chief evidence against the accused.
5. Moral Evidence.—The moral evidence of poisoning is generally furnished by the common witnesses of the Crown; but the value of this kind of evidence, in many cases, can only be fully appreciated by a medical witness. To render this part of the subject as complete as possible, a few remarks may not be out of place. The suspicious conduct of the prisoner before and after the event, the recent purchase of poison, the mode of administration, the object of the prisoner in getting rid of his supposed victim, and the fact of several persons being alike affected, should be carefully noted down. The anxiety evinced during the illness of the deceased, and the hurry in the funeral arrangements, showing an over-anxiety to remove all traces of his guilt, are suspicious. The probability of suicide is weakened by the state of the mind and the nature of the dying declarations of the deceased. In the case of a person indicted for poisoning, evidence to show motive in another case is admissible. (R. v. Geering, 18 L.J. [M.C.] 215; R. v. Heeson or Johnson; R. v. Garner, 3 F. & F. 681.)
Lastly, it remains to be considered—
What is the duty of a Medical Man who suspects the Action of Poison in a Patient on whom he is in attendance?
In the case of R. v. Wooler, Baron Martin, who tried the case, in his charge to the jury, stated that, in his opinion, the medical men in attendance ought, “when the idea of poisoning struck them, to have communicated their suspicion to the husband, if they did not suspect him; and if they did suspect him, they ought to have gone before a magistrate.” Suppose they had acted as the learned judge suggested, and spoken to the husband, who, had he been guilty, would in all probability have desisted from his terrible design for a time, then a great criminal would have been let loose on society, and without punishment. Then, again, had they applied to the magistrates, the delay caused by the indecision of the magistrates how to act in so delicate a case would have allowed the criminal to remove all traces of his design, and the means of testing their suspicions would have been lost; and, along with this, would have been lost the professional character and fortunes of the authors of the investigation. “There is a third course,” said the late Sir R. Christison, “and in my opinion it is the fittest of all: When the medical attendant is satisfied of the fact of poisoning, he should communicate his conviction to the patient himself. His predicament, in every other way, is so embarrassing, that he ought not to be deterred by the chance of injury to his patient from making so dreadful a disclosure.” (See an account of the same course being adopted in the case of Mr. Blandy by his physician, Dr. Addington, reported in Howell‘s State Trials, vol. xviii.)
Table giving the names of Diseases, the Symptoms of which resemble those the result of Irritant Poisons, together with such points of difference as may assist in distinguishing the one from the other:
Irritant Poison.—Symptoms of violent irritation in one or more portions of the alimentary canal. Pricking and burning of the tongue and mouth, and intense thirst, frequently accompanied with great constriction in the throat. Great abdominal pain and tenderness. Vomiting and purging are also usually present. The skin is hot and cold at intervals; the pulse small, frequent, and irregular. In the last stage the skin may become icy cold. An acrid, metallic, or burning taste in the mouth precedes the vomiting. The vomit and alvine discharges are generally mixed with blood. Death occurs in from six hours to two days and a half.
Cholera.—Extreme and sudden prostration. The breath is cold to the hand in the last stages. The body is cold, shrivelled, and livid, or of a leaden hue. Vomiting and purging are present; the former is never bloody, the latter resembling rice-water. The thirst is intense, and in this particular alone resembles the effects of irritant poison. Death in from one to two days, or even less.
Summary of the General Evidence of Poisoning,
in a Tabular Form
| Poison. | Natural Causes. |
| 1. The symptoms come on suddenly, | 1. Many diseases come on |
| and rapidly progress. | suddenly—cholera, gastritis, |
| &c—and run a rapid course to | |
| a fatal termination. | |
| 2. The symptoms begin while | 2. Some acute diseases begin |
| the person is in sound health. | under like circumstances. |
| 3. The symptoms of poisoning | 3. This is also the case with |
| go on from bad to worse in a | many common diseases. |
| steady increase. | |
| 4. Uniformity in the nature of | 4. The uniformity of the symptoms |
| the symptoms. | is common to many diseases; |
| but in some cases the absence | |
| of uniformity may be a proof | |
| of disease. | |
| 5. The symptoms come on | 5. Apoplexy, colic, cholera, and |
| immediately after a meal. | some other diseases may follow |
| a meal. But the fact that some | |
| hours have elapsed since the | |
| last meal is against the | |
| probability of poisoning. | |
| 6. Several persons are attacked, | 6. As a general principle it may |
| after partaking of the same | be stated that there is no |
| meal, with the same symptoms. | disease likely to attack |
| several persons at once, but | |
| there are cases on record of | |
| this having occurred. | |
| 7. Poison found in the food, | 7. Poison may be mixed with food, |
| vomited matters, urine, &c. | &c, in cases of imputed poisoning. |
English Cholera.—In this disease all the symptoms of irritant poisoning are present. Pain in the belly, and vomiting. But in this disease the vomit and alvine discharges are never bloody, most frequently bilious. An acrid taste in the mouth and throat succeeds the vomiting. This is due to the acrid nature of the vomited matters. The stools contain bile in English cholera; in irritant poisoning, sometimes blood. Death is rare within three days.
Gastritis.—Acute idiopathic gastritis is so rare in this country as scarcely to need description. Most of the cases recorded of acute gastritis have been found to be due to irritants. We must, therefore, consider the period and order of the occurrence of the symptoms in relation to the last meal. Costiveness of the bowels would point to the presence of gastritis or enteritis, violent purging and vomiting to irritant poisoning.
Enteritis.—Though more common than gastritis, enteritis is a rare disease. The bowels are generally confined. Tubercular and aphthous inflammation of the intestines may simulate irritant poisoning, especially chronic poisoning by arsenic. The post-mortem and a chemical analysis will reveal the true cause of death.
Peritonitis.—In the early stages of the disease vomiting is rare, and constipation is the rule, with marked tenderness over the whole abdomen. The morbid appearances in the peritoneum are seldom caused by irritants.
Perforation of the Stomach.—The symptoms supervene immediately after a meal; the pain, which is very acute, gradually extending over the abdomen. In most cases the patient has suffered for some time previously from dyspepsia.
Hernia.—Examine the seat of pain, the cause will be soon detected. But an omental hernia may be present, giving rise to twisting pain at umbilicus.
Intussusception of the Bowels.—Pain, sudden and confined to one spot below the stomach. Vomiting is present without purging, thus differing from diarrhœa and cholera. After a time the vomit becomes fæcal.
Colic.—May be confounded with poisoning by the salts of lead. If lead be taken in large doses, it produces the symptoms common to irritant poisons added to those of colic. In chronic lead poisoning, the blue line round the gums, the aspect of the patient, and history of the case, will point to the true cause of the symptoms. Lead colic is also generally accompanied with extreme depression of spirits.
Rupture of Internal Organs.—Rupture of the stomach, duodenum, gall-bladder, and impregnated uterus, is of rare occurrence. The autopsy will show the true cause of death.
Table giving the names of Diseases the Symptoms of which resemble those the result of Narcotic Poisoning, together with such points of difference as may assist in distinguishing the one from the other:
Narcotic Poisoning.—Giddiness, headache, drowsiness, and considerable difficulty in keeping awake. Paralysis of the muscles, convulsions, ending in profound coma and death. The symptoms of narcotic poisoning begin not later than an hour, or at most two hours, after the poison is taken, except in the case of poisonous fungi and spurred rye, when a day or two may elapse. The symptoms of narcotic poisoning advance gradually. The person may, in most cases, be roused from the deepest lethargy. The pupil in opium poisoning is, as a rule, contracted. Recovery seldom occurs after twelve hours; in most cases, death takes place in six or eight hours—the shortest time being three hours.
Apoplexy.—In some cases apoplexy is preceded by warning symptoms—headache and giddiness. As a rule apoplexy is a disease of old age, and of stout, plethoric people. If the symptoms do not come on for some hours after food or drink has been taken, this disease is to be suspected; but it may occur at or immediately after a meal, too soon to be the result of the action of narcotics—ten to thirty minutes always elapsing before these poisons act. Apoplexy generally comes on suddenly, coma at once present. It is seldom possible to rouse the person when the sopor of apoplexy is fully developed. The pupils in apoplexy are usually unequal or dilated; but should the effusion of blood take place into the pons Varolii, the pupils may be contracted, hence closely simulating opium poisoning. Apoplexy may last for days, or death may occur in an hour.
Epilepsy.—Loss of consciousness and presence of convulsions mark this disease; and in these it resembles poisoning by prussic acid. Epilepsy is in most cases a chronic disease. Warnings—aura epileptica—are often present. The fit begins violently and abruptly. The paroxysm generally lasts for some time, and death rarely occurs during the first attack.
Table showing Points of Difference in the Action of
Corrosive and Irritant Poisons
| Corrosives. | Irritants. |
| 1. Destruction of the parts to | 1. Irritation of the parts to |
| which they are applied. No | which they are applied |
| remote action on the system. | producing inflammation. |
| Remote action present in | |
| most of the irritants. | |
| 2. Symptoms supervene immediately | 2. Symptoms may rapidly |
| they are swallowed, and consist | supervene after they are |
| of a burning, scalding pain | taken, or some delay may |
| elt in the mouth, gullet, and | occur, due to the state of |
| stomach. | concentration or dilution |
| of the poison. Pain in | |
| the stomach and bowels, | |
| more or less severe, is | |
| always present with the | |
| other signs of irritation. | |
| 3. Death may result from— | 3. Death may result from— |
| (1) Shock. | (1) Shock. |
| (2) Extensive destruction of | (2) Irritation, causing |
| the parts touched. | |
| (3) Starvation. | (3) Protracted suffering. |
| (4) Suffocation, the result of | (4) Starvation. |
| œdema, or spasms due to | |
| acid in larynx. | |
| 4. Post-mortem appearances: | 4. Post-mortem |
| corrosion and extensive | appearances: irritation |
| destruction of tissue. | and signs of inflammation, |
| ulceration, &c. |
GENERAL TREATMENT OF CASES
OF POISONING
The principal modes of procedure are as follows:
1. To remove the poison from the digestive tract, or neutralise it or render it insoluble by the administration of suitable antidotes.
2. To overcome the effects of that which has been absorbed.
3. To promote its elimination.
4. To alleviate dangerous symptoms, and endeavour to keep the patient alive until the effects of the poison have passed off.
To forcibly empty the stomach, emetics may be administered or other means used to induce vomiting, or the stomach pump or tube may be employed.
Suitable emetics are sulphate of zinc in thirty-grain doses dissolved in warm water, a dessert-spoonful of mustard in half a pint of warm water, ipecacuanha wine in tablespoonful doses, copious draughts of hot water. Tartar emetic and sulphate of copper should be avoided, except in cases of phosphorus poisoning, when the latter may be used. The hypodermic injection of ⅒ grain of apomorphine is a very useful emetic, especially in cases of narcotic poisoning. Irritation of the fauces with the finger or a feather promotes vomiting, and may be useful in the absence of an emetic.
The stomach tube or pump is most useful in that it is under the control of the operator and enables him to thoroughly wash out the stomach. After passing the tube, previously lubricated with vaseline or glycerine, through the œsophagus down to the stomach, a pint of warm water should be first injected before withdrawing any of the contents. By alternate injection of water and its withdrawal, the stomach may be efficiently cleansed, and at the same time solutions of suitable antidotes may be passed into it. It must be remembered that neither the stomach pump, syphon tube, nor emetics, are to be used in cases of poisoning with corrosives, with the exception of carbolic acid. The tube should be used with great caution in cases of irritant poisoning.
Antidotes are remedies which counteract the effects of poisons. They act mechanically, e.g. flour and water, chalk mixture; chemically, as magnesia and chalk in mineral acid poisoning, alkaline sulphates in lead and barium poisoning; and physiologically, as antagonists, such as morphine and atropine, atropine and physostigmine, strychnine and chloral hydrate.
To counteract the effects of the portion of the poison absorbed, special treatment is necessary: purges and diuretics may be called for; artificial respiration may be necessary; cardiac depressants require cardiac stimulants; the cold douche as a restorative and external warmth are desirable in certain cases. Sedatives may be administered to alleviate convulsive seizures. Tracheotomy may be required in cases with laryngeal complications; and pain, exhaustion, excessive vomiting or purging are to be treated by appropriate remedies.
EXAMINATION OF THE CONTENTS OF THE
STOMACH, VISCERA, ETC., FOR POISON
The number and condition of the vessels received should be noted and copies made of any affixed labels.
The appearance, smell, colour, and reaction to test paper of the contents should be noted, and their weights and volumes determined. All jars, wrappers, labels, and seals should be preserved for future reference.
The stomach contents should be carefully examined in reference to their nature, colour, and smell, and the presence or absence of any abnormal constituents. The mucous membrane of the stomach should be examined with the naked eye and by the aid of a lens, the surface washed with distilled water, and the washings added to the contents.
There is often some clue as to the nature of the poison afforded, and the investigation should be made for it first; the presence or absence of other poisons, however, must be determined. If there be no clue, then a systematic examination must be carried out. The poison must be looked for not only in the contents of the stomach, but in the viscera as well; it must be remembered that poison may be introduced into the stomach after death.
Volatile poisons, such as alcohol, chloroform, prussic acid, may be separated by distillation after acidulation with tartaric acid. Arsenic is best separated by drying the organic material, and distilling after adding strong hydrochloric acid.
Other metallic poisons may be tested for, with or without destruction of organic matter. To destroy the organic matter, the moist method is the one in general use: After reducing the contents of the stomach or the viscus to a pulp, they are mixed with distilled water to the consistency of thin gruel, and placed in a flask with some crystals of potassium chlorate—half an ounce to each pound of the liquid. Pure hydrochloric acid is added, and the flask gently heated on a water bath, a mixture of chlorine and oxides of chlorine is given off and gradually breaks up the organic matter, converting at the same time any mineral poison present into the chloride. This procedure is followed until the material becomes quite limpid, more chlorate or hydrochloric acid may be added if necessary. It is then transferred to an evaporating dish and heated on the water bath until the smell of chlorine disappears. It is then filtered while hot, to allow chloride if present to pass through; a stream of sulphur dioxide is passed through the filtrate when cold, to reduce any metals present to a lower state of oxidation. Silver chloride will not pass through the filter in this process, so it has to be dealt with in a special manner.
In making a systematic analysis, volatile poisons must be tested for first, then ascertain the presence or absence of alkaloids, after which the inorganic poisons must be dealt with.