Читать книгу Treatise on Poisons - Robert Sir Christison - Страница 15

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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.