Another mode in which the chemical part of the inquiry may contribute to discover the individual who administered the poison is by a comparative examination of the persons of the deceased and the accused. The following very pointed illustration has been published by MM. Ollivier and Chevallier of Paris.—A woman who lived on bad terms with her husband was found dead on a roadside the morning after having been seen drunk in his company in the neighbourhood. The mouth, throat, and gullet were proved by a careful analysis to be corroded with nitric acid, the stains and traces of which were also found on various parts of her dress, and on the hair, neck, and arms, but not on her hands, and not lower down the alimentary canal than the upper fourth of the gullet. Ollivier, suspecting from these appearances, that she had not taken the acid voluntarily, requested to see the husband; whereupon there were found on his coat, trousers, and hands, a great number of stains, which, like those on the deceased, were proved by chemical analysis to have been produced by nitric acid. Here it was scarcely possible to avoid inferring, that the man got these stains while endeavouring to force his intoxicated wife to take the poison Marks of nail scratches were also observed round the mouth and on the throat; whence it was reasonably inferred, that, having failed in his original plan, he had suffocated her with his hands.[[123]]
While these illustrations are given of the conclusiveness of the chemical evidence in fixing the administration of poison on a particular individual, it is essential likewise to observe that the same kind of evidence may be at times equally conclusive of the innocence of a person unjustly suspected. This obvious and important application of a chemical inquiry is forcibly suggested by the following particulars of an incident related by M. Chevallier:—An individual was accused by a woman of having tried to poison her; and she represented that he had put the poison into her soup, while it stood from one day to another in an iron pot. On making a careful analysis of some of the soup which remained, Chevallier found it so strongly impregnated with copper, that, supposing the sulphate was the salt mixed with the soup, ten ounces must have contained twenty-two grains. It then occurred to him, that it was important to examine the iron pot, in which the poisoned soup was represented to have been kept; for the probability was that a large quantity of the copper, if any salt of that metal had really been contained in the soup, would have been thrown down by the superior affinity of the iron, and consequently that a coppery lining would be found on the inside. He was led, however, to anticipate that no copper would be found there, because there was no iron dissolved in the soup, as would have been the case if copper had been precipitated from it by the iron of the pot. And accordingly he not only found no copper lining the inside of the pot; but likewise, on following the process described by the accuser as the one pursued in cooking the soup and in subsequently poisoning it, he satisfied himself by express trial that there was nothing in the circumstances of the case which could have prevented the iron from exerting its usual action on the salts of copper. These conclusions, coupled with certain facts of general evidence, proved substantially that the suspected person had nothing to do with the crime charged against him; and he was therefore discharged.[[124]] A case somewhat similar will be related under the head of Imputed Poisoning.
In the second place, evidence as to the person who administered the poison may be procured by considering the commencement of the symptoms, in relation to the time at which particular articles have been given in a suspicious manner by a particular individual. The import of facts of this nature can be properly appreciated only by the medical witness; for he alone can be acknowledged as conversant with the symptoms which poisons produce, the intervals within which they begin to operate, and the circumstances in which their operation may be put off or accelerated.
Few cases will occur in which it is not possible to procure evidence of the kind, when diligently sought for. It is often too very decisive in its operation on judicial proceedings. In the case of Margaret Wishart tried at the Perth Spring Circuit in 1827 for poisoning her blind sister, a man who lodged with the prisoner and cohabited both with her and with the deceased, appeared at first from general circumstances to be implicated in the crime. He had left the house, however, on the morning of the day before that on the evening of which the deceased took ill; and he did not return till after her death. Now her illness commenced suddenly and violently; and arsenic was the poison which caused it.[[125]] It was quite clear, therefore, that the poison could not have been administered, at least in a dangerous dose, so early as the day before she was taken ill; and such I stated to be my opinion, on a reference from the Lord Advocate. The evidence being also otherwise insufficient, the man was set at liberty. In the case of Mrs. Smith tried here in February of the same year, this branch of the evidence was made the subject of question under more doubtful circumstances. The deceased certainly died of poisoning with arsenic, and the prisoner was strongly suspected of being the poisoner for many reasons, and among others because, on the evening before the morning on which the deceased took ill, the prisoner gave her in a suspicious manner a white-coloured draught. Here the possibility of the draught having been the cause of the symptoms must be admitted. But as they did not appear for eight hours after the draught was taken, I stated in my evidence that it was improbable the dose, if it contained arsenic at all, contained a quantity sufficient to cause the violent symptoms and death which followed.[[126]]
The correspondence in point of time between the appearance of symptoms of poisoning, and the administration of suspicious articles by an individual, constitutes still more decisive proof in a set of cases, in which it is of great value, as the chemical evidence is generally defective,—namely, where poisoning is attempted with repeated moderate doses. If the several renewals or exacerbations of illness correspond with the periods when suspicious articles have been given by the same individual, the circumstantial evidence of the administration may be even tantamount to direct proof. Thus, on the trial of Miss Blandy for the murder of her father, it was proved, that Mr. Blandy on several occasions, after the prisoner received certain suspicious powders from her lover, was taken ill with vomiting and purging; and that on two occasions recently before his death, when he got from his daughter a bowl of gruel which contained a gritty sediment, he was attacked after a very short interval with pricking and heat in the throat, mouth, stomach, and bowels,—with sickness, vomiting, gripes, and bloody diarrhœa.[[127]] Here the proof of administration by the prisoner was complete.
These examples will show how the evidence of a particular person’s criminality may be affected by the relation subsisting in point of time between the commencement of the symptoms and the suspicious administration of particular articles. But farther, the special period at which the symptoms begin may even at times supply strong evidence of his instrumentality, although there may be no direct proof from general evidence of his having been concerned in administering anything whatever in a suspicious manner. This statement is well exemplified by the case of Mrs. Humphreys, who was convicted at the Aberdeen Autumn Circuit in 1830 for poisoning her husband, by pouring sulphuric acid down his throat while he was asleep. It was clearly proved, as will be seen under the head of sulphuric acid, that the deceased died of this poison; and the administration was brought home to the prisoner in the following singular manner. The only inmates of the house were the deceased, the prisoner, and a maid-servant. The deceased got a little intoxicated one evening at a drinking party in his own house; and after his friends all left the house, and the street-door was barred inside, he went to bed in perfect health, and soon fell fast asleep. But he had slept scarcely twenty minutes, when he suddenly awoke with violent burning in his throat and stomach; and he expired in great agony towards the close of the second day. Now sulphuric acid, when it occasions the violent symptoms observed in this instance, invariably excites them in a few seconds, or in the very act of swallowing. It was, therefore, impossible that the man could have received the poison at the time he was drinking with his friends; and as he knew he had not taken any thing else afterwards, and it was fully proved that he had been asleep before his illness suddenly began,—it followed that the acid must have been administered after he fell asleep, the accomplishment of which was rendered easy by a practice he had of sleeping on his back with his mouth wide open. But, after he gave the alarm, the door was found barred as when he went to bed. Consequently no one could have administered the poison except his wife or servant; and it was satisfactorily proved, that no suspicion could attach to the latter. Such was one of the principal train of circumstances, which, as it were by a process of elimination, led to the inference that the wife was undoubtedly the person who administered the poison. Other circumstances of a similar tendency were also derived from the medical evidence; but these it is unnecessary to detail at present. I have related the particulars of the whole case fully elsewhere.[[128]] The prisoner strenuously denied her guilt after being sentenced, but confessed before her execution.
4. The next article in the moral evidence relates to the intent of the person who is proved to have administered poison. When the administration is proved, little evidence is in general required to establish the intent. It is sufficient that the giver knew the substance administered was of a deadly nature; and in regard to any of the common poisons this knowledge is sufficiently constituted by his simply knowing its name.
In some cases, however, the exact nature of the poison is not established with certainty; and then something else may be required to prove the prisoner’s knowledge, and through that knowledge his intent. In the case of Charles Munn, formerly alluded to [p. [50]], arsenic was the poison presumed to have been taken by the deceased. But the purchase or possession of it by the prisoner was not for some time satisfactorily established; neither was there any chemical evidence, the deceased having lived forty days and upwards after taking the poison. It was proved, however, that whatever it was which had been administered, the prisoner knew very well that what he gave was deleterious; because he persuaded the deceased, who was pregnant by him, to take it by assigning to it properties which no drug either possesses, or is so much as thought by the vulgar to possess. On one occasion he persuaded her that it would show whether she was with child, and on another that it would prevent people from knowing she was with child. In such cases, then, good evidence may be derived from the arguments used by the giver to persuade his victim to take the poison; and sometimes, as in the instance now mentioned, it will lie with the medical witness to inform the court whether or not the reasons assigned are false.
Sometimes it has been pleaded by the prisoner that he gave the poison by mistake. In all such cases, if he descends to particulars, which he cannot help doing, there is every likelihood that the falsehood of the defence will be made evident by the particulars of the story not agreeing with other particulars of the moral or medical evidence. At present it is only necessary to allude to inconsistencies in his story with the medical facts. No general rules can be laid down on the method of investigating a case with a view to evidence of this kind: I must be satisfied with an illustration from an actual occurrence. On the trial of Mr. Hodgson, a surgeon, at the Durham Autumn Assizes in 1824, for attempting to poison his wife, it was clearly proved, that pills containing corrosive sublimate, and compounded by the prisoner, were given by him to her in place of pills of calomel and opium, which had been ordered by her physician. But it was pleaded by him, that, being at the time intoxicated, he had mistaken, for the shop-bottle which contained opium, the corrosive-sublimate bottle which stood next it. This was certainly an improbable error, considering the opium was in powder, and the sublimate in crystals. But it was not the only one which he alleged he had committed. Not long after his wife took ill, the physician sent the prisoner to the shop to prepare for her a laudanum draught, with water for the menstruum. When the prisoner returned with it, the physician, in consequence of observing it to be muddy, was led to taste it, before he gave it to the sick lady: and finding it had the taste of corrosive sublimate, he preserved it, analyzed it, and discovered that it did contain that poison. The prisoner stated in defence, that he had a second time committed a mistake, and instead of water had accidentally used for the menstruum a corrosive-sublimate injection, which he had previously prepared for a sailor. This was proved to have been impossible; for the injection contained only five grains to the ounce, while the draught, which did not exceed one ounce, contained fourteen grains.[[129]]
I believe it must be allowed, that, as the medical inquiries preparatory to trial are commonly conducted without the inspector being made acquainted with the moral circumstances in detail, it is rarely possible for him to foresee what points should be attended to, with the view of illustrating the intent. But the case now related will show that it is impossible for him to render his inquiries too minute or comprehensive; and more particularly, it shows the propriety of ascertaining, whenever it is possible, not only the nature but likewise the quantity of the poison.