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doubt guilty), she acquired so much useful knowledge from the evidence of the medical witnesses during the trial relating to the properties and mode of administering of arsenic, that on her liberation she renewed her practice with her fresh information, which, nevertheless, did not avail her altogether, for she was eventually caught, tried, and hanged, as an Essex arsenic poisoner.
With respect to a fallacy often repeated in courts of justice, Dr. Taylor makes some useful remarks. He observes, “that the quantity remaining in the stomach, or the portion of absorbed poison deposited in the tissues, can give no idea of the quantity actually taken by the deceased ; since more or less of the poison may have been removed by violent vomiting and purging, as well as by elimination. But the quantity found free in the stomach and bowels, even after a portion has been thus lost, is often more than sufficient to destroy the life of a human being. It is singular that, notwithstanding the existence of these very obvious and natural causes for the removal of a poison from the stomach, barristers should so frequently address the inquiry to a medical witness, whether the quantity of poison found in the body was sufficient to cause death? Whether this question be answered in the affirmative or negative, is a matter which, medically speaking, cannot at all affect the case ; since either no traces of poison, or but a very small portion, may be found in the viscera, and yet the deceased may have assuredly died from its effects. Absorbeu arsenic, as it exists in the tissues, is never found except in very minute proportion, a proportion commonly insufficient to destroy the life of another. Hence, whether much or little be detected, the object of this question is not very apparent; since the fact of death having been caused by poison does not, in the least degree, depend upon the precise quantity which happens to remain in a dead body. It has been truly remarked by Orfila, in regard to arsenic, and it equally applies to all poisons, that that portion which is found in the stomach is not that wbich has caused death, but the surplus of the quantity which has already produced fatal effects by its absorption into the system. The inquiry should therefore be directed to the probable quantity of poison taken, not to how
much remains in the body. This question is one of more importance than may at first sight appear. There is scarcely a trial for criminal poisoning in which it is not put to a medical witness, either by the judge or the counsel, for the prosecution or defenceSupposing poison to be found in the stomach, but not in sufficient quantity to destroy life, is it therefore to be assumed that the person did not die from its effects ? This would be equal to laying down the doctrine, in face of the most indisputable evidence to the contrary—that poisons, when taken into the body, are never liable to be expelled by vomiting or purging, or to be removed from the stomach by absorption, and carried out of the body by elimination. The real object of a toxicologist is to discover the poison by clear and undoubted evidence. If more than sufficient to cause death be found in a dead body, then the dose must have been larger than was necessary; but if this proof be always required, what is to become of those cases of criminal poisoning in which the prisoner administers a dose only just sufficient to destroy life; or in which the deceased, by the strengtlı of his constitution, happens to survive the effects for some days or weeks, and ultimately dies of exhaustion ? No poison would be detected under these circumstances. Orfila has most completely demonstrated the fallacy of this oljection to medical evidence, and the danger of a court of law relying upon it.
“ As an illustration of the kind of cross-examination which a medical witness must be prepared to undergo on this question, I subjoin an extract from the report of the trial of Reg. v. Palmer (May, 1856). Serjeant Shee, in directing his questions to me, thus deals with the matter :
"Q. Have you not told me to-day that the quantity of antimony that you found in Cook's body was not sufficient to account for death ? A. Perfectly so; but what was found in Cook's body was not all that he took. If a man takes antimony Q. Do you wish to add to your testimony? A. I do; because I see it is only a little misunderstanding. If a man takes antimony it produces these effects :-first, he vomits, by which some passes out of the body; some may escape by the bowels; there is a
great deal that passes off at once by absorption, and is carried out with the urine. I find by the experiments of Orfila, upon whom we are all inclined to rely, that in from four to seventeen hours antimony is found passing out by the urine. Q. Do you mean on your oath to say, from such traces of antimony as you found in Cook's body, you were justified in stating that your opinion was, that his death may have been caused by antimony? A. Positively and decidedly so; the amount found in his dead body affords not the slightest criterion of what he may have Śwallowed while living. I have sometimes found in a body less arsenic than would account for death. Q. But, if the amount found is not the slightest criterion of what may have been administered, how does that justify you, as an analytical chemist, in stating your opinion that so small a quantity may have caused death? A. I have not said what quantity may have caused death. I have said a certain quantity was found in his body, which may have been the residue of what had caused death.'
“The fallacies connected with this line of examination must be apparent. In no death from antimony yet recorded, has such a quantity of this substance been found in a body as would su fice to kill another person! When given in divided dosesas the evidence proved that it had been given in the case of Cook -and there has been violent vomiting in the intervals, it is not probable that small doses would accumulate and remain in the stomach and intestines for a week. Such questions, therefore, were only calculated to conceal the truth and mislead the jury.
“ The fallacy based on this inquiry is not confined to lawyers. Some medical men, even of good professional standing, have paid so little attention to the subject of toxicology that if the quantity of poison remaining in a dead body were less than that which is usually described as a fatal dose, they would be prepared to say that death was not caused by poison. They expect either that the whole dose swallowed should remain in the body as evidence against the administrator, or that vomiting, purging, and absorption are so nicely adjusted, that, to meet their theory, these functions are wholly arrested when the quantity is reduced to a
minimum fatal dose. The half grain of antimony found in the body of Cook might, however, be taken to represent the residue (at the time of death) of ten, twenty, or one hundred grains of tartar emetic taken during life! In spite of this obvious inference, Serjeant Shee was allowed on this occasion to mystify the facts, and to place the matter before the jury as if the half grain found in the dead body was the whole quantity of antimony that deceased could have taken; and, as this residue did not amount to a fatal dose for another person, it was insufficient to account for the deceased's death! Some of his medical advisers appear to have adopted the same view, since they represented it as a question whether half a grain of antimony could or could not account for the death of the deceased. Either ignorantly or designedly, they entirely overlooked the fact that there had been severe vomiting at intervals some days before death, and that such vomiting could not take place without the expulsion and loss of a portion of the substance taken” (Pp. 196-8).
An excellent illustration of the important functions which an expert has to perform when civil rights of parties are concerned, is afforded in the case of Stephens v. Barwell, which was tried at Wells in the autumn of 1855. The plaintiff complained that the fumes of lead escaping from the chimney of the defendant's works had been deposited on the plaintiff's land, whereby his cattle feeding on its herbage were poisoned. Now, it was admitted that some of the animals had died of lead poison. And the question arose, whether the plaintiff's chimney theory was the right one, or whether the poison was derived from another cause. Various circumstances suggested to the acute minds of Mr. Brand and Dr. Taylor, the improbability of the fumes of the chimney being the source of the mischief complained of. Other fields at different and long distances had also bad reputations for cattle being occasionally “moindered ;” and, before the defendant's lead-works were erected, it was ascertained that animals had been poisoned in the neighbourhood of the unwholesome fields. Points connected with the locality, and other matter, struck also the observant faculties of the two VOL. VII. NO. XIII.
scientific gentlemen, that the lead which poisoned the cattle came from some quarter. If it was not deposited by the fumes, could it be taken up by the tissues of the plant? The experts proceeded to examine the facts carefully. They found no lead on the outside of the herbage. A quantity of the grass
and shrubs was then dried and burnt, and lead was found in the ashes; and further, the soil was discovered to consist of disentegrated slag of ancient lead-works, and the sediment of the pond water contained silicate of lead and arsenic. The water was free from poison, but the sediment stirred up by the cattle when drinking was impregnated with poison. Soil from the plaintiff's fields was brought up to London, and mustard and cress was sown on this Mendip lead earth and also on common garden mould ; lead was found in that grown on the former, and none in the latter. So far for the means adopted by the scientific men acting for the plaintiff. The following paragraph relating to the evidence prepared by the defendant cannot be read without pain :—“As a proof that white lead from the flue was deposited on the surrounding vegetables, a branch of a tree was produced in court, the whole surface of which presented numerous white spots or stains, such as might have resulted from dipping it into the washings of white lead in water. That this had been the mode in which the stains were produced was rendered highly probable, among other matters, by the curious fact, that the cut surface of the branch presented in the fresh wood similar white stains! This branch was very judiciously not produced in the evidence, although brought into court apparently for that purpose.” The author sums up the result of the trial as follows :“This case shows that a charge of poisoning cattle may be plausibly made, and even apparently, sustained, by pseudoscientific evidence, when a proper examination of the facts may lead to the conclusion that the charge is wholly unfounded or unproved. As an 'expert,' and well acquainted with this locality, Mr. Herapath might have analysed the soil of the fields, and have tested by experiment the question—Whether growing plants would or would not imbibe lead from the earth ? instead of