The pathological and anatomical facts were, however, in themselves, so striking and satisfactory, that not the slightest doubt can exist as to the cause of the sufferings and death of the deceased; while, as Mr. Murray very justly states, the high probability, arising from the separate symptoms of each individual, is strengthened almost to certainty, by the simultaneous occurrence of these in a whole family of four persons; while no similar disease, indeed no epidemic of any kind, prevailed at that time.
We have only to add that the brother-in-law of this family was, in October, 1821, tried before the Judiciary Court at Aberdeen, for administering poison to his four relations; when the testimony given by the medical witnesses induced the judge and jury to consider the abstract act of poisoning proved. The accused afterwards confessed his guilt, and that he perpetrated the crime by means of Arsenic, put among the salt on the sunday morning on which the family were taken ill.
The public, and the profession, are greatly indebted to Mr. Alexander Murray for the details of this instructive case; and the patient attention and judgment with which he conducted the investigation, deserve the highest commendation, and afford an example which we sincerely hope future practitioners will endeavour to follow.
Q. V. What degree of information can be derived from administering the contents of the stomach of a person supposed to have been poisoned, to dogs, or other animals?
It has from time immemorial been generally believed, that no proof of poisoning is more satisfactory than that which is furnished by the effects produced upon dogs, by their swallowing the contents of the stomach of persons who are supposed to have died from poison. Writers on Forensic medicine have, however, adduced several objections to the validity of such a test; some of which are undoubtedly worthy of consideration, while others are the deductions of a theory which receives no support from experience. In the first place it has been stated, that substances poisonous to man, will not always occasion deleterious effects upon animals[[204]]; this, to a certain extent, is undoubtedly true; some of the Ruminantia appear to be less sensible to the operation of narcotic plants, than carnivorous animals. Aloes are injurious to dogs and foxes. Oxen are said to eat the Philandria Palustris, which is pernicious to horses; but we are very much inclined to believe that a poison sufficiently powerful to destroy the life of a man, would if administered in the same state of concentration, destroy that also of an inferior animal. It is in smaller doses only that the difference in the action of such bodies upon various animals becomes evident and appreciable. This opinion is confirmed by numerous experiments. Mr. John Hunter, in his evidence[[205]] on the trial of Donellan, in answer to the question, whether any certain conclusion can be drawn respecting the poisonous operation of a substance upon man, from its effects upon an animal of the brute creation, replied, “As far as my experience goes, which is not a very confined one, because I have poisoned some thousands of animals, they are very nearly the same; opium, for instance, will poison a dog similar to a man; arsenic will have very near the same effect upon a dog, as it would have, I take it for granted, upon a man; I know something of the effects of them, and I believe their operations will be nearly similar.” If any farther confirmation of this opinion were required, how extensively and satisfactorily has it been afforded by the late experiments of M. Orfila.[[206]] Mr. Hunter also, on the memorable trial above mentioned, explained a source of fallacy which attends such experiments upon animals; he is asked “whether there are not many things which kill animals almost instantaneously, that will have no detrimental or noxious effect upon a human subject, such, for instance, as spirits?” He replies that a great deal depends upon the manner of conducting the experiment, and that by forcing an animal to drink, the liquor often passes into the lungs. See Appendix, p. 272. Orfila, in his valuable work on poisons, instituted a series of experiments upon this subject, with the intention of determining the value of an experiment so generally accredited; from which he is led to conclude, 1st. That the practitioner should never attempt by force to make an animal swallow the suspected substance, nor should he put it into his food; for by such a proceeding he would not only run the hazard of losing the greatest part of it, because the animal would reject it, but the food with which it is combined might exert upon it some chemical action, or so envelope it as to protect the coats of the stomach from its contact; besides which it would, says he, happen, at least six times in ten, that a part of it would flow through the larynx into the lungs, and the animal will die of Asphyxia. 2d. The best method that can be employed, consists in detaching the œsophagus, perforating it with a small hole, introducing into it a glass funnel, and pouring the liquid into the stomach; that being done, the œsophagus is to be tied below the opening. It would, observes M. Orfila, be imprudent to prefer to this method, the use of an elastic gum tube adapted to a syringe, for many bite the tube, pierce it with holes, and the fluid then flows out of the mouth; besides which, syringes of tin might decompose certain poisonous fluids. The obvious objection to such a mode of administration is anticipated by this laborious experimenter with much ingenuity. It may be asserted, says he, that the animal perished from the operation of tying the œsophagus, and not from the action of the poison thus introduced into the stomach, but such an objection has no foundation in truth, for either the suspected substance is in quantity sufficient to destroy the animal, or it is not; in the first case death will take place during the first forty-eight hours, and will be preceded by symptoms more or less severe, a phenomenon never observed in the simple ligature of the œsophagus; in the second case, the experiment will not be more conclusive, than if the œsophagus had not been tied: and the author asserts, that the operation of tying the œsophagus would not, of itself, produce during the first forty-eight hours any other symptom than a slight dejection, and that consequently all other morbid phenomena that may be observed, upon such trials, ought to be attributed to the poisonous substance. To all this we reply, that we believe, in the hands of Orfila who has made a thousand experiments, that such results may be satisfactory, but we feel no hesitation in declaring, that we should not place the smallest reliance upon such an experiment when conducted by a person unaccustomed to the operations of experimental physiology. If there be no other mode of employing an animal as a test for poison, but by tying his œsophagus, we must, in a judicial point of view, reject it altogether.
But there still remains another source of fallacy connected with these experiments, to which considerable importance has been attached. It has been said that the acrid humours ejected from the stomach of a person labouring under a spontaneous disease, may kill an animal. Morgagni[[207]] relates a very remarkable instance, in illustration of this fact. A child having died of a fever was opened, when a quantity of green bile was found in the stomach, which changed the colour of the scalpel to violet; having dipped the point of the knife into this bile, two pigeons were wounded with it, and they soon died in convulsions. The bile was then mixed with some bread, and given to a cock, which also died in the same manner. From this general view of the subject before us, the forensic physician will be enabled to appreciate its just value, and to apply the indications it may furnish, in each particular case, without the risk of error. In some instances such experiments may prove nothing, in others they may afford only equivocal results, but which may add something to the general weight of circumstantial evidence; while others, again, may furnish proofs so unquestionable, as to leave no doubt upon the subject; such was the case in the instance of Michael Whiting[[208]], who was convicted of administering corrosive sublimate to his brothers-in-law, when it appeared in evidence that a portion of the poisoned dumpling was given to a sow, who in consequence became sick, and remained ill for several days.
We have now disposed of the several questions connected with the subject of poisoning, which must be regarded, in their forensic relations, as being of the highest importance. In considering the subjects, generally, there must necessarily remain doubts, many of which will be considerably diminished, or entirely removed, upon their application to particular cases; still, however, the nature of medical evidence upon such occasions must be frequently regarded as only sustaining high probabilities, and the professional witness may exclaim with Hoffman[[209]] “Ardua sane provincia ei imponitur cui determinandæ ejusmodi quæstiones exhibentur.”
ON THE CLASSIFICATION OF POISONS.
Poisonous substances have been very differently arranged by different authors, each appearing to have adopted a classification best suited to promote the particular views and objects of his own pursuit; thus, the botanist and chemist, engaged in the examination of the physical characters by which poisons may be individually distinguished and identified, have very judiciously erected their system upon the basis of natural history. The pathologist, whose leading object is the investigation of the morbid effects which follow the administration of these agents, with equal propriety and justice prefers a classification deduced from a generalization of the symptoms they are found to occasion; while the physiologist, who seeks to ascertain through what organs, and by what mechanism they destroy life, may be reasonably expected to arrange the different poisons under divisions corresponding with the results of so interesting an inquiry.
To meet the comprehensive views of the forensic toxicologist, an arrangement would seem to be required, that should at once embrace the several objects which we have just enumerated; for the data from which the proof of poisoning is to be inferred, are, as we have often stated, highly complicated in their relations. No such classification, however, can be accomplished, and we are therefore compelled to select one which may approach the nearest to our imaginary fabric. That which was proposed by Fodéré,[[210]] and adopted, with some trivial alteration in the order of succession of the classes, by Orfila, in his celebrated system of toxicology, although it has many defects and some errors, nevertheless merits the preference of the forensic physician; its basis is strictly pathological, and yet it distributes the different poisons, with some few and unimportant exceptions, in an order corresponding with that of their natural history.