able, with the assistance provided by our system of criminal procedure, to form an opinion upon the question whether a given result has been obtained by recognized scientific processes; or, whether the assertion of its validity depends upon propositions, the accuracy of which forms matter of bona-fide dispute amongst scientific men.

We must remember that the evidence upon these points which is submitted to jurors is given on oath, that it is given subject to the rules of evidence, that it is also given subject to cross-examination, and that a judge, whose life has been passed in acquiring and in exercising the faculties. requisite for the discharge of that function, points out to the jury what is the relevant and essential part of the evidence, and what part merely tends to raise immaterial issues. It is clear that with this assistance the jury may be perfectly able to arrive at a conclusion, free from all reasonable doubt, upon the questions submitted to them. And it must be observed, that the words "may be able” are of the essence of the question. The object of trial by jury is to obtain the highest amount of certainty, and this certainty is required, not merely for the satisfaction of the minds of the jurymen, but for the satisfaction of the public at large. The object is, that punishment should not be inflicted unless an amount of proof be given which has satisfied twelve ordinary men, and is enough to satisfy all ordinary men, that the prisoner really is guilty. Now that, in a great many cases which depend on scientific evidence, a jury may be satisfied, is true beyond all dispute whatever. No one ever thought of doubting that L'Angelier was poisoned by arsenic whoever gave it him, yet that conclusion rests upon scientific grounds, of the value of which not one person in ten thousand of those who hold it is able to judge. The only cases, therefore, in which there would be any occasion for a jury of experts-assuming for the moment that their opinion would be in itself more valuable than that of a jury of the ordinary constitutionwould be to warrant convictions in those very exceptional cases in which the evidence is of so refined a nature as to leave a substantial doubt on the minds of men of ordinary intelligence. Whether convictions, so obtained, would or

ought to give satisfaction to the public at large, is a very doubtful matter. It is hardly possible to imagine a case in which ordinary men would be perfectly sure, whilst experts would remain in doubt.

These grounds would be enough to justify a conclusion in favour of the present system, but my view goes further than this. I maintain that, even in extreme cases, ordinary men have the materials for forming a perfectly trustworthy judgment. Very few trials have attracted so much attention as the trial of Palmer for the murder of Cook, and probably none ever occurred in which such a profusion of conflicting scientific evidence was offered to a jury. If therefore, in such a case, a jury was a competent judge, it would be competent in any case whatever. The only question in that case which involved scientific considerations, was this-Did Cook die of poisoning by strychnine? Now, the evidence to show that he did was as follows:-The foundation of the whole was a confidence in the capacity of physicians to express an opinion as to the nature of certain symptoms, and to give an account of the character of known forms of disease. Next, it was proved by the common consent of every one who was entitled to speak on the subject, that the man died of tetanus; and it also appeared that, upon the most careful and elaborate inquiry, there were but three known forms of that diseasenamely, tetanus caused by wounds; tetanus originating spontaneously; and tetanus caused by strychnine. That the disease in this case was not caused by wounds was plain, inasmuch as there were no wounds to cause it. That it was not idiopathic, or spontaneous, appeared indefinitely probable -first, because the disease itself was almost unknown in this country; next, because the course of the symptoms was in several respects different; and lastly, because there was no existing cause to account for its appearance. On the other hand, the symptoms were stated upon oath by a number of physicians of the highest character and experience, to be precisely those which strychnine would produce. This, however, was not all; for thirteen scientific witnesses, called for the defence, who assigned five or six different diseases as the cause of the death, all agreed that the symptoms of those

diseases closely resembled those of strychnine; so much so, that one of them made an examination upon the body of a patient, who had died of the disease to which he referred Cook's death, to see whether he had not been poisoned. Here, therefore, was the strongest possible proof that the man actually had died of the administration of strychnine; and this, when added to the evidence of motive, of the unexplained possession of strychnine by Palmer, and of his administration to Cook of all the food he received in his last illness, was evidence upon which any man would have acted in weighty affairs of his own, and greater evidence than that it would be absurd to require.

It is indeed a weighty and important reflection that men actually have at times to judge, and that in matters of life and death, upon scientific evidence, without sitting on juries. A man observes a small swelling on his thigh. He goes to a surgeon, who says, "this is an aneurism, and if you do not allow me to cut down upon the artery and tie it, you may fall down dead at any moment." He shows it to another, who says, "it is no aneurism at all, but a mere tumour on which I will operate; if I do not, you will be exposed to some dreadful consequence or other; but if I am wrong, and it is an aneurism, as soon as I make the first cut you are a dead man." Here a man is judge of life and death in his own case, nor can he escape the necessity of deciding. He would, if a man of sense, be probably able to come to a pretty clear conclusion as to whether he should trust the first surgeon or the second, although he might know very little of surgery.

These illustrations lead to the third proposition laid down above, namely, that a jury composed as at present is more likely to arrive at a sound conclusion in such cases as I refer to, than either a jury of experts, or a jury bound by the decisions of experts.

I do not know that any one advocates the opinion that there is any class of cases which ought to be tried before a jury composed exclusively of experts, whether physicians in a poisoning case, engineers in a railway case, or professors of handwriting in a case of forgery. The proposition would be too extravagant to be maintained, but it is well worth while

to point out the reason of this extravagance. It is that in every case the circumstances are so much mixed up together, that it is quite impossible to say whether it belongs to one class or another, so that, unless a separate jury is to be empannelled for each division of the evidence, the whole matter must be left in the hands of some one body. Thus in Palmer's case, if a jury of physicians had been required by reason of the medical bearing of the case, a jury of chemists would have been wanted to estimate its chemical merits, a jury of sporting men to give a verdict as to the betting part of the business, and a jury of the ordinary composition to judge of the degree in which the different witnesses were actuated by partizanship, or by personal or professional animosity. Any attempt to introduce the principle of divided responsibility must lead towards this absurd result, and would infallibly strike a fatal blow at the weight of the verdicts of juries.

I am not able to speak with precision upon the practice of foreign countries in respect of scientific evidence; but I believe I am correct in saying, that, though in France the answers of experts are not binding on the court in theory, they are so in practice, in as much as no evidence of a scientific character is admitted except at the discretion of the court, which determines exclusively who shall, and who shall not, be allowed to give what are called "renseignements in such cases. It is obvious that the practical result of this is, that the jury are relieved from the responsibility of what may be called the scientific elements of their verdict. They are told, for example, "you must take it as matter of science that, whenever a man takes into his system strychnine enough to poison him, it will be discovered after his death in such and such organs."

Now, the objections to the adoption of any such system as this are threefold, and each of the three objections is conclusive. In the first place, that it would be found practically impossible to frame the question to be left to the experts in such a manner that the answer would be of the slightest use. Thus, in Palmer's case, the really material question was thisIs Dr. Taylor so good a chemist, that if he performed a certain specified operation on a certain specified part of the body of

John Parsons Cook, which part was taken from the body, under such and such circumstances, the fact that he discovered no strychnine in that substance would be evidence that none was present there? and if so, to what weight would that evidence be entitled? What expert could possibly answer such a question? Without great detail and specific reference to every circumstance of the case, the answer would be worthless. Great detail and specific reference to circumstances is exactly what we get already by cross-examination : without them, the official dicta of experts would be worthless, and with them, they would be superfluous.

Secondly, every argument which is urged to show that there is a conflict in medical and scientific opinion, proves that the dicta of experts cannot be taken as conclusive. Let us suppose for example that, in Palmer's case, it had been referred to Sir Benjamin Brodie, Dr. Todd, Mr. Curling, and Mr. Solly, to say what was the cause of Cook's death; and suppose they had found in accordance with the evidence which they gave in the witness box, that he died of strychnine, and that this finding had been taken as conclusive, to the exclusion of all other evidence, can any one say that the result would have commanded general approbation? It would have been universally objected to their finding, that other doctors would have found an entirely different verdict, and that there ought to be some one to decide between them. In other words, the common sentiment would have felt that they ought to be witnesses and not judges.

Thirdly, a tribunal of experts would hardly ever decide on evidence, but almost always on their own private opinion of the subject-matter to which the evidence applies. The guarantee most rightly demanded by the public in the infliction of punishment is, that convictions should be grounded on the application of well-established and well-recognised principles, and not on speculation. The question which juries decide is-Is this in accordance with the established opinion? The question which experts would attempt to decide would be-Is this true? and it is the former and not the latter question to which an answer is desired. This may appear at first somewhat paradoxical, but on further examination it will, I think,

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