courts, in what particular form witnesses, called as experts, shall be interrogated upon the subjects in regard to which they are called to testify. In the case of King v. Higginson,30 which was a conviction for murder, the question of the form of the inquiry was submitted to all the judges in Westminster Hall, who returned for answer, that the witness cannot be asked his opinion upon all the evidence in the case, where he has been present during the whole trial: Whether the prisoner was conscious of doing wrong in the commission of the act, and whether he was at the time laboring under delusion? because this form of putting the inquiry, calls upon the witness to pass upon the truth of the testimony. And where the testimony is conflicting, it will not appear, in this general form of putting the inquiry, what portion of the testimony the witness assumes as true. And even where there is no conflict in the evidence, it was said by the judges, that this general form of putting the inquiry, could not be insisted upon, if objected to. if objected to. A similar rule has been adopted in some of the American states.31 30 1 Car. & K. 129. 1 Woodbury v. Obear, 7 Gray, 467,471. But in Negro Jerry v. Townshend, 9 Md. 145, it is said, a medical man who has been present during the whole trial, may be asked what his opinion would be, upon the hypothesis that all the testimony is true. In the case of the State v. Windsor, 5 Harring. 512, the court held the following a proper question to be put to a medical expert: You have heard all the evidence in the case, suppose the jury are satisfied of its truth, what is your opinion of the state of the prisoner's mind, at the time of the commission of the alleged crime? Was the prisoner, at the time of doing the act, under any, and what kind of insanity or delusion, and what would you expect wonld be the conduct of a person under such circumstances? But in The People v. M'Cann, 3 Parker's Cr. Rep. (N. Y.), 272, it was held not to be a proper inquiry to a medical expert present during the trial, what was his opinion, upon the facts stated, in regard to the sanity of the prisoner on the night of the homicide, but the witness was allowed to give his opinion upon a hypothetical case embracing the same facts, and that the minutes of testimony might be read to the witness, and his opinion asked, supposing that state of facts to have existed. And a medical expert may express his opinion upon certain facts detailed by other witnesses, or upon his personal observation. M'Allister v. The State, 17 Alabama, 434. 21. In this last case the court say, the question should be thus propounded: "If certain facts assumed by the question to be established by the evidence, should be found true by the jury, what would be his opinion, upon the facts thus found true, on the question of soundness of mind." In the case of the King v. Higginson, Mr. Justice Maule, who dissented from the other judges, shows very conclusively, that in England, until a very recent period, the general form of inquiry of professional witnesses, whether the person was, or not, of sound mind, had always been allowed, and that it was far the most natural and convenient mode of conducting the inquiry. Of this we think there can be no question, and that all the modern refinements upon the form of putting the inquiry to experts, has been attended with no practical results. But it is important that the course of practice should be, as nearly as possible, uniform, and that it should be reasonable, and attended with good practical results. 22. In an important case,32 Shaw, Ch. J., declares the form of inquiry to be, assuming the jury find the facts as testified by a certain witness, or by all the witnesses, when there is no conflict in the testimony, whether in the opinion of the witness the prisoner was insane; and what was the nature and character of the insanity indicated, if any; what state of mind such facts indicated; and what the witness would expect would be the conduct of such a person, under any given circumstances? Mr. Justice Curtis, adopted a similar rule in regard to the mode of putting the inquiry in such cases, in a case in the Circuit Court of the United States.33 The most convenient mode of putting the inquiry, and the least exceptionable one, in our judgment, is to inquire what state of mind is indicated by certain facts, assumed, or testified by certain witnesses, or in any other hypothetical form of bringing the point of inquiry to the mind of the * Commonwealth v. Rogers, 7 Met. 500. witness. If the witness says the facts assumed indicate mental unsoundness, he may be inquired of in regard to the state and degree of mental unsoundness thus indicated, and how far it will disqualify the person for business, or render him unconscious of the nature of his conduct. He should also be inquired of, whether these facts are explainable in any other mode except upon the theory of insanity, and with what degree of certainty they indicate the inference drawn by the witness.34 23. In McNaghten's Case, Lord Brougham said, in regard In Sills Brown, 9 Car. & P. 601, which was a case of collision at sea, nautical men were examined as experts, and were required to state what was the duty of the captain under certain assumed states of facts, which coincided with the theory of the different sides. And in Jameson v. Drinkald, 12 Moore, 148, Mr. Justice Parke said: That in such cases nautical men may be asked to what cause they think the accident attributable, but they must not state upon which side they consider the fault to be, this being the exclusive province of the jury. It seems to us this is being deluded by a pretty thin disguise, but after all there may be something in the distinction more than is obvious to mere common sense. A plain man would think, if the witness told, to what the accident was attributable, this must inform the jury, which party in his opinion was in fault. 10 Cl. & F. 210. This point is discussed by Dr. Ray, in the last edition of his valuable work, pp. 572 et seq., with great thoroughness and ability, and in a far more practical manner than is common with the legal profession. But we think he gives more weight to the judicial refinements upon the question, than they are fairly entitled to have. He shows very fully, what every one, at all conversant with trials, has had occasion often to observe, that the hypothetical mode of putting scientific inquiries to the experts, does not essentially differ from the straightforward, common sense mode of putting the question. And we think this should satisfy every one that the only importance in the matter is to have reasonable uniformity in practice. In the early case of Earl Ferrers, 19 Howell, 943, The Earl of Hardwicke said: "The question must be asked whether this or that is a symptom of lunacy." In Reg. v. Frances, 4 Cox, C. C. 57. Baron Alderson said: "The proper mode is to ask, what are the symptoms of insanity,' or to take particular facts, and assuming them to be true, to ask whether they indicate insanity." But in both these cases, the witnesses were not allowed to answer the direct question, whether 府 to the proper mode of interrogating the experts: "You shall ask them if such a fact is an indication of insanity, or notyou shall ask them upon their experience, what is an indication of insanity you shall draw from them what amount of symp toms constitute insanity." 24. Lord Campbell said, "the witness may give general scientific evidence, on the causes and symptoms of insanity, but he must not express an opinion as to the result of the evidence he had heard, with reference to the sanity or insanity of the prisoner." 25. The proper office of experts is to instruct the court and jury, in the laws of a particular science or subject, in order to enable them to judge of the force and application of the testimony, in the same understanding mode in which they would be able to do, if they had been before properly instructed upon the subjects involved. It is, so to speak, to educate the court and jury by a kind of short-hand process, in a particular department of science or art. 26. The witness may, therefore, no doubt be asked, in detail, his opinion upon each particular of the testimony given, and whether it indicates mental unsoundness, and whether it is explainable upon any other theory, and if so, what is the degree of probability that it results from the one cause or the other. He may also be asked, whether, if all the facts deposed do exist, it would be consistent with the theory and history of insanity, to call the man sane, or insane, as the case may be. And he may also be inquired of in regard to the particular species of insanity, which is indicated by the testimony, and as to the history and development of that species of insanity, and the degree of mental incapacity indicated by the symptoms testified to. In short, every question, tending to test the character and accuracy the prisoner was insane, since that was the only question to be submitted to the jury. And the same rule was adopted by Lord Campbell, in Doe d. v. Bainbrigge, 4 Cox, C. C. 451. . of the opinion of the expert, upon all the symptoms disclosed in the evidence, and which ought to have been, or might have been, expected to have been disclosed, by the alleged form of insanity, if it really existed. 27. So that the testimony of a medical expert, upon the question of insanity, and the rule must be the same in other cases, may be taken in regard to all the facts disclosed by the testimony, where the witness has attended during the whole trial, by referring him to the testimony, either in gross, or in detail, as coming from particular witnesses; and when he has not attended the trial, by repeating such facts to the witness (as a hypothetical case), as his opinion may be desired upon. There seems to be no restriction upon this course, even in the English practice, and it seems to us the more lucid, and the fairer course of examination, in regard to the subject. You may also, according to both the English and American practice, require of the experts any extent of instruction, in regard to the general subject of insanity, or other subject before the court, or the particular form of the disease under investigation, which the leisure of the court and jury will allow them to wait for. In this way it is supposed the jury will be enable to possess themselves of all the important matter contained in the approved treatises upon the question under consideration. 28. The question has sometimes been made, how far ordinary physicians are to be regarded as experts upon the general subject of insanity, since that malady has become strictly a specialty, in regard to treatment, throughout the country, where any distinction is attempted to be maintained between the mode of giving testimony by experts and other witnesses, as there is everywhere, in regard to expressing an opinion in relation to the facts contained in the testimony of other witnesses, or embraced in the general range of the subject, it seems very questionable how far all the medical profession can properly be regarded as experts upon this subject. If the capacity to give testimony as an expert, depends upon the practical experience of the witness, |