Facts or opinions on the subject of insanity, as on any other subject, cannot be laid before the jury except by the testimony under oath of persons skilled in such matters. Whether stated in the language of the court or of the counsel in a former case, or cited from the works of legal or medical writers, they are still statements of fact, and must be proved on oath. The opinion of a lawyer on such a question of fact is entitled to no more weight than that of any other person, not an expert. The principles governing the admissibility of such evidence have been fully considered by this court since the tria *339of Rogers; and the more recent English authorities are against the admission of such evidence. See Collier v. Simpson, 5 Car. & P. 74; Cocks v. Purday, 2 Car. & Kirw. 270; 1 Greenl. Ev. § 440, note.
James G. Fuller, formerly chairman of the board of inspectors of the state prison, called as a witness for the defence, testified to having had certain interviews with the defendant before the homicide, and to his appearance and conversation at those interviews. The defendant’s counsel then proposed to ask the witness what opinion of the prisoner’s mental condition he formed at the time of those conversations.
J. H. Clifford, (Attorney General,) objected. E. Merwin, for the defendant, contended that any witness might state facts occurring within his own knowledge, and the impression made on him at the time by those facts; and cited De Wilt v. Barley, 13 Barb. 550; Hathorne v. King, 8 Mass. 371.
Shaw, C. J.Subscribing witnesses to a will, being the witnesses chosen by the testator, are allowed to state their opinion as to his sanity. But other witnesses, not experts, are not permitted to state then: opinion, even if they first state the facts and circumstances on which it is founded. This distinction has been long established in this commonwealth, and uniformly adhered to. See Poole v. Richardson, 3 Mass. 330; Needham, v. Ide, 5 Pick. 510.
John B. Rice, one of the prisoners in the state prison, called as a witness by the Commonwealth, testified to quarrels between the defendant and Adams some time before the homicide, and was asked by the attorney general whether he had ever heard Adams express any hostile feelings towards the defendant.
Merwin objected that such declarations of Adams were inadmissible, unless shown to have been made in the defendant’s presence, or to have come to his knowledge.
Shaw, C. J.The theory of the defence being that there was no ground for the defendant’s belief of Adams’s hostility towards him, tb" ^Harations of Adams are admissible to show his state *340of mind towards the defendant at that time, and as thus tending to show some real ground for the defendant’s feelings towards Adams.
John Goodcourage, also a prisoner, called as a witness for the Commonwealth, testified to certain facts tending to show that the homicide was premeditated by the defendant; and was asked, on cross examination, when he was first inquired of by any one, concerning the facts to which he had testified in chief; to which he answered, “ about six weeks before.” On reexamination the attorney general asked him whether he had communicated the same facts to other persons at or about the time of the homicide. Merwin objected that the question could not be put for the purpose of strengthening the testimony of the witness, and referred to Deshon v. Merchants Ins. Co. 11 Met. 199, 209.
Shaw, C. J.'The rule excluding such testimony is confined to the examination in chief, and does not apply to a case whejo the other party has sought to impeach the witness on crosu examination. The purpose of the cross examination in this particular having been to impeach the witness, the question may be put.
Verdict, guilty.