Evidence, Opinion: experts. The rule, that a witness not an expert may be allowed to state a conclusion of fact at the time of his observation in regard to matters which are capable of being understood by men in general and which cannot be reproduced before the jury as they appeared to the witness, does not make admissible the conclusion of a witness as to the kind of fire that would produce the conditions that he observed when he examined a certain building.
At the trial of an indictment for wilfully and maliciously burning a building occupied in part by the defendant, an expert in the investigation of fires should not be allowed to testify to his opinion as to the kind of fire that would char an ordinary mop-board, sheathing and partition and burn holes in an ordinary wooden floor without any charring or burning between the different surfaces, this being a matter of ordinary experience or knowledge such as men in general understand and comprehend.
LORING, J.
The testimony of the witness as to the conclusions drawn by him from what he saw was not admissible as the conclusions made by an ordinary witness from observation of things which cannot be reproduced and therefore although involving opinion admitted ex necessitate, as to which see Commonwealth v. Sturtivant, 117 Mass. 122, 133; Beverley v. Boston Elevated Railway, 194 Mass. 450; Partelow v. Newton Boston Street Railway, 196 Mass. 24; Jenkins v. Weston, 200 Mass. 488.
Doubtless there are cases where the effect of some kinds of fire upon some kinds of material substance is not a matter of ordinary experience or knowledge such as men in general understand and comprehend. But the kind of fire or fires which char ordinary mop-boards, sheathing and partitions and burn holes through an ordinary wooden floor without any charring or burning between is not one of them. See in this connection State v. Watson, 65 Maine, 74; Wood v. Chicago, Milwaukee St. Paul Railway, 40 Wis. 582; Higgins v. Dewey, 107 Mass. 494; Lyman v. State Mutual Fire Ins. Co. 14 Allen, 329; Fireman's Ins. Co. v. J.H. Mohlman Co. 33 C.C.A. 347; 91 Fed. Rep. 85.
The entry must be
Exceptions sustained.