1. Upon the facts proved the plaintiff had a good cause of action against the firm. The injury was occasioned either by the negligence of servants employed by both defendants, or of one of them, while acting within the scope of the copartnership and transacting the business of the firm. Partners, like individuals, are responsible for the negligence of their servants while engaged in the business incident to their employment ; and if one partner acts, he is considered as the servant of the rest of the firm. Moreton v. Hardern, 4 B. & C. 223, and 6 D. & R. 275. Collyer on Part. §§ 457 & seq. Story on Part. § 166.

2. If the defendants had a right to rely on the fact that the bad habits of the plaintiff aggravated the consequences of the *193injury which he had sustained, in order to reduce the amount of damages, then the evidence of surgeons as to the effect of predisposing causes on similar injuries was clearly competent. If, on the other hand, a tortfeasor cannot avail himself of proof of the health or condition of the plaintiff at the time of the injury, for the purpose of diminishing the damages, then the evidence introduced by the plaintiff was irrelevant. And in either view its introduction worked no harm to the defendants.

Exceptions overruled.