Burnett, J.,

delivered the opinion of the Court—Terry, J., concurring.

This was an action brought by plaintiff to recover damages occasioned by the negligence of the defendants in failing to keep a certain wharf in proper condition; in consequence of which alleged negligence, plaintiff states that certain property of his, namely, a horse and harness, were destroyed. On the trial, the plaintiff introduced his servant, who was driving the horse at the time of the accident, as a witness. The defendants objected to the witness as being incompetent, upon the ground of interest in the event of the suit. The objection was overruled, and the defendants excepted.

In was decided by this Court, in the case of May v. Hanson, July Term, 1855, “that it is not incumbent on the plaintiff to prove the exercise by him of ordinary care to avoid the injury, but the proof of want of it upon the part of the plaintiff, lies on the defendant; that he who avers a fact in excuse of his own misfeasance, must prove it.” (Beaty v. Gilmore, 16 Penn., 463.) In the present case, the answer sets up the negligence of the plaintiff or his servant, as the cause of the accident; and the act of the servant in the management of the horse, becomes the sub*256jeet of inquiry at the trial, and the right of the plaintiff to recover, may be defeated by the defendants showing that the negligence of plaintiff’s servant was the cause of the injury.

That the witness was interested in the event of the suit, so as to exclude his testimony, would seem to be clear from the provisions of the three hundred and ninety-third section of the Practice Act, and the authorities referred to in Greenleaf on Evidence, § 396. If the plaintiff recovered a judgment against the defendants, he could not thereafter recover against the witness for the same injury. The defendants having alleged negligence on the part of the plaintiff, and the plaintiff having charged the same on the part of defendants, and the Court having found these issues against the defendants, the judgment would have been conclusive as between the parties, and the plaintiff could never question them in any subsequent suit. And more especially after payment of the judgment by defendants, the witness could not have been sued for the same cause of action. “ Thus, in an action for an injury to the plaintiff’s cart or coach, or horses, by negligently driving against them, the plaintiff’s own driver or coachman is not a competent witness for him, without a release.” (Greenleaf’s Evidence, § 396.) And there is, in principle, no difference between the case where the master is plaintiff and where he is defendant, as the conduct of the servant is equally called in question in both cases. The negligence of the servant in either case defeats the master. In the case of Bailey v. Shaw, 4 Foster’s B., 299, referred to by the counsel of plaintiff, the Court held, that “ when the claim of the plaintiff or the defense rests upon any misconduct or failure of duty of the agent towards his employer, for which the latter would be answerable over to third persons, and the agent would be responsible to him, the evidence of the servant or agent is inadmissible in favor of his employer to support such claim or defence without a release.” And there can be no difference in principle between the case where the master is responsible over to third parties, and where he is only liable to the loss of property. In the case of Moble and Palmer v. Paddock, 19 Wendell, 456, Chief Justice Uelson says, “Therefore, when the action involves a breach of duty on the part of the agent, or servant, he cannot be called to disprove it, because, if the fact should be established, he would be liable over.”

The question asked the witness was a leading one, and should have been overruled. The instruction of the Court, though erroneous, may or may not have mislead the jury. As the case must be reversed on the other grounds, it is unnecessary to decide as to the injury done by giving the instruction alluded to.

Judgment reversed, and cause remanded.