The referee found in favor of the plaintiff, upon the only material question of fact controverted upon the trial. That question was, whether the defendant agreed to purchase the lands in question of Van Rensselaer, as agent of and for the plaintiff, and received money from the plaintiff for that purpose, as claimed by the plaintiff, or whether the defendant himself agreed to sell such lands to the defendant for fifteen dollars per acre, and procure from Van Rensselaer a deed or contract for the same to the plaintiff for that price, as claimed by the defendant. The testimony upon this question was conflicting, and the conclusion of the referee thereon cannot be disturbed by this court. The legal conclusion drawn by the referee from the facts found was correct. If the defendant agreed to purchase the land .as agent for the plaintiff, the former was bound to refund to the latter all the *422money he had received, except what he actually paid upon the purchase ■ of the land. An agent is bound to exert his care and skill in making as good a bargain' as practicable for his principal, and catinot retain for himself any of the profits or advantages of a contract made by him, without the consent of the principal, given with a full knowledge of all the facts. (Dunlap’s Paley’s Agency, p. 32, following Moore v. Moore, 1 Seld. 256.) The judgment of the Supreme Court affirming the judgment of the referee was right, unless the referee erred in receiving or rejecting evidence, having a bearing upon the question of fact litigated by the parties. There was no dispute upon the trial as to the price paid by the defendant to Van Rensselaer for the land; that was ten dollars per acre. The plaintiff was permitted to prove by a witness, that the defendant told her he paid fifteen dollars an acre therefor. This evidence was wholly immaterial upon any of the direct issues of fact litigated by the parties, and although erroneously admitted, could not have worked any injury to the defendant, and would therefore furnish no ground for the reversal of the judgment. But the defendant was introduced as a witness in his own behalf, and gave material evidence in his own favor, which, if fully credited by the referee, must have induced a report in his favor upon the questions of fact. His credibility, thus became- a material issue, and any evidence erroneously received, tending to impair it, furnished ground for a valid exception. The evidence received in this case, did tend to destroy the credibility of the defendant as a witness. It tended to prove that he had told a falsehood as to the price paid for the land. This may have induced the referee to.discredit his testimony; as it appears from the report, he actually did discredit it. The evidence was not introduced to contradict any testimony given by the defendant upon the trial, as he had given no evidence in conflict with it. Its only possible effect was to prove that the defendant had told a falsehood to the witness as to the price paid by him for the land, there being no dispute upon the trial or issue upon the pleadings upon that question. The evidence was clearly incompetent, and we *423have seen, that it may have produced injury to the defendant. The legal rule is, that where incompetent evidence is received, to which the proper exception is taken, the judgment must be reversed, unless it appears from the case that such evidence could not have injured the party. (Worrall v. Parmelee, 1 Comst. 519.)
Applying this rule, the judgment must be reversed and a new trial ordered, costs to abide event