It seems to us that this case was tried and submitted to the jury upon an issue of fact which was wholly immaterial, and that the real merits of the case in controversy between the parties were lost sight of and left untried.
To the claim of the plaintiff for the price of the cow, it was competent for the defendant to show, in reduction of damages, a breach of warranty of the animal, on the part of the plaintiff. Perley v. Balch, 23 Pick. 283. Evidence on this point was competent under the general issue. 1 Chit. Pl. (6th Am. ed.) 600. So far, the proceedings at the trial of the case were regular, and the parties confined themselves to what was properly at issue between them. But the evidence offered by the plaintiff, in answer to this defence, of an executory agreement between himself and the defendant to rescind the original contract for the purchase of the cow, upon certain terms which were never carried into effect, had no legitimate tendency to meet the defence relied on by the defendant, but was wholly irrelevant and foreign to the real subject of inquiry before the jury. It neither denied or in any way answered the averment of the defendant of a breach of warranty. It was not a reply of accord and satisfaction, release and discharge, or payment of the damages caused by such breach. It left the case, for all material purposes of the issue joined between the parties, exactly where it was left on the defendant’s evidence. Instead of relying on the contract for the purchase of the cow, and his right to recover thereon, and meeting the evidence offered by the defendant in reduction of the agreed price, the plaintiff set up an entirely new, separate, independent contract between the parties. That this new contract was not intended to abro *265gate the original contract, or to be a substitute for it, is shown by the fact that the plaintiff himself sues and claims to recover on the latter as still in force and binding on the defendant. If a new contract was made between the parties, with the terms of which the defendant failed to comply, and thereby caused damage to the plaintiff, he has a good cause of action therefor against the defendant; but it constituted no answer to his own breach of warranty in the original contract for the purchase of the cow. The plaintiff forsook his original case, and had recourse to another. He attempted to set up, as an answer to the proof of a breach by himself of the contract in suit, the breach of another separate and distinct contract by the defendant. In short, the evidence offered by the plaintiff, in reply to the defence set up to his claim, in no way explained, maintained, or fortified his original cause of action, or rebutted the evidence offered in support of the defence. It was, therefore, wholly irrelevant and immaterial, and failed to meet the case really in issue.
It appears by the exceptions, that the whole case was eventually submitted to the jury on the issue which grew out of this immaterial matter. This being so, it follows that the real merits of the case have not been determined by the verdict, and therefore there has been a mistrial. In such cases, a verdict does not help an immaterial issue, and it is the duty of the court, in order to effect substantial justice between the parties, to order a new trial. Verdict set aside.