The only question presented by this appeal is whether thei’e was error in the judge’s charge as to the burden of proof on the second issue.

The plaintiff having brought his action to recover a certain amount alleged to be due as the balance of the purchase price of land, the defendant answered admitting the agreement to purchase, and the amount agreed to be paid, and pleaded payment in full as a defense.

There was no controversy as to the agreement, nor as to the amount agreed to be paid, and the court properly instructed the jury to answer the first issue in the affirmative.

While the second issue: “Did the defendant commit a breach of said contract?” is in the form usually employed in actions to recover for breach of contract, when the burden is on the plaintiff to prove both contract and breach, the heart of the controversy here, and the only question being litigated was whether defendant had paid the amount he admitted he had agreed to pay. Regardless of the form of the issue, whether negative or affirmative, in substance, the issue raised was that of payment or nonpayment, and the form of the issue could not change the rule that the burden is on him who pleads payment.

In Furst v. Taylor, 204 N. C., 603, Mr. Justice Clarkson succinctly states the rule: “It is well settled that the plea of payment is an affirmative one and the burden of showing payment is on the one who relies on same. The burden of proof is a substantial right.” Collins v. Vandiford, 196 N. C., 237; Swan v. Carawan, 168 N. C., 472; Vaughan v. Lewellyn, 94 N. C., 472.

“It is a fundamental rule of evidence that the burden is on the party who asserts the affirmative of the issue.” Stein v. Levins, 205 N. C., 302.

Defendant’s admission of the agreement to pay a certain amount, nothing else appearing, would have entitled the plaintiff to judgment on the pleadings. Stein v. Levins, supra; McCaskill v. Walker, 147 N. C., *275 195. In avoidance, defendant alleged and offered evidence that he had paid the amount in full. “The burden of proof rests upon the party who, either as plaintiff or defendant, affirmatively alleges facts necessary to enable him to prevail in the cause.” Speas v. Bank, 188 N. C., 524-529.

The learned judge who tried the case below failed to properly instruct the jury that the burden of proof of payment was on the defendant, and for this there must be a

New trial.