Where one sued upon promissory notes relies, for his defense, upon a failure of the consideration, and the evidence shows that the failure of consideration has not been total, he must, in-order to au- - thorize any diminution of the plaintiff’s recovery, introduce evidence showing the extent of the failure. Merely to prove that there has ' been a partial failure of consideration, without giving the jury any facts from-which they could calculate the extent, of the failure, is not sufficient. Where the defendant in such a case fails to make out his defense, it is permissible for the court to direct a verdict in favor of the plaintiff. Judgment affirmed.