1. The amendment to the hill of exceptions is allowed,' and the motion to dismiss the writ of error is denied.
2. Where the defense to a suit is based solely upon a partial failure of consideration, before a verdict can legally be rendered giving the defendant the benefit of such partial failure it is. incumbent upon the defendant to show the extent to which the consideration failed. The jury must have sufficient data, presented by the evidence, upon which to base a verdict in such a case. Grier v. Enterprise Stone Co., 126 Ga. 17 (54 S. E. 806); Spence Drug Co. v. American Soda Fountain Co., 11 Ga. App. 473, 477 (75 S. E. 817). • Under application of this ruling to the facts of the instant case, the trial court erred in overruling the motion for a new trial, and the judge of the superior court did not err in sustaining the certiorari and in ordering a new trial.
Judgment affirmed.
Bloodworth and Harwell, JJ., concur.