In a suit upon several of a series of promissory notes,'some due and some not matured except under a stipulation that they should become due if any one of the series was not paid within thirty days after maturity, a verdict of a jury is necessary before a judgment can be rendered. A suit on notes not due except by virtue of such a stipulation is not “founded on unconditional contracts in writing,” within the meaning of paragraph 7 of section 4 of article 6 of the constitution of this State. This case is controlled by Rodgers v. Caldwell, 112 Ga. 635, and cases therein cited.

Judgment affirmed.