1. An action may be brought and sustained on open account for goods sold or services rendered, although there may have been a special contract in writing governing the subject-matter of the suit, where it appears that the plaintiff has fully performed his part of the agreement and nothing remains to be done except for the other party to make payment. Tumlin v. Bass Furnace Co., 93 Ga. 594 (2, 3) (20 S. E. 44); Burch v. Harrell, 93 Ga. 719 (20 S. E. 212); Southern Printers Supply Co. v. Felker, 125 Ga. 148 (54 S. E. 193); Shedd v. Standard Sewing Machine Co., 21 Ga. App. 373, 376 (94 S. E. 646). In such a suit, the contract not being declared on, its breach does not constitute the cause of action, but the contract can be used merely as evidence of the indebtedness. Chapman v. Conwell, 1 Ga. App. 212 (2) (58 S. E. 137); Pittman v. Hodges, 13 Ga. App. 25, 26 (78 S. E. 688); Ittner v. Farmers State Bank, 15 Ga. App. 235 (82 S. E. 909).

2. Under the system of pleading in this State, there was nothing to prevent the plaintiff from embracing in his petition a separate and independent count based upon a breach of contract. (Southern Ry. Co. v. Chambers, 126 Ga. 404 (5), 410 (55 S. E. 37); McMillan v. Heard National Bank, 19 Ga. App. 148, 151 (91 S. E. 235).

3. The petition as amended was not subject to demurrer.

Judgment affirmed.