Defendant agreed to pay plaintiff a commission for finding a purchaser with whom he could exchange his stock of goods for land, and the plaintiff secured a contract with P. to exchange a certain tract of land for defendant's stock of goods, but by a mistake of P., the land described in the contract was not owned by him; it did not appear that defendant was aware of the mistake. Held, that plaintiff was not entitled to a commission. Snyder v. Fidler, 135 Iowa 304, 112 N. W. 546; Hensel v. Witt, 134 Wis. 55, 113 N. W. 1093. See also Secs. 59, 476.