Plaintiff, a real estate broker, secured a customer to take defendant's premises in exchange for his own, and to pay defendant for the difference in the value of the equities; no time was stipulated as to when the exchange should take effect, and a tenant in defendant's premises refused to vacate without the statutory ninety days' notice, and defendant refused to perform unless the purchaser would take subject to the lease; this the latter refused to do, and the transaction was not consummated. Held, that since the plaintiff knew of the existence of the lease, he had not perfected a contract for exchange so as to be entitled to the commissions. Mainhart v. Paerschke, 65 N. Y. S. 494, 32 Misc. 97; Low v. Woodbury, 95 N. Y. S. 336, 107 App. Div. 298. See Sec. 33.