Sec. 640d of the Code (Laws 1901, p. 302, c. 128), making the offering of real property for sale, without written authority from the agent or his attorney in fact, a misdemeanor, being unconstitutional, does not preclude a broker having no written authority from either party to the contract for an exchange of property from recovering commissions for procuring the execution of the contract. Trick v. McKenna, 101 N. Y. Sup. 317, 115 App. Div. 701.