Where the broker knew that the principal held only a mortgagee's interest in the property, and might not be able to obtain title by foreclosure, the broker could not recover commissions for negotiations which were not completed because the principal did not obtain title through such proceedings. Corbin v. Mechanics' & Traders' Bank, 106 N. Y. S. 573, 121 App. Div. 744; Montgomery v. Amster (Tex. C. A. '09), 122 S. W. 307; Cain v. Min-norette, 162 N. W. 287, - Mich. Sup. -; Gettlum v. Lewis, 172 N. W. 387, - Mich. Sup. -; Brownell v. Hanson, 186 P. 873, - Wash. Sup. - .