In an action by a principal against his agent to recover in part certain commissions alleged to have been erroneously paid, where, on an answer and counterclaim for the balance, the original action is dismissed, and the case is tried on the counterclaim, and the evidence of plaintiff shows that defendant, while his agent in the purchase of lands, unknown to him received a commission from the agent of the vendor, is a sufficient defense to the action on the counterclaim, and a demurrer to such evidence was improperly sustained. Plottner v. Chillian (Okla. Sup. '08), 95 P. 775.