(1) Where duality of real estate agency is relied on as a defense to an agent's action, defendant must prove not only the duality of the agency, but that same was not known to both parties. Bellew v. Ware & Harper, 84 S. E. 597, 10 Ga. App. 149.

(2) In an action to recover commissions by one who has been employed as an agent to effect certain resales, a defense which consists of a charge that such agent had made certain secret unlawful profits, in connection with his employment, calculated to defeat a recovery, must be established by a preponderance of the evidence. Windsor v. Kelley Coal Co., 147 I11. App. 451.