Where an agent transacted all the business with reference to the collection of the principal and interest of debts secured by note and mortgage, and acted as the agent of the investor in the care and protection of the security and to deal with the security as the agent deemed best, with the full knowledge of the principal, payment of a note to such agent was payment to the principal. Pochin v. Knoebel, 63 Neb. 768, 89 N. W. 264. Compare Sec. 255, 352.