59-5-2. Agent's responsibility as principal. One who assumes to act as an agent is responsible to third persons as a principal for his acts in the course of his agency, in any of the following cases, and in no others:
(1) When, with his consent, credit is given to him personally in a transaction;
(2) When he enters into a written contract in the name of his principal, without believing, in good faith, that he has authority to do so; or
(3) When his acts are wrongful in their nature.Source: CivC 1877, § 1377; CL 1887, § 4000; RCivC 1903, § 1696; RC 1919, § 1278; SDC 1939, § 3.0402.