A person employed by a merchant, or in a mercantile establishment, as a salesman, book-keeper, accountant, amanuensis, etc., invested with more or less authority in the administration of some branch or department of the business, while the principal himself superintends the whole. State v. Barter, 58 N. II. 004; Ilamuel v. State, 5 Mo. 264; Railroad Co. v. Trust Co., 82 Md. 535, 34 Atl. 778, 38 L. R. A. 97.