One man may employ another to mow his lawn, but there are no relations here that inevitably seem to affect the rights of other parties. But when one man employs some one else to represent him in dealing with a third person, the relation of agency arises. It can only arise from contract, express or implied. The agent is not subject to the direct control of the principal. A employs B to purchase an automobile for him. B does so. A is the "principal" or employer; B is the "agent." The law of California defines an agent to be "one who represents another called the principal in dealings with third persons; such representation is called agency." Agents are of two classes: (1) "general" and (2) "special." A general agent is authorized to conduct all the business of the principal, or at least all the business of a particular kind. A special agent is authorized only to do one or more specific acts for his principal. Whatever business a person can transact himself he may transact through an agent. Of course, what he cannot do himself he cannot accomplish through another. The act of the agent is really the act of the principal.