The authority is created either by deed, by simple writing, by parol, or by mere employment, according to the capacity of the parties, or the nature of the act to be done. It is, therefore, express or implied. It is said to be general or special with reference to its object, i.e., according as it is confined to a single act or is extended to all acts connected with a particular employment. 2, To use all necessary care. 3, To render an account.
Agents are either joint or several.
It is a general rule of the common law, that when an authority is given to two or more persons to do an act, and there is no several authority given, all the agents must concur in doing it, in order to bind the principal. As to the persons who are capable of becoming agents, it may be observed, that but few persons are excluded from acting as agents, or from exercising authority delegated to them by others. It is not, therefore, requisite that a person be sui juris, or capable of acting in his own right, in order to be qualified to act for others. Infants, femes covert, persons attainted or outlawed, aliens and other persons incompetent for many purposes, may act as agents for others. But in the case of a married woman, it is to be observed, that she cannot be an agent for another when her husband expressly dissents, particularly when he may be rendered liable for her acts.