AGENCY, LAW or. An agent is a person authorised by another (called the principal) to act on his behalf. An agent authorised to act for a special purpose only is called a particular agent ; if there is a general authority to act within a given sphere, the agent is called a general agent. A partnership is an instance of general agency in the widest sense, each partner being, as a rule, considered the agent of his copartners for all purposes coming within the scope of the partnership business. An agent may not, according to English law, derive any concealed profit from his agency, and he may not, as a general rule, delegate his authority to another person. An agent may in his dealings with third parties act as principal, or he may state the fact of the agency without disclosing the name of the principal, or he may deal on behalf of a named principal. The rules of law concerning the liabilities and mutual relations of the various parties in all these cases are too complicated to be stated here, and the general rules are often modified by the customs of particular localities or particular trades. The authority of an agent acting on behalf of a corporate body cannot extend beyond the limits imposed upon the sphere of action of the corporation either by Act of Parliament, or by the charter of incorporation or by the memorandum of association (see ULTRA VIREO. a. B.