Revocation of agency. An agency is dissolved or determined in several ways:-
(I) by the act of the principal, either
(a) Express, as
(1) By direct and formal writing, publicly a advertised;
(2) By informal writing to the agent privately;
(3) By parol; or
(b) Implied from circumstances as by appointing another person to do the same act, where the authority of both would be incompatible.
The exceptions to the power of the principal to revoke his agent's authority at mere pleasure are--
(1) When the principal has expressly stipulated that the authority shall be irrevocable, and the agent has also an interest in its execution.
(2) Where an authority or power is coupled with an interest, or is given for a valuable consideration, or is a part of a security, unless there is an express stipulation that it shall be revocable.
(3) When an agent's act in pursuance of his authority has become obligatory, for nemo potest mutare consilium suum in alterius injuriam.
(II.) By the agent's giving notice to his principal that he renounces the agency; but the principal must sustain no damage thereby; otherwise the agent would be responsible therefor.
(III.) By operation of law, as
(a) By the expiration of the period during which the agency was to exist or to have effect.
(b) By a change of condition or of state, producing an in capacity of either the principal or the agent, as
(1) Mental disability established by inquisition, or where the party is placed under guardianship.
(2) Bankruptcy, excepting as to such rights as do not pass to the trustee under the adjudication.
(3) Death, unless the authority is coupled with an interest in the thing vested in the agent.
(4) By the extinction of the subject of the agency.
(5) By the ceasing of the principal's powers.
(6) By the complete execution of the trust confided to the agent, who then is functus officio. Consult Halsbury's Laws of England tit. 'Agency.'
As to the law when the agent is constituted by power of attorney, see POWER OF ATTORNEY.