Agent, in law, a person appointed to perform an act fur another, He may be either special or general, or may be appointed either expressly or impliedly. No form of appointment is required. An agent may be created either by deed, or by a simple letter, or by word of mouth. To execute legal instruments, the authority must be equal in value with the instrument to be executed; thus a power to sign and execute deeds must be created by a power under seal. Some persons are agents by the very nature of their business, such as attorneys, auctioneers, bailiffs, brokers, shipmasters, factors, and others. The agent may bind his principal by his acts. Such liability must necessarily be brought within the scope of his authority; thus, the captain of a ship could not bind his owners in the purchase of a piece of land. The agent entering into a contract on behalf of a principal whose name he discloses is protected from personal liability; but, if acting on behalf of a principal unknown, he is himself liable, unless the third party elect to proceed against the principal. A professional agent is bound to exercise due diligence, and to bring a fair degree of skill and knowledge to the discharge of the duties he undertakes.

If he be an unprofessional agent, he is still bound to exercise the ordinary judgment of a prudent man in the conduct of his own affairs. The circumstance of his being a gratuitous agent does not alter the liability of the agent to the principal in this respect. The limits of an agent's powers must be determined by the nature of his instructions. If special, he is limited to their strict letter; if general, he must act for the best interest of his principal, and the usages of trade and commerce will have considerable weight in determining the propriety of his conduct. He is bound to give early notice of all occurrences affecting his principal's interests; he is bound to account for funds immediately on their receipt, and even for the usufruct of the same if retained or employed by him; he may not buy from nor sell to his principal, unless by express assent; and in some cases contracts for the benefit of a person acting in a fiduciary capacity are absolutely void. The rights of an agent are to reimbursement of all charges and expenses which he may have incurred in the proper discharge of his duties, and not caused by his own carelessness or negligence.

He is also entitled to remuneration of a reasonable character for his services; and lastly, he is entitled to indemnity against the consequences of all acts done by him on behalf of his principal within his powers, provided that such acts are not wrongful to third parties, in which case the agent is personally liable. For the more complete protection of his rights in these respects, he has a lien upon all property of his principal placed in his hands. - The position of third parties may be inferred from the foregoing. The agent may, in his dealings with third parties, bind his principal in all matters fairly within the scope and object of his employment. If he exceed his powers, the third party has no claim whatever on the principal; the claim which the third party may have on the agent must depend on the nature of the case, and in particular on the fact of his principal being disclosed. Public officers, whether acting within their powers or not, are not liable for contracts entered into as such public officers. For wrongful acts and injuries (not of a criminal character) committed by agents, such as trespasses under color of law, or accidents resulting from negligence, the principal may be made liable, provided that the agent's acts be incontestably within the line of his duty.

But the perpetrator of a wrong not being entitled, by the policy of the law, to shield himself behind a principal, the agent is liable as well as the principal.