An agent may appoint a substitute when the principal has not forbidden him to do so, but he shall be liable for the acts of the substitute:\n(1) When the power to appoint such substitute was not granted him.\n(2) When such power was granted him, but without designating the person, and the person appointed is well known to be incapacitated or insolvent.\nWhat is done by the substitute, appointed against the prohibition of the principal, shall be void.\nHistory —Civil Code, 1930, § 1612.
Puerto Rico Legal Code