The donee of a power-of-attorney may, if he thinks fit, execute or do any instrument or thing in and with his own name and signature, and his own seal, where sealing is required, by the authority of the donor of the power; and every instrument and thing so executed and done, shall be as effectual in law as if it had been executed or done by the donee of the power in the name, and with the signature and seal, of the donor thereof.

This section applies to powers-of-attorney created by instruments executed either before or after this Act comes into force.