Section 5

Every instrument purporting to create a power of attorney of which a true copy or an office copy has been deposited in the office of the Registrar or a Senior Assistant Registrar in accordance with this Act or any law repealed by this Act whether before or after the commencement of this Act, shall, so far as the said instrument is valid and so far as may be compatible with the terms of the instrument, continue in force until notice in writing of the revocation thereof by the donor, or of the renunciation thereof by the donee, has been deposited in every office in which the office copy or true copy thereof has been so deposited, or either the donor or the donee has died or the donee has become of unsound mind, or the donor has been adjudged to be of unsound mind or a receiving order has been made against him in bankruptcy.