If it appears to the Secretary of State, in the case of a patient who is for the time being liable to be detained or subject to guardianship under this Act (otherwise than by virtue of section 35, 36 or 38 above), that it is in the interests of the patient to remove him to any of the Channel Islands or to the Isle of Man, and that arrangements have been made for admitting him to a hospital or, as the case may be, for receiving him into guardianship there, the Secretary of State may authorise his removal to the island in question and may give any necessary directions for his conveyance to his destination.