6. The Government may, if it considers it necessary for any purpose of this Ordinance, authorise by order in writing any person to take over from any local authority the administration of all or any of its medical and public health services or of any medical institution maintained by the local authority; and the person so authorised may for the purposes of such administration exercise all the powers specified in sub section (2) of section 3 of a person authorised under that sub section; and all charges and expenses incurred by the person authorised under this section shall, except to such extent, if any, as the Government may direct to be paid out of its revenues, be paid out of the funds of the local authority.