In the management of a city infirmary, in the care and treatment of the inmates thereof, and in the erection, enlargement, or repair of any building for infirmary purposes, or of any addition thereto, the director of public safety shall have the same powers, be governed by the same regulations, and perform the same duties, as far as applicable, as are vested in a board of hospital commissioners established under section 749.04 of the Revised Code in relation to municipal hospitals. The power of the legislative authority in relation thereto shall be the same, so far as applicable, as provided to the legislative authority by sections 749.01 to 749.34 of the Revised Code, in relation to hospitals.