The county commissioners of every county establishing a hospital as provided for in this act may incur or increase the indebtedness of the county, in accordance with the Municipal Borrowing Law, to an amount sufficient to pay the cost of acquiring a site and of erecting, constructing and equipping the said hospital, by issuing coupon bonds at a rate of interest not exceeding six per centum and payable within thirty years from the date of issue. The county commissioners shall levy an annual tax in an amount necessary to pay interest and sinking fund charges upon such bonds.
16 P.S. § 5325