Any hospital corporation may anticipate the proceeds from any special county tax required to be paid to it in accordance with the provisions of this division, by issuing securities for any one or more of the purposes for which the tax shall have been voted, and may pledge for the payment of the principal thereof and interest thereon the annual proceeds from the said tax so paid to it; provided, that if any constitutional provisions applicable to the pledge of the said tax shall restrict the portion of such tax proceeds that may be so pledged, then the hospital corporation shall have the power to pledge only that portion of the said proceeds that may be so pledged without violation of the said constitutional provisions. All securities issued under this division shall be payable from the proceeds of the special tax in respect of which they were issued and from such other funds of the hospital corporation as its directors may determine, but this section shall not prohibit payment of the securities from any other funds which may be available therefor under any other provision of law; provided, that in no event shall such securities be payable from such other funds if the effect thereof would be to subject such securities to any constitutional requirement that they be authorized by vote of the qualified voters. Said securities shall be the obligation only of the hospital corporation issuing the same in accordance with the terms of such securities. No county shall, in any event, be liable for any obligation created by a hospital corporation or by the issuance of securities thereby, nor shall said securities be construed to be an indebtedness of, or against, any county or municipal corporation. All securities issued under this division shall have preference over claims for salaries or other operation expenses or any other purposes. All pledges of the said tax and all contracts made with respect thereto shall take precedence in the order in which they are made and shall create a charge on the proceeds of the said tax prior to the expenses of operation and maintenance of any hospital facilities.