The state is authorized to become indebted and to issue interest bearing bonds, in addition to those heretofore authorized and sold, in an aggregate principal amount not exceeding $3,000,000. The proceeds derived from the sale of said bonds shall be used solely for the purpose of paying the expenses incurred in the sale and issuance thereof and for the acquisition of sites for and the construction, reconstruction, alteration, improvement and equipment of building facilities, including the renewal or replacement of structural parts, at the Alabama Institute for Deaf and Blind. Said bonds shall be sold only at a duly advertised public sale or sales, upon sealed bids or at auction, to the bidder whose bid reflects the lowest net interest cost to the state for the bonds offered for sale, and shall be sold at not less than their face value plus accrued interest thereon. Said bonds shall be direct general obligations of the state and for the prompt and faithful payment of the principal thereof and interest thereon the full faith and credit of the state are hereby irrevocably pledged. In addition thereto, there is hereby specially and irrevocably pledged for payment of the principal of and interest on said bonds, pro rata and without priority of one bond over another by reason of prior issuance or otherwise, so much as may be necessary for said purpose of those portions of the state sales tax and the state use tax in effect at the date of the adoption of this amendment which are required by law at the date of the adoption of this amendment to be paid into the Alabama special educational trust fund. The said special pledge shall create a charge on the tax proceeds herein specially pledged prior to all other charges or expenses for educational or any other purposes whatsoever; provided, that in the event any other bonds should be issued under the authority of any other amendment to the Constitution proposed by the 1957 regular session of the legislature, or by any public corporation created pursuant to any statute enacted at said session, for payment of the principal of and interest on which the said taxes or any portion thereof should be pledged in such other constitutional amendment or in or pursuant to authority of such statute, then the special pledge of the said taxes herein made shall be on a parity with the pledge or pledges of said taxes or portion thereof for the benefit of such other bonds. The bonds issued under this amendment and the income therefrom shall be exempt from all taxation in the state of Alabama. The provisions of section 261 of the Constitution of Alabama shall not be deemed to apply to the tax proceeds so specially pledged or to the proceeds from any bonds issued hereunder. The legislature shall adopt appropriate enabling legislation to carry out the intent and purpose of this amendment.