That from and after the passage and approval of this act N.M. Stat. Ann. § 6-13-1 to 6-13-26, all permanent funds thereafter derived from the sale or disposition of the lands held in trust for any of said institutions shall be invested in bonds of the United States or of the state of New Mexico, the income from which shall likewise form a part of the pledged income for the payment of the principal and interest on bonds issued by the board of any such institution under the provisions of this act.