The state treasurer is the trustee for all funds apportioned to the state under any act of congress and he is directed to enter into agreements with, and to comply with the rules and regulations of, such agencies of the federal government as are necessary to procure for the state grants of federal aid to education. Any funds received under any act of congress shall be held by the state treasurer in special funds designated in accordance with the purposes of the grant made and shall be paid out by him only on warrant of the secretary of finance and administration. Warrants shall be issued only upon voucher of the superintendent of public instruction for disbursements other than for rural library service. Disbursements made for rural library service shall be made only upon voucher issued by the state librarian.