The Secretary of the Treasury is authorized and directed to pay, out of any unexpended balances of appropriations for contingent expenses of land offices, for the expenses of hearings in land entries and the expenses of depositing public moneys, such sums as have been or may be disbursed by officers designated by the Secretary of the Interior acting as special disbursing agents at United States land offices, before the receipt of Government funds: Provided, That no payment shall be made under this section in excess of the amount appropriated by the Congress for the particular purpose in each instance and for the fiscal year in which such disbursements were made: Provided, That all such disbursements shall have been or shall be made in pursuance of law in carrying out departmental regulations or to meet authorizations by the Secretary of the Interior or such officer as he may designate: Provided further, That the accounts containing such items shall have been duly approved by the Secretary of the Interior or such officer as he may designate.