[257-4; Comp., 3759.] Disbursements SECTION  645 . Disbursement of Government Funds in General. — Revenue funds shall not be paid out of any treasury except in pursuance of lawful appropriation or other specific statutory authority. Trust funds shall not be paid out of any treasury except in fulfillment of the purpose for which the trust was created or fund received, and upon authorization of the legislative body, or head of Bureau, Office, or other branch of the Government, having co ntrol thereof. Insular revenue and trust funds, and like funds of the city of Manila, shall not be withdrawn from the Insular Treasury except upon warrant; but nothing herein shall be construed to prevent disbursing officers from maintaining checking accounts in the Insu lar Treasury or Philippine National Bank with funds so withdrawn, subject to such regulations as the Insular Auditor shall prescribe. HCITcA [1792-18,19.] SECTION  646 . Requirement of Approval and Endorsement of Head of Office.  — Payments to creditors shall be made only upon the specific approval of the chief of Bureau or head of Office concerned, or his duly authorized representative, or if there be no such  officer, upon the approval of the Department head, endorsed upon the warrant or voucher effecting such payment. [1792-18.] SECTION  647 . Persons Authorized to Draw Warrants for Payment of Insular Funds.  — Warrants upon the Insular Treasury shall be drawn by the chief of Bureau or Office having control of the appropriation or fund against which such warrants are chargeable or by  such subordinate as shall be designated for such duty by the proper Department head. Warrants chargeable to Insular appropriations or funds not under the control of a Bureau or Office shall be drawn by such officer as shall be specified by law or, in the absence of such, designated by the Governor-General. [1792-18.] For the city of Manila all warrants shall be drawn by the secretary of the Copyright 2012 CD Technologies Asia, Inc. and Accesslaw, Inc. Philippine Law Encyclopedia 2011 203 ARTICLE  VII