where an article is purchased upon terms fixed by contract between the United States Government and the dealer, of which the Government of the Philippine Islands is allowed the benefit. [Ex. Or. 26 (1911).] [231-1; 140-1; Comp., 2054.] [584-6.] SECTION  1900 . Requirement of Requisition . — No order for supplies shall be filled by the Bureau of Supply for any branch of the Government except upon written requisition as hereinbelow provided. [146-6.] SECTION  1901 . Officers Having Authority to Draw Requisitions . — Insular requisitions shall be drawn by the chief of Bureau or Office concerned or other officer having control of the appropriation to which the expenditure is chargeable; provincial requisiti ons shall be drawn by the provincial treasurer; municipal requisitions, by the municipal treasurer; requisitions for the city of Baguio, by the treasurer of said city; and for the city of Manila, by the head of the department of the city government for whi ch the supplies are required. [146-6.] SECTION  1902 . Certificate Showing Existence of Appropriation . — Every requisition must be accompanied by a certificate, signed by the person having control of the disbursement of the fund against which the proposed expenditure is chargeable, showing that a n appropriation therefor exists and that Copyright 2012 CD Technologies Asia, Inc. and Accesslaw, Inc. Philippine Law Encyclopedia 2011 565 ARTICLE  III Requisitions for Supplies ( b ) Where purchase is made of materials, supplies, or other articles needed for the use of a provincial government, such things being procurable in the province at prices deemed by the provincial board to be reasonable. ( c ) Where purchase is made of materials or supplies for use in the construction, repair, or maintenance of a public work upon the occasion of any emergency involving danger to life or property or in any case where the location of the work is remote from Ma nila.