8 WAR BORROWING United States, a Treasury certificate of indebtedness may be described as a freely negotiable, short-term government obligation — differing from the evidence ­ of a bank loan in degree of negotiability, from a funded bond in hardly anything more than a shorter term of maturity, from a demand note in nominal non-convertibility upon presentation. In addition to the widest latitude in technical form, a certificate of indebtedness may bear interest or be non-interest bearing. It may have a definite date of maturity or be payable or fundable at the option of the government at any time or after a fixed date. It may be made receivable for all or for certain public taxes or dues or be made acceptable for specific public payments, as bond subscriptions or public land purchases. It may be secured as to interest or principal by assigned tax revenues or prospective loan proceeds, or be protected only by the pledge of public faith. It may be issued in direct discharge ­ of public accounts payable or be marketed or hypothecated as a funded obligation. It may even be vested with limited privileges of circulation or be endowed with full legal tender quality. In the first century and a quarter of our national existence there were six occasions on which the Treasury had recourse to the issue of short-term negotiable obligations: (A) The War of 18x2, (B) The Crisis of 1837, (C) The Mexican War, (D) The Crisis of 1857, (E) The Civil War and (F) The Crisis of 1907. In addition authority was conferred but not exercised for the issue of certificates of indebtedness in connection with the