Section, acts June 20, 1874, ch. 343, 3, 18 Stat. 123; Dec. 23, 1913, ch. 6, 20, 38 Stat. 271; May 29, 1920, ch. 214, 1, 41 Stat. 654, provided that every national banking association was to establish reserve in Treasury for redemption of notes by Treasurer of United States, forward notes unfit for use to Treasurer for disposition, and reimburse expenses of Treasury.