§ 541.
In lieu of all existing taxes, every association shall pay to the Treasurer of the United States, in the months of January and July, a duty of one-half of 1 per centum each half year upon the average amount of its notes in circulation.
(R.S. § 5214; [Mar. 3, 1883, ch. 121, § 1], [22 Stat. 488].)