Section, acts June 25, 1948, ch. 646, 62 Stat. 950; May 24, 1949, ch. 139, 95, 63 Stat. 103; Oct. 5, 1949, ch. 601, 63 Stat. 704; July 7, 1952, ch. 581, 66 Stat. 439; July 28, 1955, ch. 424, 3, 69 Stat. 394, related to payment of witnesses fees to officers and employees of the United States. See sections 5515, 5537, 5751, and 6322 of Title 5, Government Organization and Employees.