against any officer or soldier. The sajd-court, . shall consist of one or more officers, not ex: ceeding three, and a judge advocate, or other. suitable person, as a recorder, to reduce the proceedings and evidence to writing; all of whom shall be sworn to the performance of their duty. Rev. St. § 1342, arts. 115, 116 (U. S. Comp. St. 1901, pp. 970, 971.)