§ 72

Subject to appropriation, the bills for tools, implements, machinery and materials purchased for, and the salaries of persons employed in, the correctional institutions of the commonwealth, under sections fifty-one to fifty-eight, inclusive, sections sixty, sixty-one, and sixty-six to sixty-nine, inclusive, shall be paid monthly by the commonwealth, upon schedules prepared and sworn to by the superintendents and approved by the commissioner. Bills for tools, implements, machinery and materials purchased by, and the salaries of persons employed in, the jails and houses of correction under said sections shall be paid monthly by the county, upon schedules prepared and sworn to by the superintendent or keeper and approved by the commissioner. The schedule of bills for tools, implements and machinery and of bills for materials and salaries shall be kept separate from each other and from the schedules of bills incurred for the maintenance of the correctional institutions of the commonwealth, jails or houses of correction.