Section 66. Subject to appropriation from the General Fund, the tools, implements and materials required for use in manufacturing in any of the correctional institutions of the commonwealth, and such necessary machinery to replace any which becomes unfit for use or is destroyed by fire or by malicious acts of prisoners or to establish new trades or industries, may be purchased through the state purchasing agent as provided by section twenty-two of chapter seven, or with his approval as provided by section fifty-two of chapter thirty, or by or under the direction of the purchasing bureau as provided in section fifty-one of chapter thirty, by the commissioner, or by the superintendent, or any agent appointed by such superintendent with the approval of the commissioner.