From the accumulated unexpended balances of the revolving fund heretofore appropriated for the purchase of office supplies by the State Budget and Control Board the sum of twenty thousand dollars shall be maintained by the State Treasurer as a permanent and continuing revolving fund for the purchase of office supplies or such other commodities as the General Assembly may hereafter direct, to be administered by the Board. Should the fund exceed twenty thousand dollars at the end of any fiscal year the surplus shall be transferred to the general fund of the State.