Section 148. The commission is hereby authorized and empowered to accept and use gifts made unconditionally by will or otherwise for carrying out the provisions of sections one hundred and twenty-nine to one hundred and forty-nine, inclusive. Gifts made under such conditions as in the judgment of the commission are proper and consistent with said provisions may be so accepted and shall be held, invested, reinvested and the principal and interest may be used in accordance with the conditions of the gift and may be expended under the order or the approval of the commission without specific appropriation.