SECTION 1. Section three of Act Numbered Thirty-nine hundred and twelve is hereby amended to read as follows:
"SEC. 3. All balances of the several appropriations made by this Act the destination of which has not been determined by proper authority on December thirty-first, nineteen hundred and thirty-two, and all balances of appropriations remaining free or unexpended on December thirty-first, nineteen hundred and thirty-three, shall revert to the unappropriated funds in the Insular Treasury, and thereafter shall not be available for expenditure except upon appropriation by the Legislature."