The governing body of any municipality may appropriate in the annual budget for the use of the free public library of such municipality a sum equal to the amount of the money paid into the general treasury by the free public library in the preceding fiscal year. The sum so appropriated shall be available for expenditure by the board of trustees of the free public library of the municipality for library purposes, shall be in addition to sums otherwise appropriated by law for library purposes and shall be controlled by the same laws as other budget appropriations.
N.J.S. § 40:54-18