Any county of this state now or hereafter having a population of more than one hundred thousand according to the latest available census, and in which there is located a municipality of one hundred thousand or more, acting by and through its board of supervisors, is hereby authorized and empowered to contribute the sum of one million dollars ($1,000,000.00) toward the construction, erection and equipping of educational facilities to be utilized by the University of Mississippi within such county, by the board of trustees of state institutions of higher learning.