Miss. Code Ann. § 29-3-111

All moneys heretofore or hereafter derived from the leasing of said lands for oil, gas and mineral purposes, including any bonus or delay rental payable under such leases, and all moneys derived from the annual payment of rents from the leasing of said lands for agricultural, residential, commercial, industrial, grazing or other purposes, or derived as interest upon loans or investments of principal funds, and all moneys heretofore or hereafter derived from the sale of timber, may be expended for any of the purposes authorized by law. In cases where said moneys have been transferred to the principal fund and it is determined to expend same for any of the purposes authorized by law, such moneys shall be transferred to the proper fund for expenditure upon order of the board of education.