The board of county commissioners may receive bequests, donations, and gifts of real and personal property and money to promote and advance the cause of education in the county. All property and money so received by the board, or which has been bequeathed and bestowed upon such board and remains undisposed of, may be paid to any incorporated institution of learning in the county, or a part may be used each year to defray the expenses of the teachers institute, upon such terms as the board prescribes, having reference to the terms of the trust and safety of the fund and its proper application.