The trustees of the said, the Pennsylvania state college, are hereby authorized to sell the farms commonly known as the eastern and western experimental farms, or either of them, at the highest price at which they can be sold, at public or private sale, as a whole or in parcels, after at least sixty days' notice of such sale being given weekly in two of the newspapers, published in the county where such farm is located. The proceeds of such sale shall be paid by said trustees into the state treasury, with satisfactory evidence to the governor and treasurer that such sale was conducted in good faith, according to the requirements of this act, and shall there be held as a special fund, to be invested in the bonds of the state, or otherwise, the interest on which, at six per centum per annum, shall be paid by the state treasurer, in equal quarterly instalments, on the first day of January, April, July, and October in each and every year, to the said trustees of the state college, to be used by them for the sole and exclusive purpose of maintaining a mechanical workshop and chemical laboratories, and of conducting educational and scientific experiments on the experimental farm located at the state college and laboratory tests and investigations connected therewith; and the principal of said proceeds is hereby inviolably appropriated and set apart as, and for the uses, herein prescribed: Provided, That, before any portion of the income thereof shall be paid to the said trustees, they shall execute and file with the secretary of the commonwealth an agreement to expend the whole of such income in the manner, and for the purposes, herein designated, and shall annually make to the governor a full statement of their income and expenditures under this head: And provided further, That nothing contained in this act shall be construed to release the said trustees from the obligation to maintain a well equipped experimental farm near the college, as now required by law, or to impair or modify any other obligation or agreement now existing between the state of Pennsylvania and said state college, except as herein expressly provided.