The grant of land and land scrip hereby authorized shall be made on the following conditions, to which, as well as to the provisions contained in said sections, the previous assent of the several States shall be signified by legislative acts:
First. If any portion of the fund invested, as provided by section 304 of this title, or any portion of the interest thereon, shall, by any action or contingency, be diminished or lost, it shall be replaced by the State to which it belongs, so that the capital of the fund shall remain forever undiminished; and the annual interest shall be regularly applied without diminution to the purposes mentioned in section 304 of this title, except that a sum, not exceeding 10 per centum upon the amount received by any State under the provisions of this subchapter, may be expended for the purchase of lands for sites or experimental farms, whenever authorized by the respective legislatures of said States.
Second. No portion of said fund, nor the interest thereon, shall be applied, directly or indirectly, under any pretense whatever, to the purchase, erection, preservation, or repair of any building or buildings.