All state school bonds issued under the provisions of this chapter shall be sold by the said state bond commission upon sealed competitive bids or proposals after advertisement therefor and publication of the notice of such sale in the manner provided by law.
The proceeds of the sale of all state school bonds shall be placed in the "state public school building fund" and shall be expended only for the purposes authorized by this chapter. However, the premium, if any, received for any such bonds and the accrued interest paid thereon, if any, shall be placed in the sinking fund established for the payment of said bonds.