When a promissory note authorized by § 13-19-1 has been issued and not paid in full upon the maturity thereof, then thereafter, no cash receipts, from the collection of taxes or from the collection of tuition charges, shall be expended for any purpose except the retirement of principal and interest of registered warrants and promissory notes outstanding against the fund into which said revenue has been received, until all of said registered warrants and promissory notes shall have been retired.
SDCL 13-19-6