With the consent of the Governor, said bonds so purchased and held in trust may be sold from time to time by the Department of Finance, if it is deemed for the best interest of the sinking fund that said transactions be had, and the proceeds held or reinvested from time to time, provided always said fund be kept intact and be used at the maturity of the said bonds for the retirement of the same. Bonds in said sinking fund on maturity dates shall be cancelled and destroyed as other bond obligations of the state are handled when paid at maturity.
Ala. Code § 41-4-11 (1975)