The general fund consists of moneys received into the treasury and not specially appropriated to any other fund. All necessary interest on registered warrants drawn upon the general fund shall be paid out of the general fund, and there is hereby appropriated out of the said general fund so much as may be necessary to pay such interest. When the state treasurer pays any such warrant on which interest is due, he must note on the warrant the amount of interest paid thereon and enter on his account the amount of any such interest distinct from the principal.