Restrictions on general appropriation bill.

The general appropriation bill shall embrace nothing but appropriations for the ordinary expenses of the executive, legislative, and judicial departments of the state, for interest on the public debt, and for the public schools. The salary of no officer or employe shall be increased in such bill, nor shall any appropriation be made therein for any officer or employe unless his employment and the amount of his salary have already been provided for by law. All other appropriations shall be made by separate bills, each embracing but one subject.