There is appropriated out of any moneys in the state treasury, as a standing and continuing appropriation, such sum as may be necessary to pay:

1. The mileage and per diem of the members of the legislative assembly;

2. The per diem of officers and employees of the legislative assembly;

3. The expense of investigating committees when authorized by the legislative assembly; and

4. Necessary postage, express, telegrams, telephone, and such other miscellaneous expenses as may be authorized by the legislative assembly, except printing.