Mississippi Code Title 5. Legislative Department § 5-1-59

Witnesses on behalf of the state subpoenaed to appear before the legislature, or either branch thereof, or any committee authorized to send for witnesses, shall be allowed the same compensation for each day's attendance, and the same mileage allowed to witnesses in the circuit courts. The sum due to each witness shall be ascertained by his own affidavit before the secretary of the senate or clerk of the house of representatives or chairman of the committee before whom he was subpoenaed to appear, who shall give the witness a certificate thereof attaching the affidavit to the same. On production of such certificate the auditor shall issue his warrant on the treasurer therefor, payable out of the legislative appropriation.