Michigan Compiled Laws, Chapter 4. Legislature § 4.181

Sec. 1. Whenever any witness shall be subpoenaed to appear before a committee of the legislature by authority of either branch thereof the compensation of such witness shall be $5.00 for each day, or any portion thereof, and for traveling at the rate of 15 cents per mile in going to the place of attendance to be computed from the residence of such witness, and the amount of compensation due to such witness shall be paid in the same manner as other legislative expenses are paid, out of moneys appropriated to the legislature.