In addition to the expenses now allowed by law to district attorneys pursuant to Section 12-17-191, there shall be paid to district attorneys in all judicial circuits composed of four or more counties the sum of $300.00 per annum for each county of the judicial circuit, over and above one, said additional allowance to be reimbursement for reasonable expenses while in attendance upon court outside of their home county, to be paid from the treasury monthly.
Ala. Code § 12-17-192 (1975)