The district attorney of the Fourth Judicial District of this state shall receive, in addition to the salary now paid him by the state, an annual salary of eleven thousand seven hundred fifty dollars, payable monthly on his own warrant by the parishes comprising the fourth judicial district and apportioned as follows:
(1) By the parish of Morehouse, the sum of four thousand two hundred fifty dollars per annum.
(2) By the parish of Ouachita, the sum of seven thousand five hundred dollars per annum.