 If a smaller amount than the original tax becomes customary in a diocese, the bishop must be content with this reduced pension, nor can he command a return to the higher sum (S. C. C. in Amalph., 1705).In general it is presumed that the quantity of the cathedraticum will be determined by reasonable custom according to the exigencies of various dioceses and countries.Where custom has not fixed the sum, the S. Congregation of the Council declared that either the amount paid by a neighbouring diocese or the equivalent of the original two solidi must be taken as the proper tax (In Albin., 1644).