alligation

n. [ L. alligatio. ] 1. The act of tying together or attaching by some bond, or the state of being attached. [ R. ] [ 1913 Webster ]

2. (Arith.) A rule relating to the solution of questions concerning the compounding or mixing of different ingredients, or ingredients of different qualities or values. [ 1913 Webster ]

☞ The rule is named from the method of connecting together the terms by certain ligature-like signs. Alligation is of two kinds, medial and alternate; medial teaching the method of finding the price or quality of a mixture of several simple ingredients whose prices and qualities are known; alternate, teaching the amount of each of several simple ingredients whose prices or qualities are known, which will be required to make a mixture of given price or quality. [ 1913 Webster ]