premise: in acid salt two or more <mask> of acid unite with one or more <mask> of base
hypothesis: the best context for <mask> here is A combining unit, whether an atom, a radical, or a molecule; but not That comparative quantity by weight of an element which possesses the same chemical value as other elements, as determined by actual experiment and reference to the same standard. Specifically: (a) The comparative proportions by which one element replaces another in any particular compound.