The act of imbibing till no more can be received. A fluid that holds in solution as much of any substance as it can dissolve, is said to be saturated with it. But saturation with one substance does not deprive the fluid of its power of acting on, and dissolving some other bodies, and in many cases it increases this power. For example, water saturated with common salt will dissolve sugar; and water saturated with carbonic acid will dissolve iron, though without this addition its action on this metal is scarcely perceptible. The word saturation is likewise used in another sense by chemists: the union of two principles produces a body, the properties of which differ from those of its component parts, but resemble those of the predominating principle. When the principles are in such proportion that neither predominates, they are said to be saturated with each other; but, if otherwise, the more predominant principle is said to be sub-saturated, or under-saturated, and the other supersaturated, or over-saturated.