Decomposition is the rather comprehensive term applied to the breaking up of complex substances, or substances of delicate stability, into others which are less complex or more stable. Such breaking up is very familiar in many chemical changes, and may result from increase of temperature, the action of light, the action of ferments and micro-organisms, and so on. The ordinary process of alcoholic fermentation is a good example of decomposition, which takes place in the presence of, and is dependent upon, the life and growth of yeast in the saccharine solution. Similarly the oxidation of nitrogenous organic matters with formation of nitrates, if not dependent upon, is greatly accelerated by the presence of a micro-organism.
The term decomposition is constantly applied in chemistry to the changes which compounds undergo in the most varied circumstances when subjected to change of conditions. See also CHEMISTRY, FERMENTATION, PUTREFACTION.