Emily Dickinson Lexicon

DE-COM-PO-SI'TION, n.

1. Analysis; the act of separating the constituent parts of a substance, which are chimically combined. Decomposition differs from mechanical division, as the latter effects no change in the properties of the body divided, whereas the parts chimically decomposed have properties very different from those of the substance itself.
2. A second composition. [In this sense, not now used.] – Boyle.