Emily Dickinson Lexicon

SI-LIC'IC-AC'ID, n. [SI-LIC'IC AC'ID.]

An acid, according to Thomson, composed of one equivalent of silicum, silicium or silicon, and one of oxygen, or according to Berzelius, one of silicum, silicium or silicon, and three of oxygen. When pure it is a light white powder, which feels rough when rubbed between the fingers. It is both inodorous and insipid. It combines with bases, forming salts, which are called silicates.