Emily Dickinson Lexicon

SIL'I-CUM, or SIL-I'CIUM, n. [or SIL'I-CON. L. silex, flint.]

A dark, nut-brown elementary substance, destitute of a metallic luster, and a non-conductor of electricity. It is incombustible in atmospheric air, and in oxygen gas, and infusible by the blow-pipe. It is neither dissolved nor oxydized by sulphuric or nitric acids, but a mixture of the nitric and fluohydric acids dissolves it readily. Its external characters are much altered after exposure to a high temperature.