Emily Dickinson Lexicon

CAUS'TIC, n.

In medicine, any substance which applied to living animals, acts like fire, in corroding the part and dissolving its texture; an escharotic. [See Causticity.] – Coxe. Encyc. Lunar caustic, a preparation of crystals of silver, obtained by solution in nitric acid, and afterwards fused in a crucible. It is a nitrate of silver. – Nicholson. Caustic curve, in geometry, a curve formed by a coincidence of rays of light reflected from another curve. – Encyc.