CAUSTICS, in physics, an appellation given to medicines of so hot and fiery a nature, that, being applied, consume, and as it were burn, the texture of the parts, like hot iron.
Caustics are generally divided into four sorts; the common stronger caustic, the common milder caustic, the antimonial caustic, and the lunar caustic. See PHARMACY, no 649. 791; and CHEMISTRY, no 196.