(From corrodo, to eat away). Corrosiveorcorrodingmedicines,also called cathaeretica. They are divided into, 1st, The mild, such as burnt alum, the ashes of green wood, calomel, calx hydrargyri alba, and zincum vitriolatum purificatum; 2d, The strong, as hydrargyrus nitratus ruber, colcothar vitrioli, trochisci de minio Vigonis; 3d, The strongest, as bu-tyrum antimonii, lapis infernalis,hydrargyrus muriatus, aqua kali,et acidum vitriolicum. Corrosives generally destroy the life of the part to which they are applied, either by their stimulus exhausting the excitability, or, in some instances, by their affinity for moisture. After this destruction of life they differ by acting chemically on the dead matter, and destroying it. Of the corrosives which destroy life, without acting on the dead matter, are the savine, the euphorbium, the gall nut powder, sugar, and the cevadilla (the Indian caustic barley). Every active stimulant produces indifferent degrees the same effects. Those which seem to destroy and decompose a part by their affinity for moisture, are the alkalis, lime, and perhaps barytes. These belong, also, to the second class, viz. corrosives, which act on the dead annual matter. Among them we may enumerate the argentum nitratum (lunar caustic,) butter of antimony, blue vitriol, corrosive sublimate, calomel, verdigris, red precipitate, burnt alum, and the mineral acids. These are all oxygenated preparations, and probably destroy life by their excess of stimulus.