CORROSIVE sublimate, an old name for the oxymuriate of mercury, or, as it is called in the shops, muriated mercury. If muriatic acid be added to the yellow sul phate of mercury, or to the nitrate of mer cury, muriate of mercury is formed, which is soluble in water, and which, on account of its properties, was formerly called corrosive sublimate, or corrosive muriate of mercury.
To obtain it, in the large way, the fol lowing process is mentioned by Mr. Mur ray : mix together equal parts of dry oxy nitrate of mercury, decrepitated common salt, and calcined sulphate of iron. One third of a matrass is filled with this mix ture ; the vessel is placed in a sand-bath, and gradually heated to redness. When the apparatus is cold, oxymuriate of mer cury is found sublimed in the upper part of the matrass.
Oxymuriate of mercury, when obtained by sublimation, is in the form of a beauti ful white semitransparent mass, compos ed of very small prismatic needles. By evaporation, it yields cubes or rhomboidal prisms, or more commonly quadrangular prisms, with their sides alternately nar rower, and terminated by dihedral sum mits ; its specific gravity is .51 ; its taste is excessively acrid and caustic, and it leaves, for a long time a very disagree able styptic metallic impression on the tongue. When swallowed, it is one of the most virulent poisons known, producing violent pain, nausea, and vomiting, and corroding in a very stunt time the sto mach and intestines. It is soluble in about
20 parts of cold water. Boiling water, according to Macquer, dissolves half its weight of it. According to Wenzel, water, when boiled over this salt, dissolves very nearly one-third of its weight of it. Alco hol, according to Macquer, at the tempera ture of 70°, dissolves three-eighths of its weight, and 100 parts of boiling alcohol dissolves 88 parts of it. It is not altered by exposure to the air. When heated, it sublimes very readily ; and while in the state of vapour, it is exceedingly danger ous to those who are obliged to breath it.
It is soluble in sulphuric, nitric, and muriatic acids; and may be obtained again by evaporation unaltered. It is decompos ed by the fixed alkalies, and its oxide precipitated of a yellow colour, which soon becomes brick red. This decompo sition renders oxymuriate of mercury a useful test for ascertaining the presence of fixed alkalies in solution. If liquid oxymuriate of mercury be dropt into a solution containing the smallest portion of alkali, the brick-red precipitate appears. Ammonia forms with it a triple salt. The component parts of this salt are, accord ing to Chenevix, Oxide of mercury . 82 Acid 18 100 Externally, this substance is employed as an escarotic for destroying fungous flesh.