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PROPERTIES OF MERCURY.

Mercury, united either to muriatic, or sulphuric acid, forms theore called horn quicksilver, or corneous mercury. These oresare, in general, semi-transparent, of a grey or white colour,sometimes crystallized, but more frequently in grains. Unitedto oxigen it constitutes the ore called native oxid of mercury.Mercurial ores particularly abound in Spain, Hungary, China,and South America.

PROPERTIES OF MERCURY.

Mercury, or quicksilver, is the only one of the metals thatremains fluid at the ordinary temperature of the atmosphere, butwhen its temperature is reduced to — 40° Fahr. it assumes a solidform. This is a degree of cold, however, that only occurs inhigh northern latitudes, and, in our climate, mercury cannot beexhibited in a solid state, but by means of artificial cold. Whenrendered solid it possesses both ductility and malleability. It cry-stallizes in octahedra, and contracts strongly during congelation.It is divisible into very small globules. It presents a convexappearance in vessels to which it has little attraction, (page 2Q),but is concave in those to which it does adhere. It becomeselectric and phosphorescent by rubbing upon glass, and by agi-tation in a vacuum. It is a very good conductor of caloric, ofelectricity, and of galvanism. The specific gravity of mercury is13.563. Although fluid, its opacity is equal to that of any othermetal, and its surface, when clean, has considerable lustre. Itscolour is white, similar to silver. Exposed to the temperatureof 600 ° Fahr. it is volatilized. When agitated in the air, especiallyin contact with viscous fluids, it becomes converted into a blackoxid. At a temperature nearly the same as that at which it boils,it absorbs about 14 or 16 per cent, of oxigen, and then becomeschanged into a red crystallizable oxid, which is spontaneouslyreducible by caloric and light at a higher temperature. Thegreater number of the acids act upon mercury, or are at leastcapable of combining with its oxids. It combines with sulphur