228 MERCURY 



mobility. A cold of 39 below zero of Fahrenheit, or 40 Cent, is required for its 

 congelation, in -which state its density is increased in the proportion of 10 to 9, or it 

 becomes of specific gravity 15'0. At a temperature of <562 F. it boils and distils off in 

 an elastic vapour of specific gravity 6*976, which, being condensed by cold, forms puri- 

 rified mercury. 



Mercury combines with great readiness with gold, silver, zinc, tin, and bismuth, 

 forming, in certain proportions, fluid solution of these metals. Such mercurial alloys 

 are called amalgams. This property is extensively employed in many arts ; as in ex- 

 tracting gold and silver from their ores ; in gilding, plating, making looking-glasses, 

 &c. (See AMALGAM.) Humboldt estimates at 16,000 quintals, of 100 Ibs. each, 

 the quantity of mercury annually employed in the treatment of the ores of the mines 

 of New Spain ; three-fourths of which came from European mines. 



The mercurial ores belong principally to the following four species : 



1. Native quicksilver. It occurs in most of the mines of the other mercurial ores, 

 in the form of small drops attached to the rocks, or lodged in the crevices of other ores. 



2. Native silver amalgam. It has a silver-white colour, and is more or less soft, 

 according to the proportion which the mercury bears to the silver. Its density is 

 sometimes so high as 14. A moderate heat dissipates the mercury, and leaves the 

 silver. Klaproth states its constituents at silver 36, and mercury 64, in 100 ; but 

 Cordier makes them to be, 27i silver and 72 mercury. It occurs crystallised in 

 the cubic system. It has been found in the territory of Deux-Ponts ; at Rozenau and 

 Niderstana, in Hungary, in a canton of Tyrol, at Sala in Sweden, at Kolyvan in 

 Siberia, and at Allemont in Dauphiny ; in small quantity at Almaden in Spain, and at 

 Idria in Carniola. In the rich silver mines of Arqueros, near Coquimbo, this mineral 

 occurs, having the composition, silver 86'49, mercury 13'51. This is the arqmrite of 

 Domeyko. By the chemical union of the mercury with the silver, the amalgam, which 

 should by calculation have a specific gravity of only 12'5, acquires that of 14-11. 

 See AMALGAM ; AEQUERITE. 



3. Sulphide of Mercury, commonly called Cinnabar, is a red mineral of various 

 shades ; burning at the blowpipe with a blue flame, volatilising entirely with the smell 

 of burning sulphur, and giving a quicksilver coating to a plate of copper held in the 

 fumes. Even the powder of cinnabar rubbed on copper whitens it. Its density varies 

 from 6'9 to 10'2. It becomes negatively electrical by friction. Analysed by Klaproth, 

 it was found to consist of mercury 84'5, sulphur 14'7o. Its composition, viewed as a 

 bisulphuret of mercury, is, mercury 86 - 2, sulphur 13 - 8. Its chief localities are Idria, 

 in Carniola ; Almaden, in Spain ; and New Almaden, in California. It is found also 

 at Wolfstein, in Rhenish Bavaria ; in Saxony, in the Hartz ; in Carinthia, Styria, 

 Bohemia, Hungary, and Tuscany ; in the Ural and Altai ; in China, Japan, Queensland, 

 Mexico, and Peru. See CINNABAR. 



A bituminous sulphide of mercury appears to be the base of the great exploration of 

 Idria ; it is of a dark liver-red hue, and of a slaty texture, with straight or twisted 

 plates. It exists in large masses in the bituminous schists of Idria. M. Berard 

 mentions also the locality of Miinster-Appel, in the duchy of Deux-Ponts, where the 

 ore includes impressions of fishes, curiously spotted with cinnabar. 



The compact variety of Idria ore seems very complex in composition, according 

 to the following analysis of Klaproth : Mercury, 81'8 ; sulphur, 13'75 ; carbon, 2 - 3 ; 

 silica, 0'65; alumina, 0'55 ; oxide of iron, 0-20; copper, 0'02 ; water, 0'73; in 100 

 parts. M. Berard mentions another variety from the Palatinate, which yields a large 

 quantity of bitumen by distillation ; and it was present in all the specimens of these 

 ores analysed by Dr. Tire for the German Mines Company. At Idria and Almaden 

 the sulphides are extremely rich in mercury. 



4. Chloride of mercury, or Native Calomel, commonly called Horn-mercury. This 

 mineral, which is very rare, occurs in very small crystals of a pearl-grey or greenish- 

 grey colour, or in small nipples which stud, like crystals, the cavities, fissures, 

 or geodes among the ferruginous gangues of the other ores of mercury. It is brittle, 

 and entirely volatile at the blowpipe ; characters which distinguish it from horn 

 silver. See CALOMEL. 



Ores of mercury are found in rocks of almost every geological age. At Almaden, 

 in Spain, they occur in deposits at the contact of Silurian slates with a metamorphic 

 rock locally called fraylfsca. At Ripa, in Tuscany, the veins traverse mica-slate. 

 The deposits at Deux-Ponts, or Zweibriicken, in the Palatinate, are said to be in red 

 sandstones of Permian age, and in the scchstcin, or magnesian limestone. At Idria, 

 in Carniola, the ores are disseminated through shales and black compact limestones 

 of the Jurassic period; and at New Almaden, in California, the rocks containing the 

 cinnabar belong to the Cretaceous period. Cinnabar is now in course of formation in 

 some of the siliceous deposits thrown down from the hot springs of California and 

 Nevada. 



