Mercury is found in various parts of the world. Among the principal mines are those of Almaden, near Cordova, in Spain ; Idria, in Carniola ; ViTolfstein and Morsfield, in the Palatinate ; Guanca Velica, in Peru. It is stated by Dr. A. T. Thompson, in his DiJpensatory that most of the mercury used in England is brought from Germany. But, whatever may have been the case formerly, this is not certainly true at present. On the contrary, of 314,286 lbs. of quicksilver im ported into England in 1831, none was brought from Germany: 269,558 lbs. were brought direct from Spain, and 18,714 lbs. from Gibraltar • of the latter a part was derived from Carniola, and a part from Spain ; 31,014 lbs. were brought from Italy. Only 192,310 lbs. were retained for home consumption in 1831. Quick silver is produced in several of the pro vinces of China. During the war, when the intercourse between Europe and America was interrupted, the price of quicksilver rose to such a height in the latter that it answered to import it from China ; but since the peace it has been regularly exported to the latter. At an average of the 14 years ending with 1828, the imports of quicksilver by the English and Americans into Canton amounted to 648,085 lbs a-year, worth 340,262 dollars. The sulphuret is found in abundance in California ; the boulders being mostly composed of native cinnabar. From the attention of the population being wholly turned on gold, these stones were ne glected, and the quicksilver necessary for amalgamating, was imported from Chinn. Besides its uses in medicine, mercury is extensively employed in the amalgama tion of the noble metals, in water-gilding, the making of vermillion, the silvering of looking-glasses, the making of baro meters and thermometers, &c.
It has been long well known that quick silver may be most readily extracted from cinnabar, by heating it in contact with quicklime. The sulphur of the cinnabar combines, by virtue of a superior affinity with the lime, to the exclusion of the quicksilver, to form sulphurets of lime and calcium, both of which being fixed lmpare, remain in the retort while the mercury is volatilized by the heat. In a few places, hammerschlag, or the iron cinder, driven off from the blooms by the tilting hammer, has been used instead of lime in the reduction of this mercurial ore, whereby sulphurous acid and sulph nret of iron are formed.
The annual production of the Bavarian Rhine provinces has been estimated at from 400 to 550 quintals ; that of Alma den, in the year 1827, was 22,000 quin tals ; and of Idria, at present, is not more than 1500 quintals. Those of Guanea Velica average 1800 quintals. All the plans hitherto prescribed for distilling the ore along with quicklime are remarkably rude. In that practised at Landsberg by Obermoschel, there is a great waste of labor, in charging the nu merous small cucurbits ; there is a great waste of fuel in the mode of heating them ; a great waste of mercury by the imperfect luting eif the retorts to the re ceivers, as well as the imperfect conden sation of the mercurial vapors ; and pro bably a considerable loss by pilfering. The modes practised at Almaden and Idria are, in the greatest degree, barbar ous; the ores being heated upon open arches, and the vapors attenicted to be condensed by inclosing them within brick or stone and mortar walls, which can never be rendered either sufficiently tight or cool.
To obviate all these inconveniences and sources of loss, the proper chemical ar rangements suited to the present improv ed state of the arts ought to be adopted, by which labor, fuel, and mercury, might all be economized to the utmost extent. The only apparatus fit to be employed is a series of cast-iron cylinder retorts, some what like those employed in the coal-gas works, but with peculiarities suited to the condensation of the mercurial vapors. Into each of these retorts, supposed to be at least one foot square in area, and 7 feet long, 6 or 7 cwts. of a mixture of the ground ore with the quicklime, may be easily introduced, from a measured heap, by means of a shovel. The specific grav ity of the cinnabar being more than six times that of water, a cubic foot of it will weigh more than 3} ewts. ; but supposing the mixture of it with quicklime (when the ore does not contain the etileareous matter itself) to be only thrice the den sity of water, then four cubic feet might be put into each of the above retorts, and still leave it cubic feet of empty space for the expansion of volume which may take place in the decomposition. The ore should be ground to a moderately fine powder, by stamps, iron cylinders, or an wheel, heel, so that, when mixed with quicklime, the cinnabar may be brought into intimate contact with its decomposer, otherwise much of it will be dissipated unproductively in fumes, for it is extreme ly volatile.
A new process for the distillation of mercury has been proposed by M. Vio lette. It consists in immersing the mass in a current of the vapor of water, heat ed from 320° to 400° cent. The vapor acts at once as the heating and the me chanical agent : it first heats the metal so as to produce distillation, and then drives before and draws over the mercurial va por just as a hot current of air promotes the evaporation of water. The steam charged with the mercurial vapor is con densed in a common refrigerator. The metal separates at the bottom of the re ceiver, while the condensed water floats above. The liquid thread which flows from the refrigerator consists of two parts ; an upper one, which is water, and the under one, the mercurial thread : there is a con tinuous current of both. No bumping occurs, the operation going on as quietly as the distillation of water. The appara tus employed consists of a cast-iron cyl indrical retort receiving the vessel which contains the mercury ; an iron worm, which, being heated, the water circulates through it, enters the retort, and traver ses it from one end to the other, the mer cury being immersed in it ; it then escapes with the mercurial vapor, and both are condensed in the refrigerator. This oper ation is simple and easy : one workman can manage an apparatus with 2000 lbs. of amalgam. There is greater economy of fuel and amalgam. In ordinary process, the latter loss is 2 per cent. ; by this there is none, and there is no danger to public health.