30 METALS. 



gray copper, galena, blende, pyritous copper and iron ; and the galen* 



and copper ores are argentiferous. 



The Russian mines of Kolyvan in the Altai, and of Nertchinsk in the 

 Daouria mountains, Siberia, (east of Lake Baikal,) are increasing in 

 value, and yield annually at this time, 58,000 troy pounds of silver. 

 The Daouria mines afford an argentiferous galena which is worked foi 

 its silver. It occurs in a crystalline limestone. The silver ores of the 

 Altai occur in silurian schists in the vicinity of porphyry, which con- 

 tain besides silver ores, gold, copper, and lead ores. 



In England argentiferous galena is worked for its silver. 40,000 

 tons of the ore were reduced in 1837, one half of which contained 8 to 

 8^ oz. of silver to the ton of lead, and the other half only 4 to 5 oz. ot 

 silver. 



In the United States, the Washington silver mine, in Davidson coun- 

 ty, N. Carolina, had afforded up to 1845, 30,000 dollars of silver. The 

 native silver of Prlichigan is associated with copper in trap and sand- 

 stone. These mines promise to be highly productive. 



The silver mines of the world have been estimated to yield at the 

 present time $50,000,000 annually. 



The annual product of the several countries of Europe is nearly as 

 follows : — 



Pounds troy. Pounds troy 



British Isles, 70,000 Saxony, the Hartz, and ) ,^0 000 



France, 5,000 other parts of Germany, £ * 



Austria, 90,500 Belgium, 440 



Sweden and Norway, 20,000 | Piedmont, Switzerland and ) - a nnn 

 Spain, 130,000] Russia, J" 03 ' UUU 



making in all nearly 500,000 troy pounds, or about 7,750,000 dollars 

 annually. This is small compared with the amount from America, 

 which at the beginning of the present century equaled 2,100,000 pounds, 

 or 31^- millions of dollars, nearly six times the above sum ; and it is 

 probable that these mines will again yield this amount when properly 

 worked. The annual amount from Mexico is set down at 1,750,000 

 pounds, and from Chili, Peru and Bolivia, near 700,000 pounds. The 

 whole sum from Russia, Europe and America, makes nearly 3,000,000 

 pounds troy. 



The common modes of reducing silver ores in the large way are two ; 

 by amalgamation, and by smelting. Both mercury and lead have a 

 strong affinity for silver, and these reducing processes are based on this 

 fact. In amalgamation, the silver ore is brought to the state of a chlo- 

 rid by a mixture of the powdered ore (or " schlich,") with about ten per 

 cent, of common salt ; the chiorid is reduced by means of salts or sul- 

 phurets of iron, or metallic iron in filings, and at the same time mer- 

 cury which has been added, combines with the liberated silver, and thus 

 separates it in the condition of an amalgam, (a compound of mercury 

 and silver.) The mixture of salt and "schlich" requires several days to 

 become complete. Heat is employed at the Saxon mines, but not at 

 hose of Mexico, where the climate is tropical. After the mercury is 

 ut in, (6 or 8 parts to 1 of silver,) the mixture is kept in constant agi- 



Where are the Russian mines ? What is the yield of the silver. 

 »nines of the world ? What was afforded by South America at the be- 

 inning of this century 7 Describe the process of amalgamation. 



