802 SILVER 



Continent, which produces for the most part ores containing but a small proportion of 

 lead, is estimated to furnish twelve times more silver than the Old. See LEAD. 



Silver has been produced in the following countries : 



Norway. The mines of Kongsberg were discovered in 1623, and they have been 

 worked, almost continuously, up to the present time, their average annual produce 

 being about 18,000 Ibs. troy. 



Hungary, Transylvania, and the Banat, are stated to produce about 92,000 Ibs. of 

 silver annually. 



Saxony and Bohemia. The mines near Freiberg are the most important. 



The Mines of the Hartz produce about 28,000 Ibs. troy of silver annually ; while 

 those of the Alps produce small quantities. 



France has no silver mines of importance. 



In Spain, the mines of Guadalcanal and Cazalla have been highly productive. The 

 total produce of the Spanish silver mines, in 20 years, was 8,200,000 Spanish ounces. 



In North America, the mines of Mexico are the most ancient, and the silver lodes 

 the most remarkable. The vein called the Veta Madre, of Guanaxuato, was often 200 

 feet in width, and that of Zacatecas is sometimes 75 feet. wide. Humboldt stated the 

 production of silver in Mexico, in 1789, to have been 7,314,344 Ibs. troy. There are 

 about sixteen silver mines producing silver ore at the present time in Mexico ; the 

 ores varying from 55 ounces to 81 ounces of silver to the ton. The Real del Monte 

 Company produced annually silver to the value of three millions and a half of dollars. 



Nevada. The discovery of silver in this region dates only from 1859 ; but the pro- 

 duction of silver and gold has been immense, often rising to nearly 300,000 tons of ore 

 per annum ; sometimes yielding silver to the value of 150 dollars per ton, and seldom 

 of less value than 28 dollars. There are numerous other districts, which space will 

 not allow us to mention. See ' The Mining and Metallurgy of Gold and Silver,' by 

 J. Arthur Phillips, for full accounts of the North American silver mines. 



South America. The silver mines are confined to the Republics of Peru, Bolivia, 

 and Chili. The mines of Cerro de Pasco are the most celebrated in Peru, the principal 

 ores being known as pacos ; these are ferruginous earths, containing varying amounts 

 of silver. These mines were discovered in 1630, and are still being worked, upon a 

 small scale. The production of silver, in Peru, has been estimated at 299,000 Ibs. troy. 



Bolivia. The mines of Potosi, which once formed a portion of the viceroyalty of 

 Buenos Ayres, are now included in. this republic. Thirty-two veins have been worked 

 in this historical mine, which was discovered in 1545, with great profit, and numerous 

 smaller ones, with more or less advantage. In the province of Potosi, according to 

 Whitney, the United States Geologist, there were, when he visited the district, 1,800 

 abandoned mines, and only 26 at work; in other parts, there were 2,365 mines aban- 

 doned, and only 40 at work. 



Chili. The most important silver mines of Chili are those in the neighbourhood of 

 Copiapo. Chlorides of silver are the most abundant ores, but there are also arsenides 

 and sulphides, the ore containing from 100 to 250 ounces of silver to the ton. Chili 

 appears to have produced in seven years 1,750,000 Ibs. of silver. 



New Granada. The Santa Anna mines, in the province of Mariquita, have been 

 long celebrated. They produced 1,266,455 ounces of silver between 1852 and 1864. 

 Since that time, the production has been limited. 



Mexican Amalgamation Process. The following description of the extraction and 

 treatment of silver ores in Mexico is derived from a paper published by Mr. J. A. 

 Phillips, who for some years acted as manager for the firm of John Taylor and Sons. 

 His excellent description may be applied to the amalgamation process, as carried out 

 in other places. 



We may previously state some of the peculiar features observable in the working of 

 the mines of Mexico, confining our attention to the mines of Guanaxuato, Zacatecas 

 (including Fresnillo), and Real del Monte. The mines of Guanaxuato are situated 

 upon one vein of great length and width. It should be understood that this vein, 

 like all mineral veins, is not productive of silver ore throughout its whole extent, but 

 the ore occurs in branches and bunches, leaving intermediate spaces of dead or unpro- 

 ductive ground ; and, as an ordinary mine-level seldom exceeds 6 feet in width, it is 

 clear that a level like this would not explore a vein of such dimensions as that of 

 Guanaxuato, while the expense of cross-cutting, as miners term it, would require more 

 capital than the owners of the mine were willing to risk, or able, in many instances, to 

 spare. Hence, there sprang up in Guanaxuato a system of working well adapted to 

 the circumstances noticed, and being based upon the principle that the hope of reward 

 acts as a stimulus to exertion, was attended with the best effects, and led to the 

 discovery of some of the richest deposits of ore. 



This system is called that of the buscones or 'seekers,' who are the working 

 miners. These men, at their own risk, work in the mines under certain restrictions ; 

 and following up such indications as may appear to them favourable, oftentimes meet 



