606 MIOTNG INDUSTEY. 



SECTION II. 

 TEEATMENT OF THE OEES. 



There are two principal metliods by wMcli the ores of this district are 

 treated. One consists in smelting; the other in amalgamation. The first 

 is applied only to ore that is rich in lead, containing not less than 30 per 

 cent, galena, and moderately free from zincblende and gangue. The second 

 is employed for the ores as they more frequently occur, containing a mixture 

 of galena, blende, pyrites, silver sulphurets, and gangue, in variable propor- 

 tions. The second class is much more abundant than the first, as it is only 

 a small proportion of selected ore that contains the requisite percentage of 

 lead; and much' of that which is smelted requires a previous concentration in 

 order to separate the excess of gangue, blende, &c., from that which is suit- 

 able for the smelting furnace. 



There are, in Gleorgetown and its vicinity, two establishments for the 

 treatment of ores by smelting, one being known as the Georgetown Smelt- 

 ing Works, formerly under the management of Mr. J. T. Herrick, and lately 

 standing idle ; the other, located at the Brown mine, and belonging to the 

 Brown Mining Company, as already noticed; three establishments for work- 

 ing ores by amalgamation, the first being that of Messrs. Huepeden & Com- 

 pany, the second that of Mr. J. 0. Stewart, and the third that of the Baker 

 Mountain Mining Company. There are also two establishments, lately 

 erected, for the concentration of ganguey ores ; one proposing to accomplish 

 the object by dry, the other by wet processes. Besides these are the works 

 of Mr. Dibbin, at Argentine, already noticed, and several smaller concerns, 

 chiefly experimental in their character. 



Smelting Works. — The smelting process employed in the first two of 

 the above-named establishments is one of the oldest and best known of all 

 methods for the extraction of silver from its ores, and is described with much 

 detail in various metallurgical works. Its purpose is to smelt argentiferous 

 galena, or other argentiferous substances with lead ores, in order to produce 

 metallic lead in which all, or nearly all, the silver is then contained, and from 

 which it may be separated by cupellation. The details of this process consist 



