TEEATMENT OF THE COMSTOCK OEES. 241 



ore should not be allowed to become more than half full, and no water should 

 be permitted to run over, as a sort of concentration would take place imme- 

 diately. It may happen that the trough or launder is placed unevenly, so that 

 more water runs off at one side of the discharge than at the other, and unless 

 the sample represents the whole stream its value is likely to be greater or less 

 according to the point where^it was taken. In some mills the samples are 

 taken from the ore-tanks after the sand has deposited itself in them, either col- 

 lected on the surface or drawn out from a considerable depth by means of a 

 tryer or tube. Not only may accident determine the value of such a sample, 

 but in the sand of the tanks the value of the slimes that have passed on with- 

 out depositing themselves, and which are often quite rich, is not represented. 



While making two sets of samples, the mine reserves the right to settle 

 according to the wagon sample, but in practice both assays are duly consid- 

 ered and an ecjuitable adjustment arrived at. Reclamations are not often 

 necessary. 



Milling Results. — The following tabular statements, taken from the 

 annual reports of the Savage Mining Company for years ending July 1, 1688, 

 and July 1, 1869, exhibit some of the results of milling operations. The 

 tables show the assay value of the ore, both by the wagon samples and mill 

 samples, the yield of the ore and the relation of yield to assay value, the pro- 

 portion of gold and silver, both in thfi ore and in the bullion, and, finally, the 

 total product in bullion of the quantity treated. The operations of each 

 month are shown in the statements, but the figures of the tables for any 

 single month represent the average result obtained during that month, not 

 from one but from all mills employed by the company in the reduction of 

 its third-class ore. The second-class ore treated in the last half of 1867, of 

 which the results are also given, was all worked in one mill. It should be 

 observed, concerning the comparatively lower percentage of value obtained 

 from the second-class ore, as shown in the table, that, being richer, it 

 resembles more in character the first-class ore, referred to in the commence- 

 ment of this chapter, in which the precious metals are combined with zinc, 

 lead, copper, antimony, &c., rendering the extraction of the gold and silver 

 more difficult, and unfitting it for profitable treatment by the pan process. 

 In the last year of the two referred to, no second-class ore was distinguished^ 

 31 



