274 



MINING INDUSTRY. 



velop the presence of blende, galena, and argentite ; more rarely, polybasite 

 and stephanite. 



Samples of finely crushed ores were subjected to a microscopical exami- 

 nation. The following minerals were observed: quartz, small cubes and par- 

 ticles of iron and copper pyrites, flakes of blende, and thin pieces of a dark 

 lead-gray mineral, which were determined to be argentite. 



In order to determine the chemical and mineralogical composition of the 

 ore more accurately, samples of carefully chosen first and third-class rock were 

 subjected to a thorough analysis. The first-class came from the Savage mine, 

 and was taken from a lot of ore that had been crushed at Ball's mill. Its 

 assay value was $489 22. The third-class ore came from the Kentuck mine ; 

 it was obtained at the mill from the troughs immediately after leaving the bat- 

 teries, in the same manner as the mill samples are ordinarily taken. The ma- 

 terial used was selected from 300 or 400 pounds of crushed rock, collected at 

 intervals during a day's run of tv^^enty-four hours. Its assay value was $43 74. 



The results of both analyses were as follows : No. 1, Savage ore ;^ No. 

 2, Kentuck ore: 



Silica ...... 



Alumina 



Protoxide of iron . 

 Protoxide of manganese 

 Lime ...... 



Magnesia . . . . . 



Potash and soda . . . 

 Sulphide of zinc . 

 Sulphide of lead . . . 

 Sulphide of silver . . . 

 Subsulphide of copper . 



Gold 



Bisulphide of iron 

 Moisture 



No. I. 



83.95 

 1.25 



1.95 



.64 



.85 



2.82 



1.28 



1.75 



•36 



1.08 



.30 



.02 



1.80 



2.33 



100.38 



No. 2. 



91.49 



1. 13 



.83 



1.42 



1.37 

 1.05 



.13 



.02 



.12 



.41 



.0017 



.92 



•59 



99.48 



1 The writer is indebted to Mr. WiUiam G. Mixter for tlie analysis of the sample from 

 the Savage mine. 



I 



