SOURCE OF THE ORE. 



85 



Third series of assays. — A third set of samples marked with dots and numbers 

 on the diagram was taken from the cross-drift, and the result of the assays 

 with a description of the samples is annexed. 



LIST No. 3. 



Description. 



Blue shale * 



STRATIFIED LIMESTONE. 



Grayish limestone 



Hard black limestone, with calcite and red spot 



do 



Grayish limestone 



BROKEN AND CRUSHED LIMESTONE. 



Crushed black limestone, with calcite 



Same more broken and stained 



White brecciated limestone slightly stained ... 



Same, but softer , 



Same as No. 8 



Compact calcite slightly stained 



White crushed limestone 



do 



Bluish broken limestone, with calcite 



Same more broken 



do 



Grayish, very much broken limestone 



Similar, but pulverized 



Similar, but bluish 



Yellow and reddish soft broken limestone 



Bluish, somewhat broken 



Same more broken 



do 



Muish stained limestone 



Same more broken and stained 



Hard white sparry stained limestone 



Soft yellowish broken limestone 



Soft, taken near No. 14 of List No. 2 



value! Averages. 



51 ! 



1-1 



i::j 



Discussion of assays. — None of the specimens of limestone assayed contained 

 any ore, at least none that was perceptible to the eye, and they had the 

 appearance of the ordinary limestone found in the mineral belt. The 

 assays, which were made with great care in the manner described in Chap- 

 ter XT., prove: First, that the country rock near the ore bodies is richer in 

 silver than that at some distance from them; second, that the least changed 

 and metamorphosed limestone is the poorest; and, last, that the most 

 crushed and broken limestone, and that which is somewhat stained with 



