724 



GEOLOGY AND MINING INDUSTRY OF LEADYILLE. 



Analyses XL ani> XLI. Mattes. 

 Elcmeniari;. 



XLI. 



Portion sohiblc in water. 



Sulphuric acid 



Protoxide of iron 



■Water 



Portion soluble in acids. 



Sulphur 



0-xygin 



Iron 



Kicliel 



Lead 



Silver 



0.037893 



0. 0.34105 



Trace 



24. 257340 

 4. 500000 



48.900300 

 None 



20. 100000 

 0. 291660 



0.030 

 0.028 

 Trace 



19. 350 

 G. 230 



40. 430 

 0.067 



31. 970 

 0.240 



Portion soluble in acids.— Cont'd. 



Gold 



Zinc 



Copper 



Arsenic 



Antimouy 



Portion insoluble in acids. 



Slag 



Loss 



Total 



Silver ounces to ton. 



0. 137000 

 0. 093811 



100.000000 j 

 85. 007 1 



0. 140 

 0.039 



100. 000 

 69. 9984 



The writer has descrihed in the EulleMu de la Soci6l6 Chiniique de Paris a peculiar niin< 

 sulphuret of nicliel and chrome-iron oxide, which certainly jiresents a great analogy with the mattes. 



ral ioimed of arsenU 



Lead and irou mattes ar..' not the only oues which form iu the furnace. A third 

 one, which is much more interesting, may be called the calcium matte. This matte is 

 formed, like its congeners, of a sulphide, sulphide of calcium, and of magnetic oxide 

 of iron, crystallographically combined. This matte has not been found in an isolated 

 state, but it exists iu combination with scoriae, and the product thus formed is pre- 

 cisely the slag of Leadville. So that the best definition of slags thai can be given is 

 the following: Slags are compounds of scoriaj or silicates and of calcium mattes, and, 

 like most of the furnace products, they are formed of chemical compounds ciystallo 

 graphically combined.' 



' Although Mr. Guyaid's ilcfiiiitiou may perhaps seem somewhat obscure to the reader, I do not 

 feel snfiicieutly fiertaiii of his meaning to attempt to modify it, and therefore leave it iu his own wnvd.i. 

 (S. F. E.) ■ 



