Elements of Mineralogy. 



contains alfo regulus of antimony, 

 and, according to Mr. Bergman, it contains 

 24 per cent, of copper, and 5 of filver ; but 

 this belongs to the next Species. 



SPECIES X. 



Mineralized by Arfenic and Sulphur -, with Cof- 

 fer ', Iron, and Regulus of Antimony. 



Brown Silver Ore, Leber erz. 



24. Its colour is moflly of a reddifh brown, 

 fometimes dark grey, fometimes it is found 

 cryftalized in pyramids, but moftly amor- 

 phous j when fcraped it appears red > it con- 

 tains from i to 5 per cent, of filver ; the 

 greateft part is copper, and the next in pro- 

 portion is arfenic. 



It is found in Sweden, Germany and Spain. 



25. It is analyfed by boiling it in about 6 

 times its weight of dilute nitrous acid, which 

 will take up the filver and copper, and leave 

 the regulus of antimony and arfenic : thefe 

 being boiled in ftrong nitrous acid are de- 

 phlogifticated, and the arfenic becomes foluble 

 in water ; the c<*lx of antimony remains un- 

 diflblved ; the fulphur may be found in a 

 fecond experiment, ufmg aqua regia inftead 



of 



