popper. 



ponfifts of 2 parts pounded glafs, i of cal* 

 cined borax, and 4- of charcoal : if the ore 

 be poor more borax may be added ; black 

 flux is hurtful, as it forms an hepar which 

 holds part of the copper in fqlution. Mem, 



far- 1775- 



29. Mr. Margraaf, in the Memoirs of 

 Berlin for 1775* recommends a mixture of 

 equal parts of clay well warned, fluor, and 

 lime-ftone, and \ part of charcoal, with an 

 equal weight of the torrefied ore ; the whole 

 to be melted in a porcelain heat. The coal 

 he ufes is that left after the diftillatiqn of 

 tartar. 



SPECIES VIII. 



Mineralized by Sulphur and Arfenic, with Zinc 

 and Iron. 



Blendofc Copper Ore. 



30. Mr. Monnet fays he has met with this ore 

 oply at Catharine berg in Bohemia ; Jt is of a 

 brown colour, of a hard, folid, and compact 

 granular texture ; it contains from 1 8 to 3 

 per cent, of copper. 



31. It is analyfed in the liquid way by fo- 

 lution in nitrous acid and precipitation of the 

 popper by iron : the iron and zinc are preci- 

 pitated 



