3 66 Elements of Mineralogy* 



SPECIES VII. 



Mineralized by Sulphur and Arfenic^ with <% 

 little Iron. 



Arfenical OK grey Copper Ore. Kupfer, Jahl 

 ertz, Weifs kupfer ertz. 



2,6. This is of a white, grey, or brown 

 colour; it is moderately hard, and very 

 brittle, fometimes cryftalized, and 1 often of 

 a 4 n indeterminate figure; it is of very diffi- 

 cult fufion, and heavier than the preceding. 



27. It contains from 35 to 60 per cent, of 

 copper 5 the brown is the richeft in copper ;. 

 the white or grey contains moft arfenic; it 

 frequently contains filver, and if this exceeds 

 3 or 2 per cent. it; is called greyjili)er 



It is found imbodied in all forts of ftones* 

 and mixed with other copper ores as \yell as. 

 with the ores of other metals* 



28. The analyfis of thefeore-s in the moift 

 way may be underftood from what has been 

 already faid. To effay them in the dry way, 

 they ihould firft be pulverized and feparated 

 as much as poflible from ftony and earthy 

 particles, then roafted to feparate the fulphur 

 and arfenic, then melted with a mixture of an 

 equal weight of Mr. Tilled flux, which 



confifta, 



