126 Of the CopPER*£fc. 



as in many other ores, fo alfo is it to be met with in 

 the pyrites •, and which, both in refpedt of quality 

 and quantity, may ferve occafionally to heighten, or 

 to lower the colours of ores. 



This third, together with either a defect of 

 fulphur, or a plenty of arfenic, may be a concurring 

 caufe, Why the often mentioned rich copper-ore of 

 Hohenftein, has acquired fo very pale an appearance, 

 that were it not for its uncommon denfity and clofe- 

 nefs, it might eafily be taken for a yellowifh pyri» 

 tes, or for what it really is not. In fuch circum- 

 ftances, we muft be upon our guard in judging 

 of the pyrites by their colours, at leaft we muft not 

 fuffer ou delves to be milled by the pale -, though in 

 fuch things, where many circumftances muft pften 

 be considered together, colours afford the greateftv 

 light, as was observed above, chap. II. 



Laftly, I muft add, that in the white pyrites 

 there is no copper at all. Now, whether any, or 

 how much copper, there may be in kupffer nickel, 

 a fort of cobald, of a copper '-red \ and allied to the 

 vfhittfyriteS) is a thing that muft beprevioufly en- 

 quired into. 



C HAP 



