36 The feveral SPECIES 



treating the pyrites itfelf; the ore-fmelter having 

 his fi one pyrites ; the fulphur- matter, his fulfhur- 

 pyrites ; the vitriol-boiler, his vitriol-pyrites, &c. 

 tho' they all mean one and the fame thing : for 

 the fuJphur-pyrit* both yield a good crude-Jione, and 

 are alio proper for making vitriol. 



The appellations, borrowed from the iron and 

 copper, diftinguilh the metallic contents, and con- 

 fequently the grand principles of their refpeclive 

 minerals ; but may be apt to miflead, as im- 

 plying iron not to be the ground-earth of all the 

 pyrites -, and excluding the other principles, viz. 

 the fulphur and arfenic, which are quite loll: in 

 thefe appellations. The external figures do ce'r- 

 tainly denote fomething peculiar, which the 

 colour may net : for from my own experience of 

 various pyrit*e> I may boldly affirm a fpherical fort 

 always to contain pure iron and fulphur without 

 any the leail: copper or arfenic ; yet hence it follows 

 not, that the angular pyrit* always hold copper, 

 feeing they partake of iron equally with the round ; 

 nor can we always diftinguifh whether a fample 

 under examination be a part of a round or a half- 

 round pyrites, which laft holds copper confidcrably, 

 or at leaft is not unmixed with arfenical parts. 

 Confequently, fo far as 1 have hitherto confjdered 

 the matter, I find myfelf obliged to drop the figures 

 and adhere to the colours, as affording the moil 

 proper divifion of the pyr'ncs, and better denoting 

 their internal properties, which the figures rarely 

 do; the white pyrita undoubtedly containing arfenic, 

 the yellowilli, fulphur, the yellow, copper. And 

 a perfon much converfant in ores, will, upon fight, 

 be capable to pronounce, whether the former con- 

 fid of pure iron, or, of copper too, and the pro- 

 portion of each •, the bufinefs in this cafe reiting 

 on the various degrees of one and the fame colour, 

 not to be defcribed by words, but learned by a 



repeat- 



