270 Of the Principles 



know the principles of the pyrites to as tolerable a 

 degree of certainty as is pofiible, but to pretend to 

 fhew them in glais-bodies or cucurbits, and thus 

 refolve the pyrites into thefe principles, and make 

 them the objects of our fenfes, is what I defpair 

 of ever doing. 



I am, however, apt to think, my notions about 

 the original particles of pyrites and ores in general, 

 may go as far, if not farther than thofe other prin- 

 ciples ; namely, fait, fulphur, and mercury, aether, 

 and air, globules and/n>, or acid and alcali, i£c. 

 As to running mercury, tho J no metallic principle, 

 yet I believe it procurable from pyrites. Mr. Boyle 

 tells us, that fome choice Englim marcafites being 

 worked, in order to alTay them for gold and filver, 

 did, without any mercurial addition^ yield fome 

 mercury *. This may well be matter of furprize, 

 as it may be what does not always happen : but, 

 when I come to confider arfenic, as a fubftance 

 certainly mercurial, and that it only wants to be 

 made fluid, I fee nothing uncommon in all this. I 

 jfhall fay nothing of the acid fait of fulphur, as what, 

 among all the volatile things, comes the neareft to 

 quickfilver. 



We have alfo experiments of fome mercury be- 

 ing procured from oil of vitriol. Now arfenic 

 lodges in almoft all pyrites ; in a large quantity in 

 the white •, in a lefs proportion always in the yel- 

 low, and often in the yellowifh. _ Probably, the 

 above marcafites were yellowifh, as the yellow do 

 not fo readily appear marcafitical, that is, cubical; 

 and the white, tho' fuch a figure be not uncommon 

 to them, are not commonly called marcafites. And. 

 probably, the yellow and white may be fitted for 



mercu- 



* Boyle on the producibility of the chymical principles. 



