tn the P y R i t e s. 2J9 



fome of thefe, particularly cementation, may have 

 fome effect as to the encreafe of the gold. 



To educe the gold out of the pyrites by aqua regis, 

 feems to be an uncertain method, as the gold is 

 generally entangled, not only in much foreign ad- 

 mixture, but in fuch metals, as copper and iron, 

 on which aqua regis equally works as on gold-, yet 

 this I have alfo done, and, after incoffiGn, copelled 

 the precipitated mafs, but without any effect : 

 nay, if by the former method I procured any thing, 

 by the latter, on the contrary, I have rarely fuc- 

 ceeded at all, or in a far lets quantity. 



In pure fulphur -iron-pyrites there is not the leafl 

 gold, a thing well to be obferved, even fhould it 

 happen to be the miner a martis Jolaris Hajfiaca itfelf, 

 the fulphur of which, for its high purity, is greatly 

 to be valued (but its vitriol mufl yield to a facti- 

 tious, pure iron-vitriol, but much more to a vi- 

 triol from calamy, alfo to the green, foffile, Hun- 

 garian vitriol) but its gold is only imaginary : 

 much the fame holds of thofe iron-pyrites which 

 are but very little coppery, as alfo of moil pyrites 

 in nature. Among thefe there is now and then 

 a proof, where the mark of filver holds about 

 one quarter, or one half, or one heller * of 

 gold -, but when the centner or quintal of ore gives 

 forth one, one half, nay, only one quarter of a 

 drachm of filver, and you come to calculate the 

 number of centners of fuch ore, neceffary for the 

 eduction of a mark of filver, the gold to a centner 

 muff be very inconfiderable, nay, not to be calcu- 

 lated, much lefs be vifible, or be manifefted by 

 the moll tender, fenfible fcales -, can it then be 

 thought worth while to mention gold in this cafe ? 



But 



* Seven hellers make a penny weight, thirty-two hellers a 

 loth, or half ounce. 



