from the Pyrites. 307 



fuch pyrites much falc, efpecially in the fulphur, fuf- 

 ficient to dofe its metal-earth : and it cannot be 

 fhewn, that the lead ftirphur flies off without pro- 

 ducing its effect. We are not, however, to deny 

 the fait in the air its incorporating virtue, as it 

 ftands infeparably united with the humidity, tho* 

 its humidity is here 11 ill more neceffary, for exhi- 

 biting a true faline form, fuch as the vitriolic mult 

 have, feeing it is in no cafe procurable without wa- 

 ter. And though in fpontaneous vitriolifaticn the 

 humidity of the air always manifefts itfelf, yet other 

 water is not to be excluded. 



For, fir ft, the former is aided by the latter, as 

 we fee upon expofing to rain, or fprinkling with 

 water, the pyrites, either beat fmall, or in its grofs 

 ftate, and laid on large heaps together ; aided, I 

 fay, and not the former replaced by the latter, as 

 pyrites, when entirely plunged in water, and thus 

 excluded the accefs of the air, never turns to vitri- 

 cl : fo that notwithstanding the fprinkling with rain 

 and water, the whole bufinels muft chiefly turn on 

 the motion, warmth, power, and influx of the air; 

 and then alfo, by means of other water, larger and 

 purer cryftals are procured, and in a larger quan- 

 tity. But the moifxure of the air alone being em- 

 ployed, the cryftals prove fmall, like grains of fand, 

 nay, often like hairs ; and thus, when the pyrites 

 falls to pieces and to earth, there is no feparating 

 them from the impurities, without either warning 

 them with water, or without elixation and a new 

 cry (tall ifation. 



But poflibly, from the nature of the grooves, 

 the moilture of the air is not the whole, but the 

 waters, trickling down on all fides, may wafh out 

 the tender vitnol-fhoots, and coming afterwards to 



X 2 fettle 



I 



