of the Pyrites, 26 



perly and formally it holds no fait, and if any be 

 procured, it mud be by means either of corrup- 

 tion or fermentation ; and thus, by means of the 

 deftruclion and transformation of the mixtion ; or 

 by means of a magnetifm ; and hence it is at va- 

 rious times of various forms, according to the na- 

 ture of the body it happens to be incorporated 

 withal. 



The incomprehenfibility of the volatilifation of 

 earthy particles may be objected, againft what mull 

 happen in the weatherings or deftruclion of ores 

 for new productions : but here we muft not 

 underftand an evaporation in an earthy form, as what 

 might well be allowed to happen, tho* not prove of 

 any fervice to the bufinefs of the production of 

 ores \ but an evaporation in the way of a clammy, 

 fatty, vifcous fume, wherein the moifture has in- 

 timately drank up the earthy part. There may be 

 intended in general a volatilifation, of dry par- 

 ticles, either by the power of nature or art, yet we 

 are well to obferve, that there is a wide difference 

 between undertaking fuch volatilifation with a body, 

 as (landing; in its natural crude union with other 

 things, and as feparated from them. Poppius on 

 Agricola has proved the prefence of real copper in 

 fulphur, and I myfelf have difcovered formal iron 

 in crude fulphur. Have we not here therefore a 

 volatile copper and a volatile iron ? But take and 

 try your copper and iron, and you will find fuch 

 volatilifation a very difficult matter, or not to fuc- 

 ceed at all ; whereas fuch metals, whilfl ftill lodged 

 in pyrites, volatilife without any art, barely by the 

 act of defulphuration ; and nature may carry on 

 her proceffes in fuch places, feafons, and other cir~ 

 cumftances, as are quite out of the power of art to 

 command. To come nearer to our fubjecl:, we 



. know 



