of the Pyrites; gj^ 



pears from the volatile falts procured from the cor- 

 rupted parts of animals, and the acid of beer. This 

 deftruction is in the vegetable kingdom called fer~ 

 mentation ; in the animal, corruption ; and, in the 

 mineral, I find no better term to exprefs it by than 

 : hiring , o r d iffo ! u t i on . 



The matters confidered as exhaling, are either 

 purely watry, as pure water and brandy ; or watry- 

 earthy; as wine, beer, vinegar, oil, and (limy, 

 faline, and bituminous waters; or earthy- watry, as 

 wood, bones, gums, falts, fulphur, bitumen; or 

 laftly, almoft pure earth, if not entirely earthy, as 

 crude and metallic earths, Hones, ores and me- 

 tals. 



Now, as evaporation is a kind of motion* and 

 motion implies an impulfe ; we here find as impel- 

 lents, air and fire, which mult animate, as it were* 

 and make natural mixt bodies evaporate, or they 

 would otherwife remain at reft and motionlefs. Air 

 certainly is a capital inftrument in the bufinefs of 

 evaporation, as being of itfelf not only fufficient, 

 but better fitted for the purpofe without actual fire ; 

 whereas fire cannot fubfift without air : and the dif- 

 folutions, malaxations, feparations purifications, 

 and new productions, &c. by means of air alone, 

 prove quite different from, thofe procured by fire. 

 Yet air, which is in itfelf cold, and neither at all 

 times attempered by the fun, nor by a particular fore 

 of weather and wind, may be aided in its effects, 

 when you would have it a proper, efficacious inftru- 

 ment, if not by an actual fire, yet by a due fcreen- 

 ing. The air operates from within outwards, 

 whereas actual fire only externally : air alfo takes 

 up more time, and thus makes purer and more 

 lading parts. It, indeed, carries along with it foreign 



S 2 matters. 



