28 x Analyjis of the Air. 



of the acid fulphureous particles of the fuel, 

 and the elaftick ones, which arife and enter 

 the Fire, either from the fuel in which they 

 abound, or from the circumambient air : For 

 by Experiment 103, and many others, acid 

 fulphureous particles adl vigoroufly on air ; 

 and fince a&ion and re-a&ion are reciprocal, 

 fo muft air on fulphur ; and there is, we fee, 

 plenty of both, as well in mineral as vege- 

 table fuel, as alfo in animal fubftances, for 

 which reafon they will burn. 



But when the acid fulphur, which we fee 

 afts vigoroufly on air, is taken out of any 

 fuel, the remaining Salt, water and earth, are 

 not inflammable, but on the contrary, quench 

 and retard fire; and as air cannot produce 

 fire without fulphur, fo neither can fulphur 

 burn without air : Thus Charcoal heated to 

 an intenfe degree for many hours in a clofe 

 veflel, will not burn as in the open air 5 it 

 will only be red-hot all the time, like a mafs 

 of Gold, without wafting : But no fooner is 

 it expofed to the free air, but the fulphur, 

 by the violent aftion and re-a&ion between 

 that and the elaftick air, is foon feparated and 

 carried off from the Salt and Earth, which 

 are thereby reduced from a folid and hard, to 

 a foft impalpable Calx. 



And 



