et 



312, Analyfis of the Air. 



" the ftronger and more lucid colours—— 

 u and be more and more difficultly diverted. 

 Qu. 29. So Qu, 30, heobfervcsof air, that 

 " denfe bodies by fermentation rarify into 

 " feveral forts of air, and this air, by fer- 

 e< mentation, and fometimes without, returns 

 " into denfe bodies." And fince we find 

 in fact from thefe Experiments, that air a- 

 xifes from a great variety of denfe bodies, 

 both by fire and fermentation, it is probable 

 that they may have very different degrees of 

 elafticity, in proportion to the different fize 

 and denfity of its particles, and the different 

 force with which they were thrown off in- 

 to an elaftick (late. " Thofe particles ( as 

 <c Sir Isaac Newton obferves) receding 

 " from one another, with the greateft re- 

 " pulfive force, and being moft difficultly 

 tc brought together, which upon contact 

 cc cohere moft ftrongly." Whence thofe of 

 the weakeft elafticity, will be leaft able to 

 refift a counter-acting power, and will there- 

 fore be fooneft changed from an elaftick 

 to a fixt ftate. And *tis confonant to reafon 

 to think, that the air may confift of infinite 

 degrees of thefe, from the moft elaftick and 

 repelling, till we come to the more flnggi/h, 



watry 



