284 Analyfis of the Air. 



falphur in its Analyfis is found to contain 

 an inflammable oil, an acid Salt, a very fixt 

 earth, and a little metal. 



Now fulphur and air are fuppofed to be 

 adted by that ethereal medium, " by which 

 " (the great Sir Ifaac Newton fuppofes) 

 " light is refraded and reflected, and by 

 " whofe vibrations light communicates heat 

 " to bodies, and is put into firs of eafie 

 " reflexion, and eafie tranfmiffion : And 

 " do not the vibrations of this medium 

 " in hot bodies contribute to the intenfe- 

 " nefs and duration of their heat? And do 

 " not hot bodies communicate their heat 

 " to contiguous cold ones, by the vibra- 

 ^ tions of this medium, propagated from 

 " them into cold ones? And is not this 

 " medium exceedingly more rare and fub- 

 * c tie than the air , and exceedingly more 

 " elaftick and aftive > And does it not rea- 

 c£ dily pervade all bodies, Optick qu. 18. 

 " The elaftick force of this medium, in 

 " proportion to its denfity, muft be above 

 " 490,000,000,000 times greater than the 

 " elaftiqk force of the air is, in propor- 

 "' tion to iti§ ;4 e Afity, ibid. qu. 21." A force 

 sufficient to' give "an intenfe degree of heat 3 

 ? ^ ; efpecially 



