Analyjis of the Axr. 177 



twenty feconds more, which it does not ; 

 therefore the burning of the candle is not 

 wholly owing to the vilifying fpirit, but to 

 certain degrees of the air's elafticity. When 

 a wholly exhaufted receiver was by means of 

 a burning-glafs firft filled with the fumes of 

 brown paper with Nitre, and then filled 

 with frefh air, the nitrous paper, upon ap- 

 plying the burning-glafs, did freely detonize; 

 and a Candle put into a like air, burnt for 28"$ 

 which in a frefh air, in the fame receiver 

 burnt but 43 ; but when the fame receiver, 

 with air in ir, was filled full of fumes of 

 detonized Nitre, and a Candle placed in that 

 thick vapour, it went out inftanrly ; for a 

 Candle will not burn, nor the Nitre deto- 

 nize in a very rare, nor a very thick air ; 

 whence the reafon why the Nitre detonized, 

 and the Candle burnt, when placed in the 

 receiver, afcer frefli air was let in upon 

 the fumes which were made in vacuo, was, 

 that thofe fumes w r ere much difperfed and 

 condenfed on the fides of the glafs, upon 

 the milling in of the frefh air: for the fumes 

 were then much more rare and tranfparent, 

 than before the air was let in. 



That a Fire which is fupplied with a hot 

 air will not burn fo briskly as a Fire which 



T 3 is 



