Anatyfis of the Air. up 



fumes Were at the fame time deftroying the 

 elafticity of the air. I took care to make 

 the air in both tubes of the fame tempera- 

 ture, by firft immerfing them in coid water, 

 before I comprefTed them. 



Experiment C VI. 



I fet a lighted tallow Candle, which was 

 about to of an inch diameter, under the in- 

 verted receiver z z a a, ( Pig. 35.) and with 

 a fyphon I immediately drew the water up 

 to z z : Then drawing out the fyphon, the 

 water would defcend for a quarter of a mi- 

 nute, and after that afcend, notwithftand- 

 ingthe Candle continued burning, and heat- 

 ing the air for near 3 minutes. It was ob° 

 fervable in this Experiment, that the fur- 

 face of the water z z did not afcend with 

 an equal progreflion, but would be fome- 

 times ftationary 5 and it would fometim.es 

 move with a flow, and fometimes with an 

 accelerated motion 5 but the denfer the fumes 

 the fafter it afcended. As foon as the Can- 

 dle was out, I marked the height of the 

 water above z z, which difference was e- 

 qual to the quantity of air* whofe elaf- 



(^ % ticity 



