2 1 2 Analyfis of the Ah. 



preflure of the incumbent water, but alfo by 

 its coldnefs at great depths; and in what pro- 

 portion, at different known depths, and in 

 different lengths of time, that an allowance 

 may accordingly be made for it at unfatho- 

 mable depths. See Vol II. p. 332. 



This gage will alfo readily (hew the de- 

 grees of compreffion in the condcnfing en- 



gine. 



But to return to the fubjetf: of the two laft 

 Experiments, which prove the elafticity of 

 this new generated air; which elafticity is 

 fuppofed to confift in the adive aerial par- 

 ticles, repelling each other with a force, 

 which is reciprocally proportional to their 

 diftances: That illuftrious Philoibpher, Sir 

 Jjaac Newton, in accounting how air and 

 vapour is produced, Opticks %uer. 31. fays, 

 " The particles, when they are fhaken off 

 " from bodies by heat or fermentation, fo 

 " foon as they are beyond the reach of the 

 m attraction of the body receding from it, 

 « as alfo from one another, with great ftrength 

 « and keeping at a diftance, fo as fometimes 

 JJ to take up above a million of times more 

 " fpace than they did before in the form of 

 M a denfe body ; which vaft contraction and 

 f expanfion feems unintelligible, by feign- 



« ing 



