-CHAPTER XIX. 



DECOMPOSITION OF ATMOSPHERIC 

 MATTER, ANP THE FORMATION OF 

 RAIN, ETC. 



HOPING that I have been a fkilhful historian of 

 the phenomena which I have described, and 

 that I have succeeded in tracing, (as far as the 

 narrow span within which my abilities are con- 

 fined will admit,) those phenomena to their pro- 

 ducing causes ; it only remains that I should 

 point out the progressive changes which the at* 

 mosphere undergoes, when the parts, which 

 are converted from a liquid to a vaporific, and 

 gaseous state, are made to return back from a 

 gaseous to a vaporific, and, finally, to a liquid 

 one ; these causes may be principally referred 

 to combustion, to the absence of the solar 

 rays, to the changes of day and of night ; and 

 to the different seasons of the year. And final- 

 ly, to whatever cause by which the expansi- 

 bility of the atmosphere is weakened or des- 

 troyed. 



This loss of expansibility which the air 

 c c 



