GASES IN THE.ATMOSPHERE, 



437 



t. Table of the Weights of the different Gafes conjtUuting the 



JtmOfphere. 



Inth of Mercury. 



Azotic gas - - - - - 23.36 Abfoluteweights 



„ z^ 1 Q of the different 



Oxygenous gas ... - 6.18 . gafes in the 



Aqueous vapour » » - - A'ir whole atmo- 



Carbonic acid gas - - - - .0^ ^ fp^"<=- 



30.06 



it. Table of the proportional Weights of the different Gases in d 

 givm Volume of Atmofpheric Air, taken at the Surface of the 



Earth, 



Azotic gas - 

 Oxygenous gas 

 Aqueous vapour 

 Carbonic acid gas 



per cent. 



- 75.55 



- 23.32 



1.03* 



- -.10 



100.00 



Weights of the 

 different gafes 

 in equal bulks 

 at the earth's 

 lurface. 



Ill, On the Proportion of Gases at different Elevations. 

 M. Berthollet feems to think that the lower ftrata of the at- Coitiputatloii of 

 mofphere ought to contain more oxygen than the upper, ^^- q^ a^i^s »\ioys. 

 caufe of the greater fpecific gravity of oxygenous gas, and the eartli's fur- 

 the flight affinity of the two gases for each other* (See Anna), j^"* ^^^ notablr 

 de Chiraie, Tom. 34. page 85.) As I am unable to conceive different at any 

 even the poffibility of two gafes being held together by affi- acceflibleheight. 

 nity, unlefs their particles unite fo as to form one centre of re- 

 pulfion out of two or more (in which cafe they become one 

 gas) I cannot fee why rarefadion fliould either decreafe or in- 

 creafe this fuppofed affinity. I have little doubt, however, a^ 

 to the fadl of oxygenous gas obferving a dimini thing ratio in 

 afcending ; for, the atmofpheres being independent on each 

 other, their denfities at different heights mufl be regulated by 

 their fpecific gravities. Hence, if we take the azotic atmo- 



' • The proportion of aqueous vapour muft be underftood to be 

 variable for any one place : the others are permanent or nearly foi 

 Vol, XIII. — Supplement. Hh fphere 



