COMPOSITION OF THE ATMOSPHERE. 



83 



In the day the carhonic acid at Chambeisy is 0*0445, 

 and at night 0*0402 ; in Geneva during day 0*0485, and 

 at night o*04i4. The difference for the country is 0*0043, 

 and for the town 0*0073. The diminution at night is 

 greater in the town, where less fuel is burnt and people are 

 shut up. 



One of the most curious results of De Saussure's inquiry 

 is, that the carbonic acid on the mountains is actually 

 greater than on the plains. It wiU be interesting to give 

 these figures, as they are often referred to, and seldom 

 seen. It may be remembered here that there was some 

 reason to believe in a diminution of oxygen in mountain 

 air to a minute extent. The increase of carbonic acid is a 

 corroboration. 



Name of mountain. 



Height of 

 mountain 

 in metres. 



Carbonic 

 acid in the 



air of the 

 mountain. 



Carbonic 



acid in the 



air of the 



plain. 



La Dole 



1267 

 877 

 331 



1267 

 908 



945 

 963 

 963 



•0461 

 ■0557 

 •0544 

 •0491 

 •0481 



■0413 



■0443 

 •0454 

 •0369 

 •0360 

 •0422 

 '0395 



•0474 

 •0482 

 •0482 

 •0446 

 •0446 

 1*0367* 

 l*o359t 

 •0414 

 •0415 

 •0387 

 •0322 

 ■0355 

 •0315 



Grand Saleve-sur-Crevin 



Hermitage (Petit Saleve) 



La Dole 



Vasserode-sous-la-D61e 



Grand Saleve-sur-Grange- 1 



Tournier J 



Col de la Faucille 



ditto 



ditto 



ditto 





ditto , 



ditto 











He refers the difference to the rain below, and the 

 moisture of the ground, and to vegetation, which dimi- 

 nishes the carbonic acid and increases the oxygen. He 

 finds also that the mountain air does not change at night 

 as the air below does. He finds a minute increase of car- 

 bonic acid arising from violent winds, and thinks this may 

 arise from the upper mixing with the lower strata ; his 

 evidence on this point may be explained by the fact that 



* At foot. t At Chambeisy. 



SER. III. VOL. III. D 



