PROCESS OF GASSIFICATION. 197 



Spain, obtained precisely the same materials, 

 and ascertained, that the atmosphere uniformly 

 preserved the same composition, whether with 

 regard to temperature to pressure, as indi- 

 cated by the barometer to winds to humi- 

 dity to the season of the year, or hour of the 

 day and night. GAY-LUSAC proved, by direct 

 experiment, that the different strata of the at- 

 mosphere, contain the same gases, in the same 

 relative proportion. He filled a glass balloon, 

 at the elevation of 2173, and it was found to 

 contain, of oxygen 21-49 in 1000 parts; the 

 remainder was nitrogen. The atmosphere at 

 the surface, was analysed also at the same time, 

 in the eudiometer. The ABBE FONTANA, who 

 jnade a number of accurate experiments on the 

 quality of the atmosphere, in different situa- 

 tions, says, that he found the air of one coun- 

 try, and that of another, much more alike than 

 is generally believed. At Paris, he examined 

 the air of different places, at the same time, and 

 more especially of those places, in which it was 

 most probable to meet with infected air, be* 

 cause those places abounded with putrid and 

 impure exhalations ; but the difference did not 

 amount to one fiftieth of the whole. Having 

 taken the air from the top of a mountain, 

 near Paris, at the height of five hundred 

 feet from the plain, and compared it with the 

 air of Paris, taken at the same time ; after 



