188 Prof. Graham on the Law of the Diffusion of Gases. 



The ratio of the times, in hydrogen and air, is not greatly 

 different at different pressures. Thus, the mercurial column 

 was depressed 18 inches, or from 29 to 11 inches. 



By air, in 7283 seconds, 



By hydrogen, in... 3025 seconds, 



*7S48 



= 2*408 = ratio of hydrogen, 



3025 ; b ' 



1 • = rate of air. 



It was found that the kind of gas in the receiver made no 

 difference on the velocity with which hydrogen entered under 

 a certain pressure. Hydrogen entered as rapidly against hy- 

 drogen in the receiver of a certain tension, as against air of the 

 same tension. Thus, 





bn£ 



3<U 



Barometer Gauge. 

 Height. 



Inches. 



15 

 14 

 13 



, 



Hydrogen entered 



against Hydrogen, 



( From preceding Table.) 



Time. 



Min. Sec. 







3 37 



3 56 



Hydrogen entered 

 against Air. 



Time. 



Min. Sec. 







3 35 



4 5 



to« it 



oltib 



:qqua 



I oJ rnuna 



riJ bus t cL 



