76 Mr. Graham's Experimental Researches 



was found in the receiver, of which the capacity = 150 



parts — of 



Hydrogen gas (sp. gr. 0.0694*) . . 8.3 parts. 



Carburetted hydrogen of marshes (sp. gr. 0.5555") . 56 

 Ammoniacal gas (sp.gr. 0.59027') . . 61 



defiant gas (sp. gr. 0.9722') . . .77.5 



Carbonic acid (sp. gr. 1.52 7 7 # ) . . .79.5 



Sulphurous acid (sp. gr. 2.2222') . . 81 



Chlorine (sp.gr. 2.5) ... . 91 



(2). After diffusion for four hours through tube I — in 152 

 parts there was found — of 



Hydrogen gas . . . ,28,1 

 Carburetted hydrogen . . 86 

 Ammoniacal gas . . .89 

 defiant gas . . , 99 



Carbonic acid . . . . 1 04 

 Sulphurous acid . . . 110 

 Chlorine 116 



There have, therefore, left the receiver in the same time — of 



Hydrogen gas . . . 1 23 . 9 parts. 



Carburetted hydrogen . . .66 



Ammoniacal gas . . . 63 



defiant gas . . . .53 



Carbonic acid gas . • . 48 



Sulphurous acid . . .42 



Chlorine .... 36 



In deducing the comparative diffusiveness of the different 

 gases from the table above, it is necessary to keep in mind the 

 diminishing rate, according to which the latter portions of the 

 gas leave the receiver. It was determined, with precision, in 

 the case of olefiant gas, that that gas continues to leave a 

 receiver, by diffusion, according to the same diminishing rate 

 which holds in mechanical exhaustion by the air-pump. 

 Hence the initial diffusions of the gases are even more varied 

 than the numbers of the table. As much hydrogen gas left a 

 receiver in two hours, as of carbonic acid in 10 hours, Hence 

 the former gas is five times more diffusive than the latter. In 

 all cases the gases were necessitated to diffuse in opposition to 

 the solicitation of gravity. Yet carburetted hydrogen and 

 ammoniacal gases left the receiver in greater proportions than 



