-VA/^^V^ 



On t)ie Theory of Mired Gases. 305 



place amongst the particles of twi> 6r more 

 gases, which will make their centres of gra- 

 vity coincide in one point ? — For the separate 

 equilibria of the fluids, which enter into the 

 constitution of the compound, will not be 

 established until this arrangement be perfectly 

 formed. The completion of this process being 

 essential to the new theory, the effect of it 

 has been, perhaps, too hastily inferred in the 

 fourth proposition of Mr. DaIton*s first essay ; 

 for I am sorry to observe, that the inference is 

 not supported by demonstration, drawn from 

 the doctrine of mechanics. It is the business 

 of the present essay to supply what has been 

 omitted, and to investigate the consequences 

 which must arise from the collision of two 

 heterogeneous gases, differing in their specific 

 gravities. 



The existence of the fluid mixture, required 

 by the theory, has been granted already, for 

 the sake of argument ; and in order to continue 

 the enquiry, it must be remarked at present, 

 that the necessary internal arrangement of the 

 compound C, is liable to be disturbed perpe- 

 petually by accidents resulting from the course 

 of things ; to which course the author of the 

 theory undoubtedly wishes to accommodate 

 his ideas. The preceding assertion may be ex- 

 emplified in a manner which is familiar, and 



