261: 6n the Tendency of 



THIRD CLASS. 



with Oxygenous Gas, uitmospheric Air, Hy- 

 drogenous and Azotic Gases. 



The results of the preceding experiments 

 upon gases that have no known affinity for 

 each other, were conformable to what h priori, 

 I had conceived ; for, according to my hy- 

 pothesis, every gas diffuses itself equably 

 through any given space that may be assigned 

 to it, and no other gas being in its way can 

 prevent^ though it may considerably retard this 

 diffusion. But in some of the following ex- 

 periments, in which the two gases are knov^n 

 to have a chemical affinity for each other, I 

 expected different results from what were 

 found; perhaps without ' sufficient reason. 

 For, chemical union cannot take place till the 

 particles are brought into contiguity ; and the 

 elastic force which sets them in motion ap- 

 pears, from the above experiments, to be a 

 principle diametrically opposite to affinity.— 

 That circulation of elastic fluids, therefore, 

 which we have now before us, cannot be acr 

 celerated by their having a chemical affinity 

 for each other. Another circumstance deserves 



