8 ON MIXED GASES. 



Examination of hastily inferred in the fourth proposition of Mr. Dalton's first 



Mr. Dalton's ggsav ; for I am sorry to observe, that the inference is not 

 theory of mix- -^ ' • , r i i 



ed gases. saipported by demonstration, drawn from the doctrine of me- 



chanics. 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 inquiry, it must be remarked at 

 present, that the necessary internal arrangement of the com- 

 pound C, is liable to be disturbed perpetually by accidents 

 resulting from the course of things ; to which course the author 

 of the tiieory undoubtedly wishes to accommodate his ideas. ' 

 The preceding assertion may be exemplified in a manner 

 which is familiar, and may be applied with ease to natural 

 phenomena : let us suppose then an additional quantity of the 

 gas A to be thrown into the pneumatic apparatus, containing 

 the compound C, which was in a state of proper adjustment 

 previous to this event. No one will imagine, that this fresh 

 matter can diffuse itself through the mass of C with the same 

 expedition that the electric fluid shews in expanding along a 

 conductor: this sirpposition is contradicted by various appear- 

 ances, from which the following one is selected ; agitation is 

 known to accelerate the union ofoxigen and nitrous gas. The 

 quantity of A then, which has been newly admitted, will re- 

 main at first unmixed with B ; but it will act immediately with 

 a repulsive force upon kindred particles diffused through the 

 compound C. This new modification of A will not preserve 

 the den«;ity of its parts everywhere in a constant ratio, to the 

 density of the corresponding parts of B ; and this change will 

 disjoin the centres of gravity of A and B ; which has been 

 proved above. But when these points are placed apart, the 

 separate equilibria of the fluids cease to exist, which has also 

 been demonstrated before ; therefore A and B begin to act and 

 react mutually; which circumstance disturbs the necessary 

 ndjustment of C, and forces it to assume another' character. 

 It has aho been proved in a former paragraph, that the two 

 fluids will act upon each other in the manner of elastic bodies, 

 even when the heterogeneous particles are supposed to-be mu- 

 tually inelastic j consequently A and B will begin to obey the 



