lO-l Prof. Clausius on the Conduction of 



culcs of the composition CI H, the proposition at which we have 

 just arrived would lead lis to believe that each atom of hydrogen 

 docs not remain quietly in juxtaposition with the atom of chlo- 

 rine with which it first united, but, on the contrary, is constantly 

 changing places with other atoms of hydrogen, or, what is the 

 same thing, changing chlorine." 



According to this, Williamson appears to assume even a 

 greater mutability in the grouping of the partial molecules than 

 is necessary for the explanation of the conduction of electricity. 

 He speaks of constant changes of place between one atom of hy- 

 drogen and other hydrogen atoms, whereas, in order to explain 

 electi'ic conduction, it is sufficient if the impact between complete 

 molecules is occasionally, and perhaps, comparatively speaking, 

 rarely accompanied by an interchange of partial molecules. 



In confirmation of his views, WilUamson adduces the deport- 

 ment of a liquid in which two compounds consisting of diff'erent 

 electro-positive and different electro-negative constituents are 

 dissolved : in such a case, the two original compounds do not 

 simply continue to exist, neither does another arrangement ensue 

 in which an electro-positive constituent is exclusively combined 

 with one of the two electro-negative constituents, and vice versa; 

 on the contrary, all the four possible combinations occur in 

 certain proportions, whence it happens that when one of the four 

 combinations is insoluble, the same becomes precipitated. I 

 also think that this deportment receives a very natural explana- 

 tion from the assumption, that the combinations of each pair of 

 partial molecules, instead of being fixed, are mutable, and that 

 a positive partial molecule may not only displace another of the 

 same kind, but also a positive partial molecule of a diff'erent 

 kind ; in the exposition of the foregoing theory, this deportment 

 has been kept in view. Nevertheless, here also I regard it as 

 unnecessary that all molecules should be subject to incessant 

 change; occasional mutual interchanges amongst the same appear 

 to me to be sufficient, for even if the number of interchanges be 

 small in comparison to the number of impacts, still, considered 

 alone, this number may be very great, and consequently it may 

 cause, in a short time, a considerable change in the original 

 mode of combination. 



As I arrived at the conclusions concerning the interchanges 

 which take place amongst the partial molecules of a liquid in a 

 manner totally different from, and independent of that of Wil- 

 liamson, I thought it advisable, even after becoming acquainted 

 with his memoir, to communicate my own views of the subject 

 unchanged, since, by so doing, I shall best render manifest how 

 far these two methods of viewing the subject serve mutually to 

 corroborate each other. 



