1889.] Viscosity and Conductivity of Electrolytes. 



29 



in the cathode vessels is not the same for different degrees of 

 dilution when there is a porous diaphragm, but if you subtract 

 the amount due to the increase of volume of solution, the amounts 

 are approximately the same; hence if the increase of volume be 

 regarded as an entirely independent phenomenon the cations may 

 be assumed to be the same ; viz. atoms of copper, for all the dif- 

 ferent degrees of dilution. But the same result would be arrived 

 at if we assumed that in the more dilute solutions a greater 

 number of molecules were associated with the atoms. Assuming 

 that of the salt which is decomposed half is taken from the 

 anode vessel and half from the cathode vessel, I have calculated 

 the molecules that must be decomposed to give the required total 

 gain at the cathode which is tabulated for CuS0 4 by Wiedemann 

 for solutions of different strengths. They are as follows 



Table III. 



The molecules which are actually decomposed may be more 

 complex than those given, by combination with molecules of solu- 

 tion, but the association of such molecules with the ions would not 

 affect the ultimate relative distribution of the electrolyte. More- 

 over all the ions in a specific solution need not be of the same 

 order of complexity. 



It would be a natural consequence of this view to suppose 

 that when the solutions became very dilute, the number of mole- 

 cules of water associated with the moving atoms would be very 

 large, ultimately being proportional to dilution ; in that case the 

 electrolysis would depend mainly on the motion of these large 

 molecular aggregates past each other and the resistance would be 

 of the nature of ordinary viscosity. Under these circumstances 

 the number of molecules associated might depend on the number 

 and be independent of the nature of the atoms and the ionic 

 velocities, and the resistance of all electrolytes would tend to the 

 same value as they are known to do in solutions of extreme 

 dilution*. 



* F. Kolrausch, Gegemoartige Anschauung, <£-c., p. 28. 



