MEASUREMENTS OF ELECTROLYTIC MIGRATION II 



Anovialous Results. 



Of remarkable results there are many. Highly interesting 

 are the researches of Daniell and Miller in 1844. These well 

 known and capable experimenters, fully alive to the significance 

 of the results they were obtaining, found that in many cases 

 components now recognized as cations did not move at all. 

 Later measurements agree in showing that in these very solutions 

 the cation moves about as fast as the anion. Hittorf and others 

 have suggested explanations for Daniell and Miller's results, 

 but unfortunately the explanations suggested only make things 

 worse. 



Chassy, in 1890, made a number of measurements with 

 mixtures of two and more electrolytes. His results are sum- 

 marized by Ponsot ' and are quite at variance with the pre- 

 dictions of the present theory ; his is the only experimental 

 work in this field. 



Bein, in 1898, found for ammonium hydroxide a transport 

 number widely different from that predicted by Kohlrausch's 

 law of the independent migration of the ions. In 1904 I obtained 

 a similar result for acetic and propionic acids. These are the 

 only measurements that have been made with very weak electro- 

 lytes, and all three obey Ostwald's law ; these results should 

 not be so difBcult to believe when Jahn and Nernst hold that the 

 mobility of an ion varies greatly with the concentration, without 

 any more evidence than that the conductivity and freezing 

 points which agree so well with one another both refuse to obey 

 Ostwald's law, although the latter does not take into account 

 the possible displacement of the equilibrium by the electrical 

 forces. 



The accurate measurements of Noyes and Sammet in 1902 

 gave a result for hydrochloric acid differing by four percent 

 from that calculated from the careful conductivity measurements 

 of Goodwin and Haskell ;^ the transference measurements have 

 been confirmed in Jahn's laboratory by Joachim, and the diver- 

 gence has to be regarded as real. Divergences equally great 

 even amongst the most carefully measured electrolytes are so 



' Comptes rendus, 13S, 192. 

 ^Phjs. Review, ig, 369 (1904). 



