Passage of Electricity through Liquids. 



285 



Salt. 



Hittorf. 



Weiske. 



P. 



n'. 



P. 



n. 



KCl . 



NaCl - 

 CaCl2 J 

 BaCl2 J 



3-837 

 5-485 

 97-87 

 3-472 

 20-71 

 104-76 

 3-95 

 20-92 

 138-26 

 8-39 

 79-6 

 126-5 



0502 

 0-500 

 0-508 

 0-648 

 0-634 

 0-628 

 0727 

 0-683 

 0-673 

 0-642 

 0-616 

 0-614 



8-24 



23-15 



52-73 



9-85 



3404 



117-7 

 1021 

 26-40 

 80-83 

 11-81 

 22-79 



185 6 



0-517 

 514 

 0-518 

 0-686 

 0-685 

 0-680 

 0-689 

 0-688 

 0-692 

 0-531 

 0-528 

 0-533 



Notwithstanding the very different circumstances under which 

 the various observers performed their experiments with different 

 apparatus, yet they give nearly the same vahie of n. Owing to 

 the disturbing influences already mentioned, we certainly cannot 

 expect greater concordance, and may put 



M 

 n _ n _ « _ C^ 



In most cases n differs from ^ ; and then the partial mole- 

 cules move with different velocities to the electrodes, as follows 

 immediately from equations (7) and (17). 



§ 68. 



With a few solutions of salts, and certainly the concentrated 

 solutions of P Cd, Cl^ Cd, Cl^ Zn, P Zn in water or diluted solu- 

 tions of the same salts in absolute alcohol, and P Cd in methy- 

 lated alcohol, Hittorf* observed an increase of the concentration 

 at the anode; and this led me to conjecture that here we had 

 the case given in expression (11^) (§ 54), that both e and e' 

 would have the negative sign. 



Hittorf assumes that the partial molecules are always propelled 

 in opposite directions by the electrical current, and endeavours 

 to reconcile this with the phenomenon discussed in the foregoing 

 sections, by assuming that the concentrated solutions of the salts 

 in question contain double salts, which consist of two or more 

 equivalents of the corresponding salt, for example 1^ Cd, and are 

 acted upon by the electrical current like double salts formed of 

 two different metals. As the electrical current resolves aqueous 

 * Pogg. Ann. vol. cvi. pp. 542-565 (1859). 



