627 



As the relation of llie [loteiiliaLs for {a) we obtain ^-^ or 14; as 

 the relation of tlie resistances : 19. 



From the conil)ination {h) we obtain for the potentials ^ or 26, 

 for the resistance 28. 



This a^ireenient undoiibtedlv tolls niiieh iji favonr of the above 

 raeiitioiied theory. With concentrations somewhat lai-ger than 60 the 

 agreement might be better still. 



5. The material of Riéty ') is only once snitable for testing the 

 relation (2). 



For so far l;is measnrements have been execnted with solutions 

 of salts other than chlorides his measuring electi-odes wei-e non- 

 reversable ones and his results are therefore useless for quantitative 

 veritication. I have only been able to tind one combination of 

 chloi'ides where concentrations have been measured which are com- 

 parable with limit values : they are KCl and HCl. For As.,S3-sol 

 these limit values have been determined to 50 and 31 niMol p. L. 

 respectively *). 



Now from his experiments Riéty has calculated the potential at 

 the capillary wall in certain units for 0.01 n. KCl as 3.1. We can 

 use this tigure again for comparison purposes at it is directly propor- 

 tional to the chai'ge. 



In the case of HCl he determined for 0.005 n : 3.39, for 0.010 ii -. 2.8, 

 For the comparison with 0.01 n HCl w^e must know the potential at 

 the concentration |-^ X O.OJ = 0.0062. This, 1 have intei-polated by 

 assuming that the logarithms of the poteidials are «lirectly propor- 

 tional to those of the concentrations, after I had first convinced 

 myself that this interpolation^) formula was quite satisfactory in the 

 longer series stated in Riety's paper. We then tind 3.2 which is 

 again a splendid agreement. 



6. Quantitative comparisons with the tiivalent cation are diflieult 

 to draw, because the •/-'^'^i-lnes thereof are either not known or uncer- 

 tain. From the treatises cited on p. 648 we, howexer, get the 

 impj-ession that the •/-'^'^lues diverge very little from zero, as is also 

 expected from Table IV of the preceding communication, because a 

 complete discharge takes place already at a concentration of 0.8 fi mol. 



7. A no less striking [)arallelisni l)etween charge and limit \alue 



1) Ann. de chim. et de phys. [8], 30, 1 (1913). 



-) FreUiCdlich, Kapillarchemie (Leipzig 1909) Table 81. True, those are -, - and 



not ::f;-va]ues, but with these univalent ions, this cannot have any serious influence, 



^) To this formula should only be attached the significance of an interpolation formula. 



41 

 Proceedings Royal Acad. Amsterdam. Vol. XVU 



