MR. 8. W. J. SMITH ON THE NATURE OF ELECTROCAP1LLAKY PHENOMENA. 73 



" depolariser."* When any one of the above solutions has stood for several hours over 

 mercury, the electro-capillary curve determined from it can be treated as independent 

 of the time, since it remains constant for a much longer period than a complete set of 



observations occupies. The E.M.F. of the Hg 



KC1 KI 



Hg cell was determined 



i 



by fixing the pair of H cells at a suitable distance apart, and adjusting so that the 



solutions in the cells were at the same level. The tubes were then joined across by a 

 capillary siphon (about 1 sq. millim. in cross-section) of which the total length was 

 about 60 centims. Contact within the cell was made by carefully drawing the 

 solutions to the centre of the siphon. Care was further taken to avoid any consider- 

 able shaking of the mercury surfaces. The diagram following represents the cell. 



The numbers given show that, for dilute solutions at any rate, the doable-layer 

 theory gives results in complete accord with the Nernst-Planck view of the potent i.-il 

 difference between KC1 and KT. If it be considered that the former is d priori tin- 

 more probable of the two hypotheses, the results may be taken to corroborate the 



YOU CXCIII. A. 



* ty. NKRNHT, 'Zeita. f. Physik. Chemie,' 4, 1889. 



L 



