Influence of Voltaic Currents on the Diffusion of Liquids. 79 



The results obtained with the single meniscus apparatus, and with 

 the capillary tubes, support the conclusion that there is a small 

 amount of real transfer of the bulk of the liquid otherwise than by 

 diffusion. The rapidity of such movement appeared to vary, being 

 slowest in wide tubes with feeble electric current, quicker in the 

 single meniscus tube and in the capillary tube experiments, but in 

 no case was it as rapid as the movement of the mercury in a capillary 

 electroscope. The conditions of motion observed in these cases differ, 

 however, considerably from those in the experiments of Armstrong, 

 Quincke, Jiirgensen, and Wiedemann. In their experiments badly 

 conducting liquids only were used, and no movement occurred if good 

 conducting solutions were employed ; in mine it only took place in the 

 latter liquids. 



7. Melation to JElectric Osmose. 



In order to be enabled to judge more correctly respecting the 

 influence of " electric osmose," I made a number of experiments 

 similar to that performed by Porrett ("Annals of Phil.," vol. viii. 

 p. 74) . The results of these experiments have been made the subject 

 of a separate paper (see "Experiments on Electric Osmose," loc. cit.}, 

 for more convenient reference by future investigators. 



As in all those experiments (numbering 68) except one, the liquid 

 was observed to flow in the same direction as the positive electricity, 

 and showed no signs of reversal of movement with solutions of potassic 

 cyanide, yellow potassic chromate, acid chromate of potassium, or 

 sodic carbonate, I again conclude that the apparent movement of the 

 lower liquids in my experiments with a double meniscus apparatus is 

 of a considerably different character from that known as " electric 

 osmose." 



I also made experiments of electric osmose with the same pairs of 

 liquids as those used in the single meniscus apparatus in Experiments 

 Nos. 40 to 44. The electric currents were sent from strong to weak 

 solution in the osmose experiments corresponding to Nos. 40, 41, 42, 

 and 44, and from weak to strong in that agreeing with No. 43. In 

 each case the greatest osmotic transfer occurred in the direction of 

 the current, and was strong in No. 42 and weak in No. 44. These 

 directions of movement do not agree with those obtained in the 

 experiments referred to, and the results indicate that the direction 

 of the diffusion at a liquid meniscus is largely affected by the presence 

 of a diaphragm. 



8. Influence of Form and Dimensions of the Meniscus Tube. 



Experiments Nos. 40 to 44 were repeated with a meniscus tube of 

 the form of an hour-glass (fig. 7), and having an internal narrowest 

 diameter of about 3 millims., but no new results were obtained. 



