Influence, of Voltaic Currents on the Diffusion of Liquids. 11 



duced appeared to be due to the heat of conduction resistance and 

 the explosive action of the bubbles of steam. 



In another experiment I employed two liquids and a current from 

 twelve Grove's cells in single series, the lower liquid being a mixture 

 of 3 volumes of saturated solution of cupric sulphate and 2 volumes of 

 a mixture of 1 volume of sulphuric acid and 2^ volumes of water ; 

 and the upper one of 1 volume of sulphuric acid and 7 volumes of 

 water. The action at the two meniscuses produced no visible flow of 

 liquid through the hole in the talc. 



From these results, from considerations already stated (see p. 68, 

 ■et seq.), and also from the circumstance that in Armstrong's experi- 

 ment pure water (a liquid of great electric conduction resistance) was 

 necessary, and in the experiments of other investigators the flow of 

 liquids required badly conducting liquids, and either porous diaphragms 

 or tubes of capillary diameter, I conclude that the bodily flow of the 

 unchanged mass of the heavier liquid in my experiments is, to a large 

 extent, only apparent. The considerable length of time also required 

 for the apparent flow is consistent with this conclusion. 



6. Experiments with Capillary Tubes. 



In order to test the question whether a similar to-and-fro movement 

 by an electric current takes place with miscible liquids in capillary 

 tubes, as occurs with mercury and an aqueous solution in a capillary 

 electroscope, and also to ascertain whether ]the quicker movements of 

 the liquids in Experiments Nos. 40, 41, 4-2, and 43 was of this kind, I 

 made a number of experiments with a small apparatus similar to 

 fig. 4 (see p. 70), having (in place of the inner cylinder and tube) a 

 capillary tube, fig. 6 (containing the lighter liquid) immersed in the 



Fig. 6 



lieavier solution, the lighter liquid being very strongly coloured with 

 xl mauve " aniline dye. The electric currents employed were from a 



