246 J. Olsen — Investigation into the Existence of 



direction of the deflections were the same as 

 before. In the experiments of the effect of an 

 electrostatic charge on a solution which has 

 been subjected, first, to an electromotive force 

 less than the electrolytic limit of decomposi- 

 tion, and then on the solution after the decom- 

 position limit has been exceeded, a cell of the 

 form shown in fig. 3 was used. 



a and a' are the electrodes connected to the galvanometer 

 circuit ; A and A' are the electrodes which may be connected 

 to the Daniell, and T is the disk which may be charged elec- 

 trostatically. 



As has been stated, a larger and more prompt effect was 

 noticed when an electromotive force, although below the 

 decomposition value, w^as connected up to a cell and then an 

 electrostatic charge brought up than when no current had 

 previously been allowed to act upon it. Also that a pair of 

 electrodes became of the same sign as the nearest electrode 

 connected to a Daniell, this also although below the decompo- 

 sition value of the solution. 



This may be explained as follows : 



Either the ions already free are heaped up around the elec- 

 trodes as they become charged by the current, or the current, 

 although below the decomposition value for the evolution of 

 gases, yet decomposes the electrolyte. Accordingly the fol- 

 lowing experiment was performed. 



According to H. 0. Jones,* strong acids and bases are com- 

 pletely dissociated at dilutions of about one one-thousandth nor- 

 mal solutions. If there is complete dissociation, then there 

 are of course no more molecules to be decomposed by the 

 current unless the water decomposes. I took, in order to be 

 sure of complete dissociation, a one-fourteen-hundredth nor- 

 mal solution of sulphuric acid, and using the cell shown in 

 figure 2, subjected the outer electrodes A and A^ to a potential 

 difference of about 0*8 volt. 



After taking several deflections by closing the aa' or galva- 

 nometer circuit, in order to get the cell into a somewhat steady 

 condition, and noting the direction of the deflections, the AA' 

 circuit was connected up to a potential difference of about 0'8 

 volt from a Daniell, in such a direction as to increase the 

 deflections in the galvanometer circuit. It did increase the 

 deflections and on reversing the direction of the current from 

 the Daniell, the deflections in the galvanometer circuit 

 decreased and finally reversed. 



Here no decomposition of the sulphuric acid could take 

 place as it was completely dissociated before, and the voltage 



* Theory of Electrolytic Dissociation, p. 190. 



