igoy.] KOLLOCK AND SMITH— RESULTS IN ELECTROLYSIS. 343 



The milliammeter in the last two experiments showed a current 

 of one milHampere at the beginning, which at the end had fallen to 

 0.0005 ampere. 



There appears therefore to be no decomposition of potassium 

 ferrocyanide by currents lower than 0.23 volt. 



Experiments were then conducted in order to ascertain the effects 

 of low currents upon potassium ferricyanide. The salt used was 

 recrystallized several times. The solution contained 0.1323 gram of 

 the salt. This was equivalent to 0.0471 gram of potassium and 

 0.0852 gram of Fe(CN)6. There was no evidence of potassium 

 hydroxide in either cell after the current, having an electromotive 

 force of 0.3 volt and 0.5 milliampere, had acted for half an hour. 

 With 0.66 volt, giving a current of 0.002 ampere at the beginning 

 of the experiment acting for an hour, the anode increased 0.0309 

 gram in weight and but 0.0039 gram of potassium was found. 

 These experiments confirmed the observations made upon potassium 

 ferricyanide at the beginning of the work. The increase in weight 

 of the anode was out of proportion to the amount of potassium 

 present. Several other experiments with low currents gave similar 

 results. For example, a current of 0.4 volt, after one half hour's 

 action of the current showed only a small amount of potassium but 

 0.0279 gram of Fe(CN)6. When a current of o.i volt was passed, 

 the anode, after an hour's action of the current, increased 0.0223 

 gram, but there was no evidence of potassium hydroxide in the 

 solution. 



An explanation of these results was sought. As the solution 

 changed col^r, and showed the presence of ferrocyanide on testing 

 with ferric chloride, after electrolysis, it was thought that ferri- 

 cyanide might first be reduced to ferrocyanide. Four molecules of 



