68 Kansas Academy of Science, 



The experiments reported herewith were carried out with appa- 

 ratus quite similar to that described above. Copper was first ti-ied, 

 to show whether or not the right conditions had been secured. A 

 solution of copper sulfate several times recrystallized was made, and 

 standardized gravimetrically by a number of closely agreeing deter- 

 minations made by precipitation with sodium carbonate, igniting 

 and weighing the copper as copper oxid. The results and details 

 are shown in table I. The solution to be electrolyzed was aciditied 

 with twelve drops of sulfuric acid 1:4, and occupied a volume of 

 65 cc. 



Table I. Copper. 



•A new standard solution made up. 



The salt used for the estimating of iron was ferrous ammonium 

 sulfate in ammonium oxalate sulution, 1:6, 50 co After running 

 for ten minutes the motor was stopped and the sides of the beaker 

 were washed down, as was done with all the experiments with the 

 rotating cathode. It was found that great care was needed in dry- 

 ing the deposit on the crucible by dipping in water, then in alcohol, 

 and holding over a low flame of a Bunsen burner. The deposit was 

 removed by dipping in concentrated hydrochloric acid for a few 

 seconds, and came ofif in flakes. The completeness of the deposi- 

 tion may be tested at any time toward the end, by removing a drop 

 of the S'jlution, acidifying with hydrochloric acid, and adding po- 

 tassium sulfocyanide. The results are given in table II. • 



