6 Taylor, Method of Separating Cobalt and Nickel. 



when the electrolysis was carried on through the night 

 (altogether about 17 hours) 50 c.c. gave O" 15 37 gramme 

 of cobalt. Possibly the larger amount represents the 

 true strength of the solution. 



Mixtures were next made of 50 c.c. of each of the 

 two solutions, the separation effected as before, and both 

 the cobalt and nickel determined electrolytically. In one 

 experiment, where the electrolysis of the cobalt solution was 

 allowed to proceed throughout the night, 0"i542 gramme 

 of cobalt and 01 352 gramme of nickel were obtained. In 

 another, where the cobalt solution was electrolysed for 

 seven hours, the numbers were 0"i532 and 0-1347 

 respectively. 



In addition to the above results obtained by myself, 

 some experiments on this method of separation have 

 been made by Mr. David Segaller, A.R.C.S., Dublin, with 

 equally satisfactory results. 



The above results are very much better than those 

 quoted by Rose and Henry for the original method. 

 This may be due to the fact that my materials were 

 probably purer than any they were able to obtain. The 

 results demonstrate quite satisfactorily that by this method 

 the separation of cobalt and nickel is not only rapid, but 

 complete. 



The process not only acts well quantitatively, but I 

 recommend it very strongly for the separation and 

 detection of cobalt and nickel in the ordinary process of 

 qualitative analysis. The mixed sulphides of cobalt and 

 nickel are dissolved in the usual way in dilute hydro- 

 chloric acid with the aid of a crystal of potassium chlorate. 

 The liquid is then boiled down just to dryness in order 

 to expel the free acid. The residue is taken up with 

 water, and precipitated barium or calcium carbonate and 



