96 THE ROYAL SOCIETY OF CANADA 



From the experiments of the author it does not seem that the 

 method of Neumann can be used for quantitative work. Sodium 

 acetate, ammonium acetate or potassium cyanide when used in a 

 corresponding way do not yield useful results. 



III. ELECTROLYSIS OF NICKEL AND COBALT CHLORIDES. 



The electrolytic deposition of nickel from ammoniacal chloride 

 solutions is generally regarded as less satisfactory than that from the 

 ammoniacal sulphate. Oettel has shewn the conditions under which 

 satisfactory results could be obtained. The writer has found that 

 equally satisfactory results are obtained for cobalt chloride by the 

 addition of a small amount of sulphuric acid to the electrolyte. 



Experiment I. To a solution of cobalt chloride was added three 

 cubic centimetres of strong sulphuric acid, 30c. c. of strong ammonia 

 and water sufficient to increase the volume to 150c. c. By using 

 a revolving gauze cathode at 4 amperes and 5 volts the deposition 

 was complete in 20 minutes. The deposit was dark but quite 

 adherent. 



Experiment II. To an equal amount of cobalt chloride was added 

 three cubic centimetres of strong sulphuric acid. The solution 

 was evaporated till fumes of sulphuric acid were freely evolved, 

 when the solution was rendered ammoniacal as before and diluted 

 to 150c. c. From this solution of ammoniacal sulphate of cobalt 

 the metal was deposited under conditions employed in the 

 previous experiment. The separation was complete in half an 

 hour. The results of these experiments are as follows: 



Experiment I. Cobalt deposited •1294gms. 



Experiment II. Cobalt deposited -1293 gms. 



From these and other experiments it therefore appears that cobalt 

 chloride may be employed for electrolytic determination provided the 

 same amount of sulphates be present as is required for the satisfactory 

 plating from sulphate of cobalt. 



III. THE DIMETHYLGLYOXIME METHOD. 



In 1905 Tschugaefï^ pointed out the value of dimethylglyoxime as 

 precipitant of nickel and suggested its usefulness in the separation 

 of nickel from cobalt. Later a series of experiments conducted by 

 Brunck^ made it plain that this separation was quantitative and 



1 Berichte XXXVIII, p, 2520. 



2 Zeitschrift fur Angew Chemie XIX, p. 1793 and XX, p. 834 and p. 1844. 



