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THE ROYAL SOCIETY OF CANADA 



of that group may be separated by sulphuretted hydrogen, after 

 which the filtrate is concentrated to lOOc.c by boiling. Finally add 

 three cubic centimetres of strong sulphuric acid and 30c.c of strong 

 ammonia and deposit the nickel and cobalt by electrolysis, using a 

 revolving cathode with a current of 5 amperes and 5 volts. The pre- 

 cipitation is complete in half an hour. 



Details. 

 I. 



Separation of Iron and Nickel Chlorides by Pb304. 



II. 



Separation of Iron and Cobalt Chlorides I and II by Pb304; III by PbO. 



From the above results it is apparent that: 



1. Nickel and Iron as chlorides can be satisfactorily separ- 

 ated by adding Pb304 to the nearly neutral solution and boiling. 



2. Under similar treatment there is a loss of about ten per 

 cent when this method of separation is applied to chlorides of 

 Cobalt and Iron. 



3. The separation of Cobalt and Iron by means of litharge is 

 scarcely more complete than that obtained by using red lead. 



The separation of nickel from iron by means of litharge was 

 first suggested by Field. ^ It appears from the above experiments 

 that litharge is as unsatisfactory as red lead for the cobalt iron separ- 

 ation. The chief advantage of red lead as against litharge consists 



^Chemical News Vol. I, page 5, 1859. 



