274 THE ROYAL SOCIETY OF CANADA 



what skeptical of the work on this system as a result. Our work 

 would suggest that the phases present in the two systems at equili- 

 brium may not be identical. One measurement with an iron powder 

 containing some oxygen and a little carbon showed oxidation with a 

 gas of ratio of 2.0. Further experiments of this type will, we hope, 

 shed light on the discrepancy which now exists. 



We have been unable to obtain evidence that pure iron takes 

 up ferrous oxide in solid solution at 700, 750 or 960°C. We find that 

 the solid solutions of magnetite in ferrous oxide extend to a com- 

 position containing 76% iron at 750°C. These latter results are in 

 agreement with those of F., N., and R. and also with those of Mat- 

 subara. On the other hand Matsubara interpreted his other results 

 as meaning that iron took up large quantities of ferrous oxide in 

 solution. A more probable explanation of these results can be given 

 and this explanation niay be extended to cover his results on the 

 FeO — FezC equilibrium and also the results of most of the workers in 

 the iron-carbon-oxygen field. It also sheds new light on the iron- 

 carbon system. 



These experiments were carried out under the direction of 

 Professor J. B. Ferguson. 



The Electrodeposition of Copper and of Nickel on Aluminium 



By T. E. Everest 

 Presented by Professor W. Lash Miller, F.R.S.C. 



It has often been attempted, without success, to deposit electro- 

 lytically an adherent coating of copper or other metal on aluminium. 

 The difficulty seems to have been caused by the insufficiency of the 

 methods hitherto employed for cleaning and preparing the aluminium 

 surface. We find that if the surface to be plated is first made anode 

 in a solution of sodium hydroxide, rinsed, and transferred without 

 delay either to a cyanide-copper bath, or to an acid-copper bath, the 

 film of copper electrolytically deposited is adherent, will resist bending 

 until the aluminium fails, and will stand hammering, or heating to 

 200°C., without loosening. An adherent coating of nickel may also 

 be easily deposited, if the aluminium surface is prepared as described. 



The following procedure has proved satisfactory. The aluminium 

 surface is first brushed with a steel scratch brush, then joined to the 



