4 THE ROYAL SOCIETY OF CANADA 



hours' reduction there is still unchanged NiO which slowly undergoes 

 reduction to form more and more complex. 



EXPERIMENTAL 



In the experiments here described the following apparatus was 

 employed except for the alterations noted in some cases. 



rnu 



x^ 



AA are gas burettes. BB are guard tubes containing sulphuric acid on pumice. 

 CC, also containing sulphuric acid on pumice, were the tubes weighed in water 

 determinations. D is the tube holding the catalyst. E is a small manometer. 



Experiment 1. 



A quantity of nickel nitrate was ignited. Two grams of the 

 resulting oxide was dissolved in nitric acid and the solution evaporated 

 to dryness on the water bath. This nitrate was dissolved in a little 

 water, and asbestos, which had been purified by extraction with 

 acids, washing and ignition, was added. This asbestos holding nickel 

 nitrate was placed in a quartz tube in a combustion furnace and 

 heated to a high temperature. The quartz tube containing the nickel 

 oxide on asbestos was placed in the apparatus train in place of the 

 U tube d and heated in an air bath at 275°C. Electrolytic hydrogen, 

 purified by passage over heated copper gauze and then through 

 sulphuric acid dryers, was then passed through the apparatus. The 

 following results were obtained : 



Reduction of Nickel Oxide at 275°C. 

 Time Weight of water in grams 



è hour 0.0742 



I- " 0,0280 



1 " 0.0446 



