6 THE ROYAL SOCIETY OF CANADA 



Experiment 2. 



In order to decide this the nickel on asbestos was oxidized by 

 free oxygen at a red heat and then reduced at 275° by hydrogen for 

 five hours. The water obtained during the first half hour was 0.0779 g. 

 and in the last half hour 0.0060 g. One end of the quartz tube was 

 then closed and the other end connected with a vacuum pump and 

 the tube heated for one hour at the full heat of the combustion furnace 

 under a high vacuum. It was then cooled and held under suction 

 for a further forty-five minutes and the water adsorption tube weighed. 

 The water obtained amounted to only . 0018 g. Thus the adsorbed 

 hydrogen had been expelled almost completely without effecting any 

 further reduction. Hence the water obtained in the above experi- 

 ments after standing over night in relatively such large amounts is 

 not due to water vapour adsorbed on the nickel but to adsorbed 

 hydrogen which slowly removes more oxygen from that remaining in 

 the nickel. 



The reduction of nickel oxide at 275° was again performed, the 

 reduction being carried out for a longer time, with the following 

 results: 



Time Water in Grams 



1 hour 0.0704 



0.0430 



. 0428 



0.0110 



0.0166 



. 0086 



. 0074 



The tube was then rapidly cooled with cold water and hydrogen 

 again passed at 275°. . 



Time Water in Grams 



I hour 0.0158 



è " 0.0000 



The cooling and reheating was repeated when at 275° for \ hour. 

 . 0092 g. water was obtained. 



The apparatus was allowed to stand over night and hydrogen 

 passed at 275° on the following day. 



Time Water in Grams 



I hour . 0500 



The tube was cooled and then again heated at 275°. 



