Pressure - Millimetres of Mercary 
HYDROGEN AND OXYGEN IN CONTACT WITH HOT SURFACES. 
31 
partial pressure of the hydrogen throughout, and the values “ ” showed that the 
surface was no more than normally active. The results of the four experiments are 
tabulated on the next page. 
Diagram III. Experiments with magnesia. Pressure curves for normal electrolytic gas. 
Curve A. Surface in “ normal ” condition. 
,, B. “ Hydrogenised ” surface. 
,, C. Surface “ dehydrogenised ” by exposure to oxygen. 
