Fressure- Mill /.metres of Hfercarj 
HYDROGEN AND OXYGEN IN CONTACT WITH HOT SURFACES. 
65 
The remarkable difference between the results of these two experiments is shown 
by the two curves for the partial pressures of the hydrogen reproduced in Diagram VI. 
By substituting inert nitrogen for the oxygen of electrolytic gas the rate of dis¬ 
appearance of hydrogen was increased something like seven-fold, a fact which at 
Diagram YI. Experiments with copper oxide. Partial pressures of hydrogen. 
Curve A, for 2H 2 + 0 2 ; Curve B, for 2H 2 + N 2 . 
once disproves the theory that the catalytic process involves a rapidly alternating 
series of reductions and re-oxidations of the surface. 
In a final experiment (VIII.) the quantity of “ oxidised ” gauze employed was 
only 27'8 grammes, instead of the 100 grammes used in previous experiments, in 
order to extend the combination over a longer period of time. The ratio H 2 /0 2 
found for samples of the gas shut oft in the “ bye-pass ” tubes during the experiment 
indicated hardly any perceptible permanent change in the catalysing surface during 
the fust hours, although towards the end of the experiment, when the pressure 
in the apparatus had fallen considerably, some slight permanent reduction apparently 
did take place. The rate of circulation was 1 in 40 minutes. 
Experiment VIII. 
November 4, 1904. 
Normal electrolytic gas over “oxidised” gauze. T = 214°. 
t. 
P. 
h. 
Ratio, H 2 /0 2 . 
t. 
P. 
k\. 
Ratio, H 2 /0 2 . 
hours. 
0 
millims. 
319-9 
hours. 
12 
millims. 
240-0 
0-0104 
1 
312-1 
0-0107 
24 
170-0 
0-0114 
1-96 
3 
299-0 
0-0100 
2-0 
48 
76-1 
0-0130 
6 
277-4 
0-0103 
— 
70 
29-2 
0-0148 
1-72 
9 
258-2 
0-0103 
1— ‘ 
ZD 
VOL. CCVI.—A. 
