50 
DR. W. A. BONE AND MR. R. V. WHEELER ON THE COMBINATION OF 
Experiment XV. 
January 12, 1905. 
Normal electrolytic gas over “ hydrogenised” gold. T = 250'. 
Rate of circulation = 1 in 45 minutes. 
t . . . . 
o i 
.3 
¥ 
1 
n 
2 hours 
p .. . . 
364-7 189-7 
138-3 
108-1 
62-6 
36 • 4 millims. 
h . . . 
— 0-5676 
0-5612 
0-5281 
0-5101 
0-5004 
ihe influence of hydrogen on the catalysing power of the surface is illustrated in 
the three pressure curves shown in Diagram V., below. Curve A is for the gauze in 
Diagram V. Experiments with gold gauze. Pressure curves for normal electrolytic gas. 
Curve A, surface in “ normal condition. Curve B, surface “ hydrogenised ” at 250°. 
Curve C, surface “hydrogenised” at 600°. 
its normal condition, B shows the transient stimulus imparted by previous exposure 
to hydrogen at 250°, whilst C shows the more permanent effect of “ hydrogenation” 
at 600°. 
Part V.—Experiments with Platinum. 
Bodenstein ( loc. cit.), from his experiments on the combination of hydrogen and 
oxygen over a dry platinum surface at ordinary temperatures, concluded that whereas 
an excess of hydrogen has no marked influence on the velocity of the reaction, excess 
of oxygen produces a considerable acceleration. We cannot entirely endorse this 
conclusion, at least so far as higher temperatures are concerned, since the following 
