DE. W. A. BONE AND MR. R. V. WHEELER ON THE COMBINATION OF 
36 
Experiment Y. 
August 3, 1904. 
Original mixture = 3H 2 + 0 2 (nearly). T = 400° 
circulation = 1 in 60 minutes. 
Rate of 
t. 
P H, 
p o. 
k o 2 . 
t. 
P. 
L 
hours. 
millims. 
millims. 
hours. 
millims. 
0 
286-0 
98-7 
— 
_ 
0 
358-4 
_ 
1 
202-1 
56-7 
0-1508 
0-2407 
1 
218-8 
0-2143 
H 
170-5 
41-0 
0-1498 
0-2544 
2 
133-1 
0-2151 
2 
145-2 
28-3 
0-1472 
0-2712 
3 
78-4 
0-2200 
3 
118-8 
15-1 
0-1272 
0-2718 
4 
47-6 
0-2192 
H 
110-9 
11-2 
0-1176 
0-2700 
5 
25-0 
0-2313 
Experiment YI. 
August 4, 1904. 
Normal electrolytic gas over “ hy- 
drogenised ” surface. T = 400°. 
Rate of circulation = 1 in 60 
minutes. 
The immediate effect of the excess of hydrogen in Experiment V. was a marked 
stimulation of the surface, which increased up to nearly the end of the second hour, 
when, it would appear, the surface had become fully hydrogenised. In conformity 
with this idea, the rate of steam formation was, during the interval 0 to 2 hours, 
nearly proportional to the partial pressure of the hydrogen; afterwards, however, it 
was largely governed by the oxygen pressure. 
The stimulation of the surface by hydrogen is not only well marked, but is also 
shown to he very enduring, in Experiment VI. 
Second Series with Silver Gauze at 400°. 
At the outset of this series of experiments, the gauze was taken out of the 
combustion tube and heated to a temperature just short of the melting-point. A 
marked change took place both in its outward appearance and mechanical properties. 
The metal had lost its original elasticity and become exceedingly brittle ; its surface 
had assumed a beautiful frosted appearance, and was covered with minute pits and 
excrescences, as will be seen from the photomicrograph B of it reproduced on p. 37. 
This should be compared with A, which shows the original condition of the surface. 
The whole behaviour of the metal suggested the breaking up of a hydride, and 
recalled the experiments of Beilby and Henderson on the action of ammonia on 
metals at high temperatures. # In the case of silver, they found that “at 800° the 
polished surface of fine silver wire acquired a frosted appearance, and when examined 
with the microscope the wire was found to be coated all over with minute rounded 
blisters or bubbles, whilst there was very distinct evidence of ‘ spitting.’ The 
elasticity of the metal was also very greatly reduced.” They attributed the change 
* ‘Trans. Chem. Soc.,’ 1901, vol. 79, p. 1245. 
