G68 
MR. H. B. DIXON ON CONDITIONS OF CHEMICAL CHANGE 
Table XXXVI.—Temperature of Eudiometer = 80° C. 
Reference 
No. 
Before the explosion. 
After the explosion. 
Oxygen. 
Carbonic 
oxide. 
Hydrogen. 
Carbonic 
oxide. 
Carbonic 
acid. 
Hydrogen. 
Steam. 
Pressure. 
a. 
115 
15-4 
517 
48-3 
42-0 
97 
27-4 
20-9 
millims. 
150 
3-3 
116 
42 T 
9-6 
267 
21-6 
200 
3-6 
117 
55 
427 
8-9 
26-6 
2L8 
300 
3-9 
118 
55 
42-5 
91 
264 
22 2 
400 
4-0 
106 
55 
55 
55 
42-9 
87 
26-6 
21-8 
1000 
4-0 
This mixture would not explode when the spark was passed under 100 millims. or 
125 millims. pressure. At 150 millims. it exploded. The critical 'pressure is found 
to he between 300 millims. and 400 millims. Below the critical pressure a different 
equilibrium is established. The constant coefficient for this mixture is the same as 
that for a mixture containing three volumes of hydrogen to one volume of carbonic 
oxide. 
From the experiments previously given the following table is made up. 
Table XXXVII.—Temperature of Eudiometer = 100° C. 
Reference 
No. 
Before the explosion. 
After the 
explosion. 
Co- 
Oxygen. 
Carbonic 
oxide. 
Hydrogen. 
Carbonic 
oxide. 
Carbonic 
acid. 
Hydrogen. 
Steam. 
Pressure. 
efficient. 
a. 
114 
17-6 
73-4 
26-6 
52-0 
21-4 
127 
13-9 
millims. 
100 
27 
110 
535 
19-9 
111 
155 
400 
3-7 
98 
55 
55 
55 
53-7 
19-6 
11-4 
152 
1000 
37 
This mixture exploded under 100 millims. pressure at 100°. The “critical pressure” 
is below 400 millims. 
Another set of experiments was made with a mixture containing about three times 
as much hydrogen as carbonic oxide. To 100 volumes of the combustible gases, 15'8 
volumes of oxygen were added. 
Table XXXVIII.—Temperature of Eudiometer = 100° C. 
Reference 
No. 
Before the explosion. 
After the 
explosion. 
Co¬ 
efficient. 
a. 
Oxygen. 
Carbonic 
oxide. 
Hydrogen. 
Carbonic 
oxide. 
Carbonic 
acid. 
Hydrogen. 
Steam. 
Pressure. 
119 
15-8 
24-5 
75-5 
20-4 
41 
48-6 
26-9 
millims. 
100 
2-8 
120 
55 
55 
21-2 
33 
47-2 
28-3 
oOO 
3-8 
104 
55 
55 
55 
21-2 
33 
47-0 
28-5 
1000 
4-0 
The critical pressure is above 300 millims. 
