IN GASES: HYDROGEN, CARBONIC OXIDE, AND OXYGEN. 
629 
Dry vacuum . 
[Wet vacuum 
On adding carbonic oxide 
On adding oxygen . 
] ine in 
eudiometer. 
Barometer. 
Temp. C. 
Difference. 
millims. 
mill'ms. 
5 
586-2 
14-13 
12-0 
5 
548-2] 
Table 12’0 
Aq. tens. = 0"0 
5 
663-7 
1416 
5 
905-3 
14-18 
Tbis mixture would not explode when sparks were passed through it. 
On adding carbonic oxide 
991A 
12-4 
This mixture would not explode when sparks were passed through it. 
A second sample was then brought into the eudiometer 
Line in 
eudiometer. 
Barometer. 
Temperature. 
Difference. 
Dry vacuum. 
5 
millims. 
537'0 
13°4 
millims. 
11-2 
On adding- carbonic oxide . 
5 
696-2 
13-45 
Table 11-4 
On adding oxygen .... 
5 
910-9 
13-0 
This mixture would not explode. It was then passed into the laboratory tube and 
allowed to stand for a few seconds over a drop of water. On returning it to the 
eudiometer, and again sending a spark through, the mixture exploded. 
Since it had been already shown that carbonic oxide is oxidized by steam at a high 
temperature, it seemed possible that carbonic oxide is incapable of direct union with 
oxygen, but is burnt indirectly by steam with liberation of hydrogen. The steam 
would act as a carrier of oxygen to the carbonic oxide by a process of alternate 
oxidation and reduction, somewhat analogous to that undergone by nitric oxide in the 
sulphuric acid chamber. I have made many experiments to test this hypothesis, both 
on account of the interest attaching to such a “ catalytic ” decomposition among the 
simplest gaseous bodies, and of its important bearing on the mode of division of the 
oxygen between the hydrogen and carbonic oxide in incomplete combustions of these 
gases. 
The carbonic oxide used in these experiments was prepared by gently heating re- 
crystallized sodic formate with concentrated sulphuric acid in a glass flask. The gas 
was passed (1) through a wash-bottle containing a strong solution of potash, (2) through 
a wash-bottle containing concentrated sulphuric acid, (3) through a U-tube containing 
fragments of solid caustic potash, and (4) through a (J-t.ube containing frag- 
