In a previous paper, Broom and the author have shown that the process by which equilibrium is reached between the oxides of carbon, methane, and hydrogen, on the one hand, and amorphous carbon on the other, at temperatures above 700°C. is essentially chemical in character. In the case of methane, some experiments were carried out at lower temperatures, and these appeared to indicate that, while the gas was still absorbed rapidly, it could be recovered reversibly, suggesting that the mechanism of absorption was distinct from that by which the chemical equilibrium was finally established. This observation led to the following experiments on argon, which is not supposed to be taken up by carbon at moderately high temperatures. As in the former experiments, the principle of allowing the gas to remain for several days in contact with the carbon was adhered to; for though the rate of absorption was at first rapid at all temperatures, the time taken for equilibrium to be established increased as the temperature fell, and ultimately became so long that it was impossible to obtain results of any value in a reasonable time. A good deal of the published work on adsorption of gases seems to be vitiated by the fact that the experiments have been too hurried.
Argon and amorphous carbon, 15° to 710° C
