1920-21.] The Adsorption of Gas under Pressure. 
127 
Summary. 
1. Experiments made at 15° C. with various adsorbents and gases 
(chiefly nitrogen and hydrogen) show that a cylinder filled with adsorbent 
granules has a capacity for dry gas under a given pressure which is 
generally greater than its capacity when containing no adsorbent. 
For example, a cylinder charged with nitrogen at 35 atmospheres has 
its capacity increased by 66 per cent, by filling it with cocoanut charcoal. 
2. Sudden outbursts of firedamp in coal-mines are the result of re- 
leasing immense quantities of gas adsorbed under pressure in coal. 
3. The logarithmic relation derived by Williams is shown to apply 
to the adsorption isotherms of gases above their critical temperature up 
to pressures of 100 atmospheres, providing a correction be applied for 
the gas in the capillaries which is not adsorbed, but which exists under 
simple compression. 
(. Issued separately August 23, 1921.) 
