1920-21.] The Adsorption of Gas under Pressure. 
119 
XIII. — The Adsorption of Gas under Pressure. By Henry Briggs, 
D.Sc., Ph.D., A.R.S.M., and William Cooper, M.A., B.Sc. 
(MS. received June 15, 1921. Read July 4, 1921.) 
I. Introduction. 
In 1917 Messrs F. C. Short, B.Sc., and F. W. Moore, of Walsall, applied for 
a patent for a method of storing gas, under compression, in cylinders or 
containers filled with charcoal which had been impregnated with a metal 
(e.g. iron, nickel, palladium) in a very fine state of division. The immediate 
intention of the inventors was to provide a compact method of storage of 
coal-gas serving as fuel for internal combustion engines. They realised 
that by filling a cylinder with impregnated charcoal its gas-capacity would 
be augmented. Independently, in 1919, one of us began experiments to 
ascertain if it were feasible to increase the capacity of a nitrogen cylinder, 
without increasing the pressure, by loading the cylinder with an un- 
impregnated activated charcoal before compressing the gas into it, and 
the results given below indicate that such an increase is in some degree 
possible. It is unfortunate that experiments with the gas in which we 
were principally interested, namely, oxygen, had to be limited to colloidal 
silica, this being the only non-inflammable adsorbent available ; for had 
oxygen been compressed into charcoal there would have been grave risk of 
explosion. We have recently learnt that similar experiments have been 
carried out on coal by Mr J. I. Graham at the Doncaster Coalowners’ 
Research Laboratory, though at the time of writing his results have not 
been published. The only published investigation known to us on the 
effect upon gaseous adsorption of pressures higher than atmospheric 
is that of Sir James Dewar,* who ascertained the volume of hydrogen 
taken in by a mass of 6’7 grams of cocoanut charcoal at — 185° C. He 
found that the charcoal adsorbed a volume which increased from 620 c.c. 
at atmospheric pressure to 1050 c.c. at 10 atmospheres, and that between 
10 and 25 atmospheres no further gas was taken up. 
The use of a porous medium, such as kieselguhr or asbestos wool, in 
acetylene cylinders is well known. Its function is to absorb the acetone 
which, in those cylinders, is used to dissolve the gas. The solution of 
acetylene in acetone is, however, a phenomenon of an entirely different 
kind to the adsorption of, say, nitrogen by charcoal. 
* “ Studies on Charcoal and Liquid Air,” Proc. Roy. Inst ., xviii (1906), p. 433. 
