THE HEAT OF ABSORPTION OF VAPORS ON CHARCOAL.¹

Properties of the colloidal soil material /

“…The older hypothesis, which is supported by recent work of Lamb and Coolidge (31) and of Harkins and Ewing (23) on activated charcoals, holds that the adsorbed liquid is compressed at the surface of the adsorbent with a force equivalent to 20,000 to 37,000 atmospheres in the case of certain charcoals. The compressive force is considered as being due to an attraction between the molecules of the adsorbent and the molecules of the liquid, whereas the heat evolved is largely the heat of compression of the adsorbed liquid.…”

Changes in Volume that Occur when Dry Soils are Wetted with Water and with Chemical Solutions1

“…Of the two, the physical compression is probably the more important and is probably, responsible for most, if not for the entire, volume contraction. It is conceived that the water adsorbed by the soil particles is compressed (2,3,4) and its volume is thereby diminished.…”

Adsorption Compression on Cellulose and Wood. I. Density Measurements in Benzene

“…They concluded that the differences in the density values could not be due to differences in penetration. Lamb and Coolidge (13) calculated compressive force values as high as 37,000 atmospheres from their heats of adsorption measurements on charcoal, by assuming that all of the heat evolved is due to compression of the liquid. Cude and Hulett (5) made measurements of the density of charcoal in various liquids which they injected into the charcoal under pressure to facilitate penetration, and Howard and Hulett (10) made measurements in helium gas which they showed to be nonadsorbed on the charcoal.…”