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Adsorption isotherms have been obtained at 25°on silica gel, using water, n-propyl alcohol, acetic acid, salicylaldehyde and n-heptane as adsorbates. At each point on the. isotherms, the magnetic susceptibility of the adsorption complex was measured, using the Faraday method. At high pressures, near saturation, the observed diamagnetic susceptibilities of the adsorbed material corresponded to the susceptibilities of the bulk liquids, except in the case of salicylaldehyde where less than two layers were adsorbed. When less than a monolayer had been adsorbed, the susceptibilities differed from bulk liquid values except in the case of n-heptane. An increase was observed for water and n-propyl alcohol, and a decrease for acetic acid.

Adsorption-desorption isotherms were obtained at 28.8°for the system bromine-graphite. Magnetic susceptibilities for this system were measured at each point on the isotherms. At 28.8°about 500 mg. of bromine was adsorbed per gram at saturation. At the same time the diamagnetism of the graphite-bromine system had fallen to about 6% of its original value. Obviously the sorption of bromine had markedly altered the structure of the graphite. Furthermore at zero pressure of bromine the graphite retained almost one hundred mg. of the vapor per gram. Since the diamagnetism did not return to its original value at this point it seems very probable that the bromine molecules were retained in the swollen graphite structure.

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