3185.     SIEVERTS, A., AND HAGEN, H.  [Ability of Cobalt to Absorb Hydrogen and Nitrogen.]  Jour. Phys. Chem. (U.S.S.R.), vol. 169, A, 1934, pp. 237-240; Brennstoff-Chem., vol. 15, 1934, p. 414; Chem. Abs., vol. 28, 1934, p. 6606.

                    Pure Co powder was first reduced with H2 at 800° and then at the same temperature in a quartz absorption flask stirring for 10 days.  Fresh H₂ was used continuously to measure the absorption at various temperatures.  The volume of the free gas was determined with argon.  The solubility of the H₂ increased with rising temperature, at atmospheric pressure and 600°, 0.08 mg. H₂ and 1,200° 0.5 mg. H₂ per 100 gm. Co were absorbed.  At varied pressures, the amount absorbed was proportional to the sq. root of the pressure.  The absorbability of technical Co turnings containing 2.5% Fe was the same as with pure Co.  N₂ is virtually insoluble in Co up to 1,200°.  A comparison of H₂ absorption for Fe, Co, and Ni showed that absorbability of Co up to 900° is only a little less than that of a Fe; above 900°, the difference becomes greater because here the γ Fe with its higher solubility appears.  The absorbability of Ni for H₂ is considerably greater than that of Fe.  The magnetic transformations with any of the 3 metals have no noteworthy effect on the H₂ absorption.  The differences in the properties of Fe, Co, and Ni, with regard to the absorbability, are correlated with the various crystal structures.

        SILINA, N. P.  See abs. 729.