551. CHEVALIER, R., AND MATHIEU, S. [Variation in Magnetic Susceptibility of Hematite Powder With Size of Grains.] Compt. rend., vol. 204, 1937, pp. 854-856; Chem. Abs., vol. 31, 1937, p. 3352.

551. CHEVALIER, R., AND MATHIEU, S. [Variation in Magnetic Susceptibility of Hematite Powder With Size of Grains.] Compt. Rend., vol. 204, 1937, pp. 854-856; Chem. Abs., vol. 31, 1937, p. 3352.

Three samples of hematite were separated, by powdering, sifting, and levigation in EtOH, into 9 samples of different average diameters, 500-10μ, and the magnetic susceptibility _X of each was determined in a field of 700 gausses. _X diminishes by about 10% as d decreases from 500 to 100μ, then more rapidly to only about 25% of the initial value for d=10μ. Extrapolated to d=0, _X=20-30X10^-6, or approximately that of powdered artificial rhombohedral Fe₂O₃.