3623.     ---------------.  [ALBRECHT., W. H., AND WEDEKIND, E.]  [Distinguishing the Different Types of Ferric Oxides and Hydrated Oxides by Their Different Magnetic Properties.  IV.]   Ztschr. anorg. Chem., vol. 202, 1931, pp. 209-226; Chem. Abs., vol. 26, 1932, pp. 2630-2631.

        Data previously reported are correlated and explained.  Both natural and pure synthetic oxide hydrates exhibit low magnetic susceptibilities.  Although these are normal, they do not always show well-defined X-ray interference patterns.  Some preparations with poor X-ray interference patterns are normal, whereas others with characteristic patterns exhibit magnetic abnormality.