1. Dunn, J. S., J. Inst. Met., 46, 25 (1931). Preston and Bircumshaw, Phil. Mag., 20, 706 (1935). Krupkowski and Jaszczurowski, Rev., Met., 33, 652 (1936) and others.
2. Iitaka, I., and Miyake, S., NATURE, 136, 437 (1935) and 137, 457 (1936).
3. See, for example, Adam, N. K., "The Physics and Chemistry of Surfaces" (chapter iv).
4. Desch, C. H., "The Chemistry of Solids", p. 53.
5. Dobinski, S., Phil. Mag., 23, 397 (1937).