1. D. M. Wrinch, NATURE, 137, 411 (1936).
2. See W. T. Astbury, Proc. Textile Inst. (1936), in the press.
3. L. Pauling and J. Sherman, J. Chem. Phys., 1, 606 (1933).
4. J. B. Speakman, Proc. Textile Inst. (1936), in the press.
5. See, for example, J. W. Baker, ” Tautomerism” (1934), p. 38.