1. Bowden and Hughes, Proc. Roy. Soc., A, 160, 575 (1937).
2. Hardy, "Collected Works" (Camb. Univ. Press, 1936).
3. Sameshima et al., Bull. Chem. Soc. Japan, 11, 659 (1936).
4. Beare and Bowden, Phil. Trans., A, 234, 329 (1935).
5. Bowden and Leben, Proc. Roy. Soc., A, 169, 371 (1939).