1. H. Bieltz, J. Phys. Chem. 30, 527 (1899); Ann. 359, 42 (1908).
2. E. Ch. C. Baly and W. B. Tuck, J. Chem. Soc. 89, 982 (1906); C. 1906, II, 495.
3. M. P. Grammaticakis, Bull. 14, 438 (1947).
4. E. Bamberger and W. Pemsel, Ber. 36, 56 (1903).
5. E. Fischer, Ber. 29, 795 (1896).