1. See preceding communication.
2. Dyrssen, D., Svensk Kem. Tidskr., 62, 153 (1950).
3. Bouissières, G., and Ferradini, C., Ann. Chim. Acta, 4, 610 (1950).
4. Picciotto, E., C.R. Acad. Sci., Paris, 228, 173, 247 (1949).
5. Picciotto, E., C.R. Acad. Sci., Paris, 228, 2020 (1949).