1. Dutta, A. K.Acad. Sci. U.P. Bull., 1931,1, 89.
2. Watson, W. W., and Parker, A. E.Phys. Rev., 1931,37, 1484.
3. Clements, J. H.Phys. Rev., 1935,47, 220 and 224.
4. Asundi, R. K., and Samuel, R.Proc. Phys. Soc. London (in the press).
5. Cf. Stuart, H. A.Molekulstruktur, Berlin, 1934. Jenvons, W.Report on Band Spectra, London, 1932.