1. Osmond, R. G., Owers, M. J., Healy, C., and Mead, A. P., Atom. Energy Res. Est., Harwell, AERE—R2899 (1959).
2. To be published.
3. Glendenin, L. E., and Metcalf, R. P., National Nuclear Energy Series, 9, Book 3, 1625.
4. Morgan, A., Rundo, J., Vandervell, H. D., and Emeleus, V. M., Nature, 193, 1150 (1962).
5. Cambray, R. S., Fisher, E. M. R., Spicer, G. S., Wallace, C. G., and Webber, T. J., Atom. Energy Res. Estab., Harwell, AERE—R4094 (1962).