1. Burn, J. H., and Rand, M. J., Nature, 184, 163 (1959).
2. MacIntosh, F. C., Birks, R. I., and Sastry, P. B., Nature, 178, 1181 (1956).
3. Reitzel, N. L., and Long, J. P., Arch. Int. Pharmacodyn., 119, 20 (1959).
4. Wilson, H., and Long, J. P., Arch. Int. Pharmacodyn., 120, 343 (1959).
5. Chang, V., and Rand, M. J., Brit. J. Pharmacol., 15, 588 (1960).