1. Hoar, T. P., and Evans, U. R., J. Chem. Soc., 2476 (1932).
2. Evans, U. R., J. Chem. Soc., 1030 (1927).
3. Mears, R. B., Carnegie Scholarship Memoirs, 24, 69 (1935). Compare C. E. Homer, Iron and Steel Inst. Corr. Comm. 2nd Report, 225 (1934).
4. Mears, R. B.,and Ward, E. D., J. Soc. Chem. Ind., 53, 382T (1934).
5. Evans, U. R., Iron and Steel Inst. Corr. Comm. 5th Report, 225 (1938).