1. Clarke, N. C. (1924). Amer. J. med. Sci., 168, 201.
2. The Action and Uses in Medicine ofDigitalis and its Allies;Cushny, A.R.,1925
3. Eggleston, C. (1915). Arch. intern. Med., 16, 1.
4. Eggleston, C. and Wyckoff, J. (1922). Ibid., 30, 133.
5. Evans, W. (1940). Brit. Heart J., 2, 51.