1. Brownrigg, William, Phil. Trans. Roy. Soc., 49, 534 (1756–7).
2. Kronberger, H., First Intern. Symp. on Water Desalination, Washington, 1965.
3. Parsons, J. A., O.R.N.L. 3962 (1966).
4. Lacey, R. E., Lang, E. W., and Huffman, E. L., Adv. Chem. Series, 38 (1962). See also ref. 7, p. 280.
5. Thau, G., Bloch, R., and Kedem, O. (in the press).