1. Stein, W. D., The Movement of Molecules Across Cell Membranes (Academic Press, 1967).
2. Kobb, W. L., et al., US Patent, No. 3,355,545.
3. Ward, W. J., and Robb, W. L., Science, 156, 1481 (1967).
4. Ward, W. J., AIChE J. (in the press).
5. Taub, I. A., thesis, Univ. Minnesota (1961).