1. Rose, H. E., Trans. Inst. Chem. Engnrs.35, 87 (1957).
2. Nijman, L. J., Brit. Chem. Eng.3, 76 (1958).
3. Andreasen, A. H. M., paper read at the Meeting of I. M. Eng., London, 7th November 1956.
4. Berry, C. E. andH. J. Kamack, Proc. 2nd Intern. Congr. Surface Activity4, 196 (1957).
5. Nijman, L. J., Brit. Chem. Eng.3, 414 (1958).