1. Svedberg, T., NATURE, 139, 1051 (1937).
2. Svedberg, T., and Pedersen, K. O., “The Ultraccutrifuge” (Oxford: in the press).
3. Pedersen, K. O., C.R. Trav. Lab. Carlsberg, Sér. Chim., 22, 427 (1938). Steinhardt, J., J. Biol. Chem., 123, 543 (1938). Lundgren, H. P., NATURE, 143, 896 (1939). Andersson, K. J. I. (cf. ref. 2).
4. Pedersen, K. O., (cf. Jersild, M., and Pedersen, K. O., Acta Pathol. et Microbiol. Sci., 15, 426 (1938).
5. Svedberg, T., and Brohult, S., NATURE, 142, 830 (1938); 143, 938 (1939). Brohult, S., NATURE, 140, 805 (1937).