1. C. F. Powell:Phil. Mag.,44, 219 (1953).
2. M. Teucher: private communication for example.
3. Mees:Theory of the Photographic Method, (London, 1954), pp. 709 ff.
4. B. Stiller, M. M. Shapiro andF. W. O’Dell:Rev. Sci. Inst,25, 4, 340 (1954).
5. A. H. Rosenfeld et al.: How to Develop Emulsion. Privately circulated manual from the Institute of Nuclear Studies, Chicago.