1. The first of these papers, byL. Ferrari and the author, which was also discussed at theLIV Conference of the Italian Physical Society, Rome, October 1968 (Bollettino S.I.F., n. 62, p. 15, October 1968), is being submitted for publication in this same journal. (Note added in proofs: seeNuovo Cimento,67 B, 167 (1970).) The article on the rates of electron excitations will be published in the near future.
2. S. Chapman andT. G. Cowling:The Mathematical Theory of Nonuniform Gases, Chap. 18 (New York, 1960);
3. W. P. Allis:Motions of Ions and Electrons inHandbuch der Physik, Vol.21 (Berlin, 1956);
4. J. C. Bowe:Am. Journ. Phys.,31, 905 (1963).
5. F. Reif:Fundamentals of Statistical and Thermal Physics (New York, 1965).