See, for example,L. Spitzer:Physics of Fully Ionized Gases (New York, 1956); Sect.2.2. This work will be referred to hereafter by the prefix Sp.
S. Chapman andT. Cowling:The Mathematical Theory of Non-Uniform Gases (Cambridge, 1952). This work will be referred to by the prefix CC.
See CC, Sect.18.5.