Key points are not available for this paper at this time.
This is a completely rewritten version of Professor Spitzer's earlier text Diffuse Matter in Space, and the result is splendidly authoritative and readable. As the change of title indicates, the emphasis of the book has been somewhat altered; there is a fuller description of basic physical processes, while the updated observational data have been presented more concisely.
Anthony King (Tue,) studied this question.