The unusual approach of this text gives final honours and post-graduate students a clear and explanatory account of one of the "harder" areas of physical chemistry. The author takes care to provide detailed verbal clarification of the concepts and their importance together with full explanations of the mathematical developments. Her explanations are an essential and vital feature of the text, which is scholarly, lucid and well-written with a combination of depth of coverage and clarity which helps students to work through on their own.