L Marton (ed) London and New York: Academic Press 1975 pp xi + 389 price £20.55, $39.50 The book contains specialist review articles on six disparate topics. The subjects covered are: electron diffraction theory applied to transmission electron microscopy of crystalline materials; theoretical and experimental investigation of the energy spectrum of electrons from a thermionic cathode; use of afterglows for studies of atomic, molecular and ionic processes in rare gases; the application of molecular beam masers as microwave amplifiers and oscillators and in molecular spectroscopy; development of the chargecontrol concept of bipolar transistor operation; the first part of a review of microwave power semiconductor technology, theory and applications.