It is difficult to imagine any more useful, or more instructive textbook than this. -- Transactions of the Faraday Society This book was the first comprehensive treatment of quantum physics to appear in any language. Originally published in 1936 as part of Oxford University Press's famed International Series of Monographs on Physics, this book is a classic reference text. Although new particles have been discovered since the third edition was published in 1954, its presentation of quantum physics is still relevant because the basic theory remains unchanged. Moreover, its historical perspective is unique and its physical insight substantial; thus, it remains in demand among physics professors, students, and researchers. Beginning with Maxwell and Lorentz's work, W. Heitler, in his lifetime a noted physics professor at the University of Zurich, covers seven major theoretical areas: - the classical theory of radiation- quantum theory of the pure radiation field- the electron field and its interaction with radiation- methods of solution- radiation processes in first approximation- radiative corrections and ambiguous features- the penetrating power of high-energy radiation Here is a unified and accurate guide to the application of radiative processes that explores the mathematics and physics of quantum theory. The author provides numerous examples to illustrate the conceptual material and deals with basic elements of the theory. Electrons, positrons, and radiation are all discussed as are the production, propagation, and detection of em radiation. Heitler's thorough coverage of quantum physics has earned this landmark work an outstanding reputation among physicists and the book is highly recommended as both text and reference.