This book, first published in 1956, represents a notable contribution to the literature of atomic and molecular structure. As the title implies, the contents are limited to an account of beams of electrically neutral particles. The use of molecular-beam resonance techniques encouraged an increasingly precise study of radio-frequency spectra of atoms and molecules. These measurements have led to a wealth of precise data. The introductory section of the book gives us a preliminary survey of experimental apparatus and the kinds of quantities that can be measured. Subsequent chapters give comprehensive accounts of gas kinetics, chemical equilibria, and atomic and nuclear magnetic moments are included, as well as detailed accounts of nuclear and molecular interactions. Finally there are sections on atomic fine and hyperfine structure, and the design of experimental apparatus.