The Nature of the Chemical Bond provides a general treatment, essentially nonmathematical, of present (as of 1960) knowledge about the structure of molecules and crystals and the nature of the chemical bond. Among the new features in the third edition are a detailed resonating-valence-bond theory of electron-deficient substances, such as the boranes and ferrocene; a chemical theory of the electronic structure of metals and intermetallic compounds; a discussion of the role of the hydrogen bond in the structures of proteins and nucleic acids; the electroneutrality principle; and other new principles of molecular structure. Linus Pauling was Professor of Chemistry at the California Institute of Technology, and a recipient of both the Nobel Peace Prize and the Nobel Prize in Chemistry.