Abstract :
Electrical properties of mercury vapor and monatomic gases are discussed from a theoretical standpoint in this article. In the first part of the article, the author discusses briefly the elementary processes of excitation and ionization of atoms upon which the electrical properties of gases depend. With this insight into the fundamental processes as a background, the author discusses in Part II the electrical conductivity of gases under various conditions. This is the eleventh in a series of special articles prepared under sponsorship of the A.I.E.E. committee on education.