THE scope of the present discussion is essentially the same as that established in the first review of inorganic microchemistry (314). Most of the references to developments in such fields as polarography, light microscopy, electron microscopy, fluorometry, nucleonics, and spectrometry are left for more detailed discussion in accompanying reviews, although strictly speaking, they represent true examples of important microchemical techniques. Likewise, most of the developments of applied microchemical methods are left to the reviews of analytical progress in the various industrial fields. BOOKS AND REVIEWSProgress in any field is greatly influenced by the appearance of authoritative books. A noteworthy contribution in the field of microchemistry is the recent appearance of the book "Specific, Selective and Sensitive Reactions" by Feigl (72). This book is unique in that it is an unusually complete record of the profound knowledge and experience of its author; it is not a mere abstract of collected papers but is a critical development of chemical theories based on intimate knowledge of the literature of analytical chemical researches. The book deals mainly with the chemistry of coordinated compounds, including such topics as complex ions and molecules, organic reagents, masking and demasking, induced and catalyzed reactions, surface effects, fluorescence, and photoreactions. No corresponding material has ever been presented in one place before and it seems safe to say that there is no one in the field of microchemistry who could not profit through