In the short time since the first nitroxyl radical was obtained in 1959, a new branch of chemical science has arisen and taken shape-the chemistry of stable nitroxyl radicals. The present book was written by E. G. Rozantsev, one of the pioneers in this field and a prominent specialist on stable radicals at the Division of Chemical and Biological Processes of the Institute of Chemical Physics, Academy of Sciences of the USSR. His numerous papers have contributed greatly to the present situation, wherein nitroxyl radicals have acquired unusually wide popularity, including the fields of biology, medicine, chemis­ try, physics, biophysics, and instrument construction. A clear illustration of the astonishingly vigorous development of this new field of chemistry can be given by the enormous flow of information on the synthesis and use of nitroxyl radicals. There is no doubt that this monograph, which in part generalizes the results of many workers studying these radicals, will be received with interest by specialists working in this field. The author has not attempted to give an exhaustive account of the material. His aim is to introduce the reader to this new field and to show the wide possibilities for using radicals in scientific experiment. The voluminous bibliography, including many papers by the author himself which may not be well enough known to the American reader, will undoubtedly contribute to the usefulness of the monograph.