In recent years high-resolution nuclear magnetic resonance spec- troscopy has found very wide application in organie chemistry in structural and physicochemical investigations and. also in the study of the characteristics of organic compounds which are re- lated to the distribution of the electron cloud in the molecules. The vigorous development of this method, which may really be re- garded as an independent branch of science, is the result of ex- tensive progress in NMR technology, the refinement of its theory, and the accumulation of large amounts of experimental material, which has been...