Today, our world increasingly is conceived of as being molecular. An ever widening range of phenomena are described logically in terms of molecular properties and molecular interactions. The majority of known molecules are heterocyclic and heterocycles dominate the fields of biochemistry, medicinal chemistry, dyestuffs, photographic science and are of increasing importance in many others, including polymers, adhesives, and molecular engineering. Thus, the importance of heterocyclic chemistry continues to increase and this three volume work by Drs. R. R. Gupta, Mahendra Kumar and Vandana Gupta is a welcome addition to the available guides on the subject. Its scope places it in a useful niche between the single-volume texts and monographs of heterocyclic chemistry and the multivolume treatises. The authors have retained the well tried classical approach but have succeeded in placing their own individual spin on their arrangement. They have put together a well selected range from among the most important of the vast array offacts available. This factual material is ordered in a clear and logical fashion over the three volumes. The present work should be of great value to students-and practitioners of heterocyclic chemistry at all levels from the advanced undergraduate upwards. It will be of particular assistance in presenting a clear and modem view of the subject to those who use heterocycles in a variety of other fields and we wish it well.

Nuclear Magnetic Resonance (NMR) is based on the fact that certain nuclei exhibit a magnetic moment, oriented by a magnetic field, and absorb characteristic frequencies in the radiofrequency part of the spectrum. The spectral lines of the nuclei are highly influenced by the chemical environment, i.e. the structure and interaction of the molecules. NMR is now the leading technique and a powerful tool for the investigation of the structure and interaction of molecules. The present Landolt-Bornstein volume III/35 "Nuclear Magnetic Resonance (NMR) Data" is therefore of major interest to all scientists and engineers who intend to use NMR to study the structure and the binding of molecules. Volume III/35 ''NMR-Data'' is divided into several subvolumes and parts. Subvolume III/35A contains the nuclei B-11 and P-31, subvolume III/35B contains the nuclei F-19 and N-15, subvolume III/35C contains the nucleus H-1, subvolume III/35D contains the nucleus C-13, subvolume III/35E contains the nucleus O-17, subvolume III/35F contains the nucleus Si-29, and subvolume III/35G contains the nucleus Se-77. More nuclei will be presented later.