Biological Effects of Deuterium

introducing and removing amino acid blocking groups. Section II deals with coupling methods, and several papers take up the problem of racem-ization. Especially interesting is a report of the use of a gas chromatographic technique to compare the degree of racemization by various commonly used coupling techniques. The third section discusses the occurrence of "unnatural" amino acids and special problems involved in the synthesis of antibiotic peptides that contain such amino acids. The first chapter in this section is a valuable comprehensive review of this field with 270 references. A short fourth section briefly discusses two aspects of peptide chemistry unrelated to synthetic problems: the conformation of peptides in solution, and nonenzymic cleavage of peptides at cysteine and serine residues. The final section is the shortest, but nevertheless is a valuable contribution. It is the report of the committee on nomenclature with recommendations for a uniform system of writing formulas for amino acid derivatives and amino acid sequences. It is to be hoped that future authors will pay as strict attention to these rules as have the contributors to this particular volume. A book of this type, in spite of its excellent organization, must, by its very nature, be somewhat of a potpourri of information. This does not detract form its value. A great deal of interesting and useful chemical information is presented in a limited space. The book is certainly to be recommended as a valuable reference for anyone actively interested in synthetic peptide chemistry. This is volume 19 of the International Series of Monographs on Pure and Applied Biology. The majority of reactions studied relate to the use of D20 ("heavy water"). A sequential presentation of the actions of this compound is given, beginning with physical aspects, progressing through enzymatic reactions, effects on microorganisms , lower animals and plants, and ending with effects on intact mammals. A brief chapter on the relationship of D20 to radiation sensitivity of biological objects emphasizes the contradictory nature of the results in this area. This volume represents a review of the literature and contains an author and subject index. This is a very short history of biology and suffers from some of the faults inevitable within such confined limits. Over the broad ranges of history extending from antiquity to the seventeenth century the author's treatment is impressionistic, superficial, and heavily indebted to such older histories as those of Singer and Nordenskiold. The …