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NEW BOOKS
the term seems justified for the purpose. This reasoning seems all the more valid when it is realized that we also have the term “amorphous” to indicate non-crystallized material. A. C. SHEMAN. Central Laboratories General Foods Corporation Hoboken, Kelt- Jersey
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Plant Viruses and Varus Dzseases. By F. C. BAWDES. Second editiQn. xi 294 pp.; 48 illustrations. Waltham, hlassachusetts : Chronica Botanica Co., 1944. Price. $4.75. This is the second and revised edition of Bawden’s book, which was first published in 1939. It will be welcomed as the only up-to-date publication bringing together information regarding the pathology, syniptoniology, serology, and chemistry of plant viruses. T h e author is chiefly concerned with those virus diseases which have been studied most extensively, and the discussion is limited largely t o studies made since 1930. The chemist will be especially interested in the five chapters on the preparation and properties of purified virus proteins. The author is n-ell qualified t o discuss this particular phase of virus research, because niany of the important contributions in this field have originated in his o v a laboratory. I t is a R-ell-recognized fact that the application of physical-chemical methods t o the study of plant viruses during the past decade has resulted in a remarkable increase in our understanding of the nature of these rather unique substances. On the other hand, the virus proteins have benefited the study of physical chemistry by providing suitable materials for studying those phenomena relating t o viscosity, sedimentation, diffusion. and the optical properties of anisotropic flon . Chapters S,9, and 11 deal with the methods of preparation and the properties of purified virus proteins. Chapter 10, on the optical properties of virus proteins, is presented in a thorough and interesting manner. Chapter 12 discusses studies on the determination of the particle sizes of viruses by such methods as ultrafiltration, diffusion, viscosity, sedimentation, and ultramicroscopy. The author takes the viewpoint that the molecular weight of tobacco mosaic virus has not been established conclusively. This conclusion seems to be well founded in vie\%-of the available evidence showing interaction and aggregation of virus particles in solution. In the final chapter, on the nature of viruses, the author points out that it is impossible to determine whether or not viruses are living entities because the distinctions betrveen animate and inanimate matter are not clearly defined The book is well nritten and the illustrations are especially good The reviener regards this book as a valuable contribution t o the study of plant viruses and virus diseases. CLAUDEH . HILLS.
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Systematic Inorganic Chemistry of the Fifth- and Sixth-Group Soninetnllzc Elements. By D o s ?*I.TOST~ X HORACE D RUSSELL,JR., California Institute of Technology. XY 123 pp. S e w T o r b . Prentice-Hall, Inc., 1941. Price: $6.00. It has been a great pleasure to become acquainted x i t h this book and to note the niodern and even revolutionary treatment of topics in an advanced course in inorganic chemistry. The authors state, in their preface, “From these considerations it is evident that any discussion of a chemical element or compound is complete only when the spectroscopic, structural, thermodynamic, chemical kinetic, and nuclear properties have been consid-
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