previously in Chapters 5, 7, 8 and 9; Chapter 6 (14 pp.) describes the techniques of distillations; Chapter 7 (Behevior of Solid Substances, 16 pp.) has revised material formerly in Chapters 14 and 15; Chapter 8 (Techniques of Preparation of Solids, 16 pp.) has topics previously in Chapters 12 and 13; Chapter 11 (Solubility of Organic Compounds, 10 pp.) now follows the discussion of extraction, adsorption and chmmatography in current Chapter 9 (16 pp.); Chapter 14 (The Literature of Organic Chemistry, 8 pp.) is longer and better than its earlier counterpart; Chapter 15 (Writing of s Research Report) is comparable t o Experiment 56 (Library Problem) of the previous edition. The revision of Part I1 (Laboratory Experiments) seems to be less extensive than that of Part I, although many changes have been made. Notable additions to Part I1 are Experiments 8 and 44 on chromatography. In Experiment 44 is a list of 18 dyes approved far use in foods, drugs and eosmcties. Experiments deleted from Part I1 are alcohol b y fermentation, derivatives of nitroparaffins (cxeept acetoxime) and preparations of crystal violet and n-but,vlbenzene. The section on qualitative organic analysis has been improved by expansion. Although the section on literature references tn special preparative experiments is similar t o its predecessor, some interesting additions are preparations of triallylamine, n-hexyl fluoride, i-anthral2,4,6-tri-terl-butylphenol, 2dehyde, iodothiophene, ferroeene and n-butyllithium. Bccause this manual has so many assets, i t merits the attention of everyone who is interested i~ the teechina of organic chemistry in the labarator< DONALD C. GREGG University of Vennont Burlington
Theory of Molecular Excitons
4 . S. Dauydov. Translated by Michael Kasha, Florida Stabe University, Tallabhasee, and i M u Oppenheimw, JT., State University of Iowa, Ames. McGrew-Hill Rook Co., Inc., 1962. 174 pp. Figs. and tables. 16 X ix 23.5 cm. $7.95.
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The translation by Kasha and Oppenheimer of Professor Davydov's fairly old Russian book is an extremely welcome addition t o the English speaking literature. The hook represents the treatment of Davydov's contribution t o the theory of molecular spectra, in particular, his approach t o treating molecular spectra as excitons. This is a very useful concept, not only in t h e field of the spectra of solids, but in many related fields which involve the transmission of excitation from one site to another in a solid. Unfortunately, the fact that the vast majority of the literature concerning this area is in Russian has had the effect t h a t it is little understood, and little used in the English speaking world. The availability of the translation of Professor Davydov's
A142 / Journol of Chemical Education
book should do much to overcome this difficulty. The book is not easy to read. I t is a highly m;tthernatical treatment, and many precticing chemists will find it far beyond their comprehension. It is addressed t o the specialist; it is understandable really only to him. One can certainlg not recommend i t to the average chemist for rapid reading or scanning, although, the theoreticd physical chemist. with interests in spectrwcopy will probably find i t a must. The usefulness of the book is greatly enhanced by two appended bibliographies: 1, the papers of Davydov's following the publication of the book, containing some 57 entries, and 2, a bibliography of publications on excitons, mostly from the western world, with ahbout forty entries. The book is well made, a& tractively bound and, for the very small market, docs not appear exeessivcly expensive.
H. H. JAFFE University of Cincinnati Cincinnati, Ohio
Absorption Spectra a n d Chemical Bonding in Complexes C. K. Jdrgensen, Cyensmid European Research Institute, Cologny, Geneva, Switzerland. Addison-Wesley Publishing Co., Inc., Reading, Mass., 1962. xii 352 pp. Figs. and tables. 14.5 X 22.5 em. $10.
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We now know how to interpret a t least the gross features of the absorption spectra of complexes of the transition metal ions. Furthermore, while the study of these spectra has usually been aimed a t clarifying the electronic structures of the several metal ions, a parellel reward has often been an insight into the nature of the various ligands. This book attempts to survey these areas of inorganic chemistry with the ultirnrtte aim of summerising current ideas on the nature of the chemical bond in complexes. The author is only partially successful, however. The book could certainly not be an introduction to the field for the untutored; it is far too concerned with controversies t o be a useful textbook. Yet, it is not deer for whom the boak wss designed. Thus, the first chapter i s a historical introduction not only t o bonding in complexes, but t o the bonding in 811 chemicals. The second chapter follows with a discussion of the application of density matrices! Certainly this is an uneven level of sophistication, chsrscteristic of much of the book. Jdrgensensummarizes much of the availsblc data and discusses and criticims the various theories and internretations of
series, nephelauxetic eeries, electron transfer spectra, and so on. The boak is an excellent reference for the specialist in the field, for some 950 references are liated, along with a large number of spectral results and electronic
parameters included in some 34 tables and 29 diagrams. Further, Jdrgensen is prulifie and highly original in his intaresting suggestions for new research. A chapter discussing the methods of detannining stability constants in solution is included as is also a discussion of the solution chemistry uf the metal ions; tbesc chapters soem out of place here. $11 in d l , this book will be of use to the worker in the field as a reference, but of ratherlimited general appeal. RICHARD L. CARLIN Brown University Pmvidenee Rhode Island
Direct Analysis of Diffraction b y Matter
8.Hosemann, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Berlin, and S. "v'. Hagehi, University of Calcutta, India. North-Holland Publishing Co., Amsterdam, 1962 (distributed in U S . by Interscience Publishers, Ine., New York). xni i 3 4 p p . Figs. and tahles. 16 X 23 em. 121.i5.
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This book is concerned with the prohlctn of deriving the atomic arrangement in matter hy direct interpretation of information obtained through the diffraction of X-rays, electrons, or neutrons. Direct methods, as opposed to triwl-anderror methods and other indirect prc,cedures requiring the application iuf human ingenuity and judgmmt, have long been sought after hy X-ray crystallographers, but except in rertain favorable cases the end of the search is not in sight. I n X-ray crystallography the at,nmic arrangement is often found by use of the Patterson function, which is calculated by means of a Fourier series in which the squares of the diffraction amplitudes appear as coefficients, no knowledge of the phases of the diffracted wnves (which are inaccessible to direct experiment) being required. The Patterson function is the "'folding" or "convolution product" of the electron density funrtion, and the h t t e r is a "folding root" of the Patterson function, obtained by some "deconvdution" procedure. In general there exist an infinite or quasi-infinite number of folding roots of s. given Patterson function: to obtain a unique root it is necessary to introduce restrictions on the numbers and shapes of the atoms present, based on chemical and physical knowledge. This amounts to treating the Pattenan function as being composed of a. finite number of charneteristie peaks, each corresponding to the interatomic vector between two atoms.
Erratum: With Mark Twain, C. W. Wood can say that the report of his death was greatly e x a g g e r a t e d . Mr. Wood, identified in s, book review caption of the November JOURNAL (page A906) as "deceased" is very much dive. We regret any embarrassment we may have caused him or his family.
