provided for each group. The analysis of general unknowns requires the separa, tion of the groups and the order of separa, tion is tbe reverse of that followed in the study of the individual groups. The book is concise and the working directions are good. I t is a good manual for those courses where qualitative analysis is given as part of freshman chemistry.
Diamagnetism and the Chemical Bond
Ya. G . Dorfman, Leningrad State University. Translated by Scripta Technica. Trans. ed. by Chmles P. Poole, Jr., University of South Carolina, Columbia. American Elsevier PublishingCo., Inc., New York, 1965. x 182 pp. Figs. and tables. 14 X 22.5 cm. $10.
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LESTEEK I E ~ Although diamagnetism is a universal Bucknell University property of matter, interest in applying Lewisburg, Pennsylvania diamagnetic susceptibility to chemical problems bas much diminished since World War 11. One reason is that ESR techniques give the paramagnetic component for substances with unpaired electrons directly without the necessity of correcting for the underlying diamagnetism as must frequently be done when employing static susceptibility measurements. Very reOfRcial Methods of Analysis of the cently there has been s. slight revival in Associdion of Official Agricultural structural diamagnelism, probably beChemists cause of its close connection with NMR ehemical shift. Edited by William H d z , chairman, and Peter Chichilo, Paul A. Cliffwd, The product of this revival has been the and H e l a Reyzolds. Association of Ofpublication of two brief monographs each ficial Agricultural Chemists, Washingdescribing a semiempirical system for calton, D. C., 1965. 10th ed. 957 pp. culating diamagnetic susceptibilities of a Figs. and tables. 18.5 X 26.5 cm. wide variety of substances. One of these $22.50. is Dorfman's book. Orgindy published in Russian in 1961, it appeared in a GerThis is s book of stmdrtrd methods for man translation in 1964 and now in a the analysis of foods, drugs, cosmetics, slightly revised English edition. (The and a wide variety of agricultural prodother monograph, by Haberditzl, was pubucts. Each analytical procedure has been lished in East Berlin in 1964.) adopted only after it has been proved to he According to quantum mechanics the reliable and to give reproducible results measured diamagnetic susceptibility, X , is in an officially oonduoted collaborative composed of two terms: a usually sizeable study among several different laboratories. negative one, the "Langevin diamagne The standard methods thus established tism" corresponding to that obtained from are used in the enforcement of legal classical theory, plus s. small positive regulations and they serve both industry term, the "Van Vleek," or temperatureand government as a basis for specificaindependent paramagnetism, such that tions. Established methods are also of x = xo XP. I t is the latter term which value in research work in which c e d i n would he the principal structure-sensitive quantities can be precisely defined only factor were it accessible to direct calculsi work in which certain quantities can be tion or separate measurement. Dorfprecisely defined only in tenns of an man's scheme depends upon the use of analytical method. The significance of Kirkwood's relation between xD and molar data on the fiber content of feed, for polsriaability to obtain xp by difference. example, depends directly upon a standard Thus two experimental parameters are method for fiber determination. needed, the measured diamagnetic suscep This 10th edition is 125 pages larger tibility and the refractive index. than the previous (1960) edition. (See Dorfman reviews the data and cancluTKIS JOURNAL, 38, 431 [August, 19611.) sions he has d r a m from the application of New methods appesr chiefly in the areas of his method in four of the hook's seven pesticide residues, drugs, and food adchapters. These deal with ionic suhditives reflecting the greater emphasis now stances, covalent compounds with single being placed on potentially bwardous and multiple bonds, aromatic compounds, materials. Notable additions to the s e e anisotropy, coordination complexes, and a tion of fertilizers are the quinaline molybbrief treatment of nuclear resonsnee. date method for determination of phosAlthough some of the correlations are phorus and the use of atomic absorption ingenious, the method does not seem wellspectroscopy for the determination of enough developed to make its use as a minor nutrients. Very few new methods structural tool reliable. The theory is have been adopted in the areas of food very "elastic" and-though an improvecomposition, flavors, preservatives, vita, ment upon the purely empirical increment mins, colors, and cosmetics. system of Pascalkatill admits too many For those who sre concerned with enrtdjwtrtble factors for various types of forcing or complying with regulations this volume is s, necessity. It should be of some value in educational libraries as a reference for information on orocedures properties. Parenthetically, it may be and methods currently used in'an impornoted that the Elaberdital method seems to tant field of analytical chemistry. be somewhat more refined and applicable LOYALR. STONE to a wider variety of organic compounds, a t least. Hess & Clark Ashland, Ohio The present volume suffers from two
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specific flaws in the reviewer's judgment First, there is no appraisal of experimental methods used in gathering either the sue ceptibility or polsriaability data used in spite of the fact that deviations are sametimes exolained awav on the basis of experimental innccumry. Thi*. Iruaever, in a matter of judgment, rsidinp, pmly perhaps, in the edirorixl policirri of Soviet publishing houses. What is much less defensible is the la& of attention paid to the proper use of significant figures in the results of calculations contained in the extensive tabulations. Especially &grant abuses are to be found on pp. 56, 74, and 90, but there are too many other examples all through the books. Since the important structural datum is often the difference of two sizeable numbers, this csrelessneas decreases the usefulness of the work greatly. It seem inexcusable in a book now appearing for the third time. Other errors of fact are found on D. 70 (inwmromir diptanres and dissociation enprgiw of HCI and DCI), p. 83 tpolnrity of (:(:la hundr), and on pp. I I G 7 the lacof pentavalent carbon leads the author to wrong canelusions based upon wrong formulas. There appears to be a logical inconsistency in the author's extrapolation method for obtaining experimental values of susceptibilities of organic gases. The bibliography contains minor errors including the reference to the key to Dorfman's whole system, the 1932 paper of Kirkwood. Typography is good except that mathematical material is set in such a line, spidery type that symbols with subscripts are difficultto read without m a d c a t i o n . In summssy, this is a book tnly for the large general library. Even the specialist is warned to use the data with caution; he will have to reealeulste much of it in order to assess its precision. However, in these days of research fads and "hot" topics, it is fascinating to read an account, o c w sionally, of a field which is extremely inactive!
JUDSON L. I ~ m a liniversity of Hawaii Haolulu
Molecular Symmetry: An Introduction to Group Theory and Its Uses in Chemistty David S. Schonland, University of D. Van Southampton, England. Nostrand Co., Ltd., New York, 1965. 298 pp. Figs. and tables. 16 X xii 23.5 cm. $12.
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Those using Cotton's familiar book (See JOURNAL, 41, 113 119641) on group theory as a text ought to take their lectures from Scbonland! The two supplement eaoh other nicely, as a comparison of them quickly shows. Neither book suffers for the comparison. The book by Cotton is appealing because of its intuitive approach, and its emphasis on applicetions to chemical problems. Appearing a t a time when there were few THIS
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