graduate student commencing research in this field was compelled to search out the primary sources for most of this information. In addition, the copious references should be of value to individuals not yet well-acquainted with the polymer structure literature. In this context I think that the book is a useful acquisition for any institution engaged in sueh research. I t is suitable as areferenee text far a course in polymer structure although many points will require further clarification. Use of this book as a textbook is not recommended due to its limited view of polymers and to the author's tendency t o present as standard methodology his own practices even when they differ sharply from those of other equally well-qualified investieators. The need for a book sueh as this one " is clear; the fundamental idea is sound, but the execution is lacking in many areas. William T. Winter Polytechnic institute of New York Brooklyn. NY 11201
have provided a much more detailed picture of the resin structure and chemistry. There has been substantial growth in the use of the resins in the oarticle board and insulation induvtriesand there has heen much mtrraction between U-l: rrsin pndurers and trsm on rhc one hand and government regtrlatury agencies and consumer groups on the other. Dr. Meyer's book is written as an interdisciplinary hook that attempts t o bring the subject up to date for "all those who come into contact with urea-formaldehyde resins or urea-formaldehyde resin bonded products," including scientists, regulators, arehitects, consumer advocates, and husiness people. It contains chapters covering the history, chemirtry, manufacture, analysis. proprnies,and rippliratiunaofI'-F wain9 in addition tochapters dealing with henlth and environmental aspects and future trends. A 65-page bibliography and a 16-page patent index that is keyed to the bibliography provide an indication of the scooe of the coverare. Much attention has bekn riven to the hydeand to the prevention of formaldehyde release from U-F products. Since the scope of the work is broad, the presentation of any individual topic is necessarily crisp. Although the book d o e create a general impression about each particular tooic.. it is mostlv useful as a euide to other literature. Many chapreriare written almust ~ Annual in t h e s t y l e u f . 4 n o l ) r i t o l R u ~ i r u .or Reoortr of rhr ( ' h w , ~ r . o lS m e t ) and the reader is often referred to another text on the subject for detailed information. Sometimes the details that are provided are not explained adequately. This is particularly true of the Figures. This hook belongs in the library of every organization dealing with polymers. Individuals directly concerned with urea-formaldehyde resins will find it very helpful. It contains several well-written historical sections and an analysis (p. 228) ofthe psychology of current public attitudes toward chemical oroduds that would be useful to chemistry teachers, hut it will probably not otherwise he useful to them. H. J a m e s Harwood Institute of Polymer Science University of Akron
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Urea-Formaldehyde Resins N. J. Tuno. BenjaminICummings, Menlo Park. CA. 1978. 628 pp. Figs. and tables. 17 X 24 cm. $23.95. Urea-formaldehvde resins. have been known for nppmximntelg 100 years and haw served mankind in dlvcrrc uaya for the last 60 years. h i a l l y develuprd assuhst~ruteafor glass, and used subsequently as adhesives and as components of laminates, molding compositions end polymeric foams, these polymers must be regarded with a certain amount of nostalgia because of the role they played as the "space age" materials of the past. Ureaformaldehyde resins were used t o make the translucent lamp shades on U S . railway coaches, while U-F foams were used t o insulate the smoking salon on the dirigible Zeppelin, and U-F adhesives were used in the construction of torpedo boats, propellers, and the Mustang fighter during World War 11. Today, these resins are being used to solve problems that have developed because of dwindling natural resources and because of our concern for ecology. Thus, the largest use of these resins today is in the construction of particle board, a valuable product based on forest wastes. In addition U-F foams can he used to absorb oil spills, for home insulation, and in "plastoponics"-a new field which involves gardening in plastin. Unfortunately the tendency of U-F resins to release gaseous formaldehvde has led to concern about the puapihlz health l w a r d r nswrinted with U-F particle hoanl and insulnting t'cnm in hcmr construction. The most recent books covering the chemistry, technology, and applicationa of U-F resins were written more than fifteen years ago and much has happened during the interim. New analytical techniques such as Raman spectroscopy, thin-layer and high pressure liquid chromatography, differential ~
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A380
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Journal of Chemical Education
Akron. OH 44325
Symmetry Groups Theory a n d Chemical Applications R. L. Flurry, Jr., Prentice-Hall Inc.. New Jersey. 1980. 356 pp. Figs. and tables. 18 X 24 cm. $26.50. Flurry intended this book to shield students from feeling that they have been "run throueh" after their first encounter with smudthenrv. Unfortunatelv. this shield has ~~~~~~,~ some holes in it. The book covers too much material tw briefly for its intended audience. The Preface Suggests two ways of reducing the coverage, depending on whether theemphasis of the course is group theory or its chemical applications. However, even the latter alternatives has more theory and more diverse applications than the books by F. A. Cotton, D. S. Sehonlsnd, and D. M. Bishop. ~
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group theory.;nder the headingssymmetry and Groups (Ch. 2,17 pp.), Point Symmetry (3, 13 pp.), Space Symmetry (4, 17 pp.), Irreducible Representations of the Symmetry Groups (5,27 pp.), and Some Special Groups (6,35 pp.). The special groups are the threedimensional rotation-reflection group, the double groups, the symmetric permutation group, and the symmetry groups of nonrigid molecules. The next two chapters, Quantum Mechanics (7, 27 pp.) and The Interaction of Radiation and Matter (8, 20 pp.), are intended as a bridge between the group theory and its applications. Flurry states in the Preface that neither of these chapters is intended to teach a student the material in it. He says they can be omitted, except for a few key sections. However, he is hedging here on his claim that the book should be comprehensible to anyone whose background includes introductory chemistry and physics. On the other hand, many students will appreciate having all relevant material included in one volume. The final five chapters contain 117 pages of applications: Atoms and Linear Molecules (9, 29 pp. including crystal-field theory), Electronic Structure and Spectra of Nonlinear Molecules (10, 32 pp.), Vibrations of Nonlinear Molecules (11, 25 pp.), Rotational States and Nuclear Spin States (12,pp.),and Symmetry Control of Chemical Reactions (13, 13 pp.). Chapter 9does not show how to predict electron configurations or vibrational modes for linear molecules. The approach in Chapter 13 is unusual but highly successful. For reasons given under Concluding Remarks, applications of space groups and the groups of nonrigid molecules were slighted intentionally. The hook has six appendices: (1) Notation and Nomenclature, (2) Sehur's Lemma and Wigner's Grand Orthogonality Theorem, (3) Answers to Selected Exercises. (40Correlation Tables, (5) Character ~ a b l e sand (6) Glossary. There are 64 problems grouped a t the ends of the chapters. In addition, there are 62 exercises dispersed in the chapters, with answers to 28 of them in Appendix 3. The placement of some of the exercises is poor. Exercise 1.3 on page 7 asks far the projection of a vector. but the oroiection omrator is
~nrludlngImprc,per ratatlons and i n v e r w n through the renter, whxh are drbned in Chaptrr 'I Alro, HR IS a poor exampir hrre b e c k s e reflection in the molecul& plane appears to be the identity operation unless the tops and bottoms of the atoms are distinguished. Try PFb instead. A few typographical and factual errors were noted. The answer to Exercise 1.7 (b) has lost a minus sign in the origIRal vector. Prohlem 2 of Chapter 11needs 4 CI- rather than 3. A better choice for the central ion here and in problem 3 of Chapter 10 is Pd2+ or Pt2+, because NiC142- is Td,not Dlh. Page 207 says that the s orbitals in Hg transform as a constant, but they do not. On pages 22P225, Flurry attempts to predict the order of the energy levels in methane using tetrahedral hybrid orbitals. He mistakenly says that the hybrids arenonorthogonal, and thus
he appears to remove the degeneracy of the hybrida, - tz orbitals. Flurry defines symmetry operations to be eavariant with respect to the implicit caordinates of the atoms in a molecule, but contravariant with resoect to the coordinates of
ecule to combine in reverse order to the operations themselves. He uses the same symbol for both row and column matrices of vector components, as well as far the vector itself. This usage is confusing, and it is critical because it cannot be indiscriminate. For erample, a ruw \rctor m.lsr he used m his cuntrdwriant avnlmrrr! upcralions, hut a c d . umn vector inus he u.cd in his projection operator where the same symbol appears. On page 24, Flurry is careful to point out that "Symmetry operations are not the same as symmetry elements."Therefore, symmetry operations are called symmetry elements reueatedlv. as in four nlaces on uaee 28.
way he prefers is the sitesymmetry method, which appears to be more complex in principle and no simpler in practice than direct use of the point group. Readers who wish tojudge for themselves can read Flurry's article, "Site Symmetry and Hybridized Orbitals," J. CHEM. EDUC., 53, 554 (1976), which coincides almost verbatim with pages 217-222 of his hook. In conclusion, instructors who assign this hook should be prepared to warn, guide, and encourage their students through selected portions of it. J a m e s L. Bills Brigham Young University Provo, UT 84602
Qualitative Analysis of Flavor and Fragrance Volatiles by Glass Capillary G a s Chromatography Walter Jennings and Takayuki Shibamofo, Academic Press, New York. 1980. vii 472 pp. Figs. and tables. 20 X 24.5 cm. $39 00.
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"Qualitative Analysis of Flavor and Fragrance Volatiles by Glass Capillary Gas Chromatography" describes a range of practical ancillary techniques that are useful adjuncts to capillary gas chromatography. It features the retention indices of about 1200
. . . .. . uiil phnws. l n d ~ c earc j prrsented in alphah r t al ~ d~ e r of compounds which are rru,sindexed by most comm
