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
