BOOKREVIEWS
April 5 , 1033
rent research in this area. I n addition, it has a definite “how to do it” flavor; there are numerous examples to illustrate the working of the theory and a whole chapter on methods of solving the secular determinant from \rIiich the vibrational frequencies of a molecule are calculated. A complete sample analysis of the benzene molecule is given. It is, therefore, a book which should certainly be in the hands of every student beginning work in molecular spect roscopy. T h e main criticism of this excellent work is that the chosen subject is in some \rays too narrowly limited. The analysis is formal and very little attempt is made to give physical feeling for the problems. Furthermore, very little consideration is given to the problem of proceeding from observed spectra to the calculations. Since in spectra the molecular vibrations always occur in vibration-rotation bands, it may be impossible to assign these bands correctly or even to obtain the correct vibrational frequencies without understanding the rotational fine structure. I n this conncction a comparison with Herzberg’s well knoivn book is inevitable. Fortunately, t h e two are valuable supplements to each other, the preserit work giving a clearer and more comprehensive trentineiit of the problems of symmetry and vibrations, Herzberg giving a broader view of the problems of infrared and Raman spectra. Both of these books suffer from a lack of discussion of the principles involved in the interpretation of the spectra of molecules which are too large or complicated to be treated formally. Such a discussion does not yet seem to be available anyn.Iiere in the literature, yet most published spectra are in this category, and this lack may decrease t h e w l u e of this book to “practical” spectroscopi3ts. Severtheless, this is a masterful pre.;entXtioii of the problem of niolccular vibrations and the utilizatioii of symmetry through group theory. I t sliould be on tlie reference shelf of every molecular spectroscopist arid ought to be required reading for anyone begiiining to use molecu1,ir spectra. ~IETC.ILF RESEARCH LABOR.ITORS BROWSYSIVERSITY DOSALDI;. HORSIC PROVIDESCE 19, RHODEISI.ASD
1519
nisin given for the uninhibited rc,ictioii depends upon a tcrminatiou step C1
+ C2H,Ci = CzHjC1 + HC1
which must occur to the substantial exclusion of all other termination steps betweell the three radicals C1, C,H,CI and C2H3Cl:. The mechanisni for the inhibited reaction depends upon the steps
CZHjClz CzHIC1
+ C3H6 C:IlrCIz + CdHs + CjHd = C:HsC1 + CjH,
being doininant over
+
+
HCI CjHs Cl CjHd I t seems improbable that chlorine atoms C a l i .iz,uiile such varied importance as a chain-bmikiiig reactant in the two regions. The author tot.illy ignores thc cxisteiice of tlicse problems. Tlie scrious student will be f u r t l i t ~cLillfuhed by the occurrence of tlirer iiiajor misprints i n tile >te.idy-state equation ( p . 14s). The author has einbr,iced recent ivorli of S . 13. Sl.rtcr on unimolecular re:ictioiis :is represciitilig c i uniquely rc.,ili.;tic theory of these processes. His rntliusi.i~iu i i i tliis ni;itter must be somenh;it surprising to S1:iti.r I i i i i i s ~ ~ l\\-lie f, is still westling with the m;itlieni:itic,il prol)lciiis iiiv,)l\-cil i i i developmeiit of his theory. For ex:iiiiple. tlie fir.ct quniitiitn theory treatment \vas published aftcr the I m i k u i i t l v r revietv lidd gone to press. The pliysiwl priricdI 1x1rameters being used to sumrn:iriLc t l i c rclev.ilit inforinat i n n in scores of unkno~viivibr;iti(rii frcqueiicie> .ind tr‘in2ritioii probabilities, and the niore oiic accqits tlie Slatcr tlieory ;i? representing ultimate reality, the iiiorc l i t , niust h e iiiiprvssrtl with the merit of the e:irly intuitivc m-elementary reactions occur a t the rate they do.” As written by someone more experienced than lie is in eleiiiriia consequence of this attitude, the author is content to tary teaching, but that he had now lost this Iiope. To this derott tire lines to the IiJ-drogeii-oxygen reaction, and four reviewer, a t least, i t appears very doubtful t h t oiie mort. to the oxidation of hydrocxrbons, while completely ignoring experienced i n elementary teaching could lin\-c tloiie better. the fascinntitig subject of esplosioii limits. There is also a Since the reviewer has also long sli,ired the co:ivictioii t h t niore serious consequcnce, in that the author gil-es the tlie elenieiitnry laws of phi-sical clieiiiistry -ire most siiiiply impressioii of IiurrJ-ing through tlie inechaliistic coni- understood i n terms of the Inech;uiisrn of iiiter.icti ~~f receive similar treatment. This attitude will encourage molecules of discrete energy, and tiitit thear a r e s i ~ i c c t ll)y errors in the initial researches of the advanced iitider- the Bohr relation. The ex:implci of tlie p.irticle i n h~\ graduate-hcsiniiiiig gr:idu:itc group t n which tllc h i o k is nnd ( i f tlie harmonic osciILitt>r ;ire t l i s c u ~ - r ~i ili tli.t.ii! iii directed. tlic scciliid cli.ipter the cniiccpt of tciii1lcr;itiisc’i- i i i 1 i w l i i i < i l This criticisin inxy bc illustr:itrtl I)!. tlie tlizcusiirw n i i d tlie st.itciucnt of tlit, I h ~ l t ~ ii iii !ii c l i - t r i h i i t i b : ~ l . i \ \ i ( p i ) . 147 -14i)l of the dccciinpi:’itiori ( i f 1.L’-(lic.iih)r~ietli:i~~r, made that t l i e re1,itive iiliiiihers oi ~ i i ~ ~ l c ~i : i wt \l\ c ~( ~ i i . i i i h i t l i nloiie aiid in1iil)ited by p r o p ~ - I ~ i eTlie . chain niech;1- t l l l i i .t:lti.< i. g i ~ e 1)) ~ i t’sli - ~ E , ‘ k l ’ . i:r
