BOOKREVIEWS
April 5 , 1033
rent research in this area. I n addition, it has a definite “how t o d o i t ” flavor; there are numerous examples t o 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 t h a t t h e chosen subject is in some \rays too narrowly limited. The analysis is formal a n d very little attempt is made t o give physical feeling for t h e problems. Furthermore, very little consideration is given t o the problem of proceeding from observed spectra to the calculations. Since in spectra t h e molecular vibrations always occur in vibration-rotation bands, it may be impossible t o assign these bands correctly or even t o 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 t o 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 t o 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 t o “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 t o be required reading for anyone begiiining to use molecu1,ir spectra. ~IETC.ILF RESEARCH LABOR.ITORS BROWSYSIVERSITY DOSALDI;. HORSIC 19, RHODEISI.ASD PROVIDESCE
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 t o 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 t h a t he had now lost this Iiope. To this d e r o t t tire lines t o the IiJ-drogeii-oxygen reaction, and four reviewer, a t least, i t appears very doubtful t h t oiie mort. t o 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 t h a t the author gil-es the tlie elenieiitnry laws of phi-sical clieiiiistry -ire most siiiiply impressioii of IiurrJ-ing through tlie inechaliistic coniunderstood 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 iitiderthe Bohr relation. T h e 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
