JOURNAL OF CHEMICAL EDUCATION The disoussion of real systems is often more misleading than helpful. The author presumes t o generalize that a given formula may be trusted below a given concentration but not above it, his statements in justification are often contrary to experimental evidence, or even deny the existence of such evidence, and he seldom mentions more thorough theoretical treatments. The references, described as "oopious," are really very inadequate. T w o uut.itr.nding vnamplcs arc tllr disr!riiim.i of rhr w u n d virin1 weflirimr 01 it R:LS in C'llhl)t(.~I \ 2nd of thr i~llcrio!oirulrractwr, 11.wrv in ('hliimr lX. . I l ~ h ~ u gt ahb l ~ eof slindqrd cntlmlpies and entropies are mentioned, and a source to the former is cited, no indicat~ionis given that tables of standard chemical potentids (free energies) exist or that they are extremely useful. The important thermodynamic relations are, I believe, d l given, and the difficulty of fmding them is not increased enormously by the laok of an index. I t is interesting to be shown that other functions than those of Gibbs artre sometimes more conven-
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pressions for SIR, FIRT, etc.,have great advantages. The treatment of surfaces is less different from Gibbs than the discussion indicates. The important differenceis in the treatment of surface concentrations. Gibbs' method of fixing a surface so that the surface concentration of one component is zero is andogous to distinguishing one component as solvent in s. bulk phase. I t seems to me less arbitrary than the method used by Guggen-
in polycomponent systems. The specid chapters on "gravitational field," "electrostatic systems," and "electromagnetic systems" are very good. The "digression on statistioal thermodynamics" is beautifully done. The chapter on "electrochemical systems" seem to me the best in the book and a redly important contribution, but there might have been some mention of pH. GEORGE SCATCHARD MASS~CAUBETTB INBT~TIITE 01.T E O ~ O L O O Y C*~enroom,M*sa*cnossws
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G. F. J. Garlick, University of Birmingham, Birmingham, England. Oxford at the Clarendon Press, London. England, 1949. viii 254 pp. 127 figs. 15 tables. 14 X 23 cm. $5.50.
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GARLECK'S book is a. verv oomnetent account of the state of our
nescence, the mechanisms of luminescence in solid inorganic phosphors, and s, survey of the properties of the various classes of inorganic luminophors. These chapters will be of especial value to the beeinner seeking a well-balanced and clear exnosition of the subject; yet, a t thesame time, they provide the specialist in the field with a worth-while summary of dataon mast of the inorganic luminescent systems that have been investigated. A more thorough analysis of luminescence processes is found in succeeding chapters devoted to a detailed discussion of the properttes of aino sulfide luminophors; the electrical properties of phosphors, including photoconductivity and dielectric changes during luminesoence; and the response of phosphors to infrared radiation. A great deal of the most important recent work on phosphorsmuoh of it done in the author's laboratory-is presented snd discussed in these chanters. A separate chapter is devoted to cathodoluminescence, which is of such practical importance in television and radar. Deta on luminescence efficiency and decay time as a function of operating conditions are presented as well as discussions of the secondary emission ohrtracteristics of phosphors and of the penetration of electrons into solids. The author stresses the point that theoreti~
phors that some of the suggested approaches have already been &der way in many laboratories far some time, and that a. number of very significant contributions in the field of phosphors have been nublished too late for inclusion in the book. ~ h illustrations, k tables, and references to the original literature are numerous. The book is a. welcome and valuable addition to the literature of luminescence. JAMES H. SCHULMAN C n u s ~ ~Bnmcrr, r. NAVAL RBBBARCH LABORATORY WASR~NOTON. D. C.
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INFRARED DETERMINATION OF ORGANIC STRUCTURES
H. M. Randall, Emeritus Professor and Former Chairman, Department of Physics, University of Michigan, Ann Arbor, Michigan, Nelson Fuson, Professor of Chemistry, Johns Hopldns University, R. G. Fowler, Associate Professor of Physics, The University of Oklahoma, and I. R. Dongl, Research Phyldcist. 239 pp. 354 D. Van Nostrand Co., Inc., New York, 1949. v plates. 10 tables. 22 X 28.5 cm. $10.
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LUMINESCENT MATERIALS
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csl interpretation of cathodolurninescence has been hindered by the fact that the data have been taken on microcryshlline powders, and that such studies should be made on single-crystal material. The study of photoluminesrenee has, of course, been similarly handicapped and i t would be profitable to work with single crystals of phosphors in all investigations of their properties~ ..... A chlpter on the lurnirreu:err.e of orynuie rnafcrinls, both solids and wluriona, vonaiders the relation of lumincscbnce t~ rnt~lceular structure, and takes up polarization of fluorescence, quenching, photochemical sensitization, and the phosphorescence of adsorbed molecular systems. The limitations of our experimental and theoretical knowledge of luminescent systems are repeatedly and carefully painted out bv the author throurhout the text. The 6nal short chanter of the
CONTRARY t o the sdes literctture of the publishers of this book it is not a thoroughly complete work containing all the information needed for practice1 usefulness. I n fact, the authors in their preface state that "no claim is made to a complete treatment of the present status of infrared spectroscopy." Publishers of scientiti
