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I n format the book is first class, the binding and paper being of high quality. This book can be easily recommended to anyone in the field of physiological chemistry. As a laboratory text and reference book it is excellent. I t should be especially useful to anyone who is teaching laboratory work and t o all students doing graduate work in the field. CHARLES CARR. Mesot&Theory of Nuclear Forces. HY WOLFGANG PAULI.69 pp. S e w York City: Interscience Publishers, Inc., 1946. Price: $2.00. This small volume b y one of the most distinguished and active workers in the field of meson physics is based on lectures given a t the Massachusetts Institute of Technology in 1044, the notes of which are here published in but slightly amended form. Within the compass of sixty-nine pages Professor Pauli has given the meat of all aspects of the current theory, for both charged and uncharged mesons, and for the so-called weak and strong coupling forms of the theory. The treatment is really only a summary, rather than an ekposition. of the theory and is scarcely adapted for a first introduction; for the more sophisticated reader in quantum-methanical literature it will give an illuminating account of the present state of affairs in the theory of mesons. While the theory is unquestioiiably a brilliant attempt to extend the electromagnetic theory of photons, and in a certain sense has been vindicated by the discovery of mesons in cosmic rays, the present ambiguous state with respect to nuclear forces and the inherent mathematical difficulties make it difficult t o guess in what sense it will remain a8 a permanent part of our conception of nature. Professor Pauli's discussion gives a balanced account of both the successes and the failures of the theory to date. EDWARDI,. HILL.
FouTier Y'ramj(ir~iisand Slruclirre lg'actors. By DOROTHY WRINCH. 96 pp. Monograph S o . 2 of t.he American Society for X-Ray and Elect,ron Diffraction. February, 1946. Copips of the monograph can be obtained from the Treasurer of the Society, Dr. C. C. Murdoclc, Department of Physics, Cornel1 University, Ithaca, New York. Price: 54.00.
In just t,he same way that a crystal structure can be represented in terms of a reciprocal latt,ice every point of which is weighted with its corresponding structure factor, a molecule can be represented in terms of weighted reciprocal space (.4. Hettich: %. Icrist. 90, 483 (1935). 1'. P. Ewald: %. Krist. 90, 493 (1935). G. Knott: Proc. Phys. Soc. (London) 62, 229 (1940)). Such a representation is called the molecular structure factor, which is very closely related t o the Fourier transform of the molecule. This representation has proved particularly useful when the geometry of the molecules or groups comprising a crystal is known and the problem is to determine their relative orientation (A. Charlesby, G. Finch, and H. Wilman: Proc. Phys. 8oc. (London) 61, 4 i 9 (1939). J. Waser and C. S. Lu: J . Am. Chem. SOC.68,2035 (1944); the power of the Fourier transform is illustrated by its use here in reducing the original fifty-four unknown parameters in the biphenylene crystal t o four). In this short and excellent monograph, Dr. Wrinch has recorded the Fourier transforms of a large number of structural types, many of which occur frequently in a wide variety of crystals. These types include points of a lattice (Chapter 3) and, among others, tetrahedral, octahedral, and hesagonal sets of points (Chapter 4 ) . The discussion is extended (Chapter 5 ) to set.8 of many points on surfaces and within volumes based on a cubic lattice. The transforms of continuous distributions (Chapter 6) permit a discussion of composite distributions 6 ( D ) ,in which continuous distributions D are repeated by parallel displacement a t any of the sets of points 6 . Three classes of applications are mentioned: ( I ) When D represents a n atom, the composite distribution yields the transform of like or closely similar atoms a t the points of one of the sets 6. ( 8 ) When D represents the unit of pattern of a crystal and 6 the set of points of the lattice, the composite distribution is the crystal, and its transform is defined only a t reciprocal lattice points. (3) When 6 is a
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fragment of a lattice and D is the unit of pattern, the composite distribution is that of a small crystal. The transforms of small cubic crystals bounded by various forms are discussed in Chapter i . The possibility of the use of the Fourier transform is mentioned as an aid in the determinafion of the structures of megamolecular crystals in which the structures and even to some extent the compositions of the molecules are unknown. However, for the present we may expect the principal applications to continue to be in determinations of crystal structures containing molecules whose geometry is known a t least approximately. The best information obtained so far concerning the detailed principles upon which the structures of megamolecular crystals are based has come from the relatively few complete structural investigations of simple molecules related to the large molecules. Mathematically, Dr. Wrinch’s book is well preeented. The text is expressed in a compact style, which however is not always clear grammatically (e.g., parts of pages 19, 23, 63, 65, i o ) . T h e printing, binding, and paper are quite good. This excellent book can be recommended highly to anyone interested in the \r.iiys in which the Fourier transform can be used in structural analysis. WILLIAXS . LIIT.COMB. Fundamentals of Semi-micro Qualitative Analysis. By CARLJ. ENGELDER.54 x 8g in.; vi+ 385 pp. New York: ,John Wiley and Sons, Inc., 1947. Price: $3.50. This book differs markedly from the earlier conventional book on Semi-microQualitative A n a l y s i s by Engelder, Dunkelberger, and Schiller in that the theoretical material and laboratory directions are not separated. Each of the first five chapters comprising P a r t I, The Cations, begins with a discussion of some phase of the theory of qualitative analysis, which is followed by a brief discussion of the chemical properties of the ions, preliminary experiments that aid in carrying out the analysis, and a procedure for the analysis of the group. In each chapter, exercises are interposed a t suitable points. Advantage is taken of the simpler chemistry of the ions usually placed in Groups IV and V to pass rapidly into the theories fundamental to the proper understanding of qualitative analysis. Discussions of the ions of Groups 111, 11, and I then follow in t h a t order. Each of the three chapters comprising P a r t 11, The hnions, contains a discussion of the anions, procedure for the analysis of the ions, and some theory. As in Part I, exercises are placed to enable the student to determine whether he has grasped the subject or not -such as the p H of solutions, the theory of neutralization and hydrolysis, and the electrochemical theory of oxidation. I n Part 111, the systematic analysis of liquid and solid samples is discussed for both cations and anions. I n the Appendix is a discussion of colloids; the mathematics involved in qualitative analysis; suggestions to the instructor, including a weekly schedule; lists of apparatus and reagents; tables of the concentrations of reagents; logarithms; etc. The reviewer thinks that the mixing of theory and laboratory directions is a p t to confuse the student. Furthermore, if the anions are not studied, the theory i n this part will have to be worked into that given with the cations. Some of the statements in the theoretical part are questionable; for example, on page 37 the ionization of sodium chloride is said t o be “actually 85.2 per cent,” and on page 152 ff. “the per cent of ionization of 0.1-M sodium hydroxide, hydrochloric, and nitric acids is 91-92%, while that of uni-univalent salts is 8&85%, uni-bivalent salts is 65-75%, and that of bi-bivalent salts is 35-45%.” The use of single and double arrows is confusing. On page 62, a single arrow is used in the equation for the precipitation of a difficultly soluble substance, and on page 64 double arrows are used. Similarly, single arrows are found i n equations used t o write expressions for the appropriate equilibrium constants on pages 68, 135, and 189, and double arrows on pages 184 and 261. The expression for calculating the concentration of a n ion, “Molarity x per cent of ionization” on page 157 is only partly correct. The procedures in general are conventional and are undoubtedly satisfactory. G. B. HEISIG.
