colloid science, intended for undergraduate students and far conscientious instructors who feel an obligation to provide such students with an opportunity for challenging independent study. The book consists of 112 pages of textual matter and a good index. The first chapter deals with the limits of dimensions in the colloidal state, the importance of interfaces, and enough history to provide an essential perspeotive. The classification of colloidal systems is also considered. The second chapter is concerned with lyophobic sols, which, following K. J. Mysels, are classified as diuhLmnl if they persist substantially unchanged for long periods and as wducovs if they have a short lifetime. Methods of preparing sols are described, as well as the theory of sol formation. Electrokinetic phenomena are discussed in relation to zeta potential. The third chapter deals with lyophilic colloids, i.e., substances which form true solutions although composed of molecules large enough to be in colloidal range, such as the proteins and the nucleic acids. The discussion of the osmotic pressure of such solutions leads to consideration of tbe Donnan effect and the need for adding a swamping electrolyte in determining the molecular weights of polyelectrolytes from osmotic measurements. Other topics d i e cussed include swellimg and gelation, light scattering, ultracentrifugation, and the viscosity of lyophilic systems. The fourth chapter considers association colloids, i.e., substances whose molecules aggregate spontaneously in a given solvent to form thermodynamically stable particles of colloidal dimensions. These include most of the surface-active substances used as detergents or as wetting, suspending, or emulsifying agents. The authors discuss the structure of spherical mieelles, the critical micelle concentration, electrical eonductivity of ionizable association colloids (says Kerol Mysels: "I measure the conductivity of micelles in my cells"), solubilisation (the phenomenon so extensively studied by McBain), coacervation and the mesomorphic state. In the 6fth chapter the authors give attention to interfacial phenomena, surface tension being a special case of the interfacial tension resident in any mobile interface. Applications considered here include the spreading of liquids, the wetting of solids, ore flotation, dyeing, and detergency. The Gibbs relation between adsorption and interfacial tension is considered, as well as monolayers on liquid surfaces (the work of Agnes Pockels, Irving Langmuir, and their successors). The authors devote the h a 1 chapter to a. description of a few colloids that have achieved theoretical, industrial, or hitorical importance. Bentonite is considered because of its thixotropic character which finds application in drilling muds; included are the alkyl ammonium bentonites (organophilic clays), used in specialty lubricating greases and in thixotropic paints. Sulfur sols are considered because of their prominence as "typical" lyophobic sols in the early history of colloid chemistry and because LaMer and his colleagues have recently applied nucleation theory to the production of monodisperse sulfur sols. Finally, some of the remarkable properties
The fourth chapter deals with modes of bonding in inorganic complexes, Five pages are devoted to the Lewis-SidgwrckLAWRENCE P . EBLIN Pauling valence bond theory, including Ohio Unive~sitY hybridization. Eight pages are utilized Athens for the discussion of crystal field theory. Two pages are devoted to =-bonding and one paragraph to "sandwich" compounds. In the 6fth chapter, Properties and Chamcteristic Reactions, eight pages are devoted to stereochemistry. Separation Inorganic Complex Compounds of isomers, the differencesbetween geometrical isomers, cis trans isomeriaation, and R. Kmt M w n n , University of Misracemiat~tionare discussed. Other topics: souri, Columbia. Selected Topics in stabilization oi unusual oxidation states; Modern Chemistry. Reinhold Pubthe acid-base properties of complex ions; lishing C o p , New York, 1964. viii ligand exchange, including the use of 120 pp. Figs. m d tables. 12.5 X isotopically labeled ligands for the study 18.5 em. Paperbound. $1.95. of substitution mechanisms; and the reactions of coordinated ligands. Like the other volumes in this series, The final chapter gives brief mention t,o Professor Murmann's little book is written some of the more common applications of more in the style of a monograph than in coordination chemistry and closes with a the manner of a textbook. In a book inthree-page discussion of the role of metal tended to serve as a supplement to a complexes in biochemistry. The use of standard textbaok, this style seems structural formulas here again points up appropriate. There is, of course, the the need for making sure that the students implication that such supplementary have some knowledge of organic chemistry re%ding is not intended for students who cannot follow their textbooks. before they attempt to explore inorganic In the first chapter the historical decomplexes in depth. velopment of the subject is followed by a The effectiveness of this little book as a supplement to a freshman textbook will discussion of the difficulty of defining codenend on the timing of its use and the ordination compounds. The existence of eakful planning of the course. complexes in situations often regarded as "simple" is illustrated by the reaction of LAWRENCE P . EBLIN cesium(1V) with tin(II), where it is well Ohio Uniwraify known that these hare ions do not actually Athens exist in aqueous solution. The species present in a solution containing Ce(1V) as the chloride inolude [Ce(H20),14+, [Ce(HsO).Cl] a+, [Ce(H~O),CL]?+, and [Ce (H20).(OH)]B+, as wellas dimers and polyInorganic Ion Exchangers mers having OH and CL bridges. The existence of metal complexes in situations C. B. Anphlelt, Atomic Energy Research which nobody ever imagined to he simple Establiihment, Harwell, Great Britain. is illustrated by the presenceof coordinated American Elsevier Publishing Co., Inc., iron in hemin, magnesium in chlorophyll, New Yark, 1964. Topics in Inorganic and cobs.lt in vitamin Ba. and General Chemistry, Monograph The discussion of methods of discerning 141 pp. Figs. and tables. No. 2. x complex formulation should he very bene14 X 21.5 cm. $6.50. ficial to the student who is intorested in evidence: for example the faihm of Ion exchange was investigated on inFe(OH)* to precipitate upon addition of organic materials in soils over a century OH- to a solution of Fe(I1) in the presago. The first synthetic exchangers were ence of EDTA; the ability of an anionic inorganic; but a greater interest in organic exchange resin to take up [ZnCIJ- alion-exchange resins developed and little though unable to take up Znzf; evidence attention was given to inorganic materials based on molar conductivity; and so an. until recent years. Prompted by the The first chapter includes an explnnar need for ion exchangers which are more tion of haw formulas for com~lexesare stable at high temperatures and in the presence of ionizing radiation new materials have been developed. Inorganic ion exhangera are classified of isomerism found among these cominto two types: exchangers with wellpounds. There is nothing in this chapter defined crystal structures (the two dimenthat is heyond a good freshman student. sional layer-lattice structures, such as the For the most part, however, the subday minerals, and three dimensional sequent chapters require more backcage structures exemplified by the zedites) ground (or greater effort). The second and poorly crystalline materials (hydrous chapter, entitled Thermodynamic Star oxides of polyvalent metah and acid bility of Complex Compounds, employs salts of palyvalent metals and polybasic thermodynamic terminology and also reacids). A group of miscellaneous ellquires that the student know enough orchangers are mentioned including uranium ganic chemistry to distinguish between micas and merearbide salts. Chapter 2 primary, secondary and tertiary amines, covers the clay minerals systematicdy by and to recognize such terms as acetylacetype, including montmorillonite, attatonate. The third chapter, Reaction pulgite, mica, vermiculite and kaolinite. Speeds of Complex Species, cannot be The use of these minerals for treatment of properly appreciated by 8, student who radioactive waste solutions is disoussed. does not know how to perform integrat,ion. Chapter 3 discusses the zeolites including a
of the commercially important silica gel are described.
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Volume
42, Number 8, August 1965
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459
