BOOK REVIEWS sorption from solution as a tool in measurement of surface area. By contrast with the others, all but Chapter 14 give the impression of hasty writing. The thermodynamic treatment is soond, although this reviewer prefers Everett's definition of surface excess to the more uwnl Gihhs'. Also Dr. Kipling tends (don't we all?) to incorporate a discussion of models and statistical treatment into the chapter labeled "Thermodynamic?!' G. N. Lewis seems right in asserting that thermodynamics is a useful formalism a d nuthing more. It is a pleasure to end this review with a commendation of the exeell~nreof the three indenw,systems, authors, subjectseven though i t seems necessary to mourn the absenre of a short succinct summary for each chapter. The final words are "Buy it today" (for research and reference). Mnwonr~J. \-OLD Uniuercilg qf Southern Calijornia Lo6 Angeles
KekulL und seine Benrolformel: Vier Vorlrige
R. Wizinger-Aust, Basel, J. B . Gillis, Ghent, B. Helferich, Bonn, and C . Wursler, Ludwigshafen/Rhein. Berlag Chemie, GMBA, Weinhe~m/Bergstrasse, West Germany, 1966. 93 pp. Plates. 16 X 24 cm. 10 marks (about laZ.50).
The centenmy of the annom~cementof the Kekul6 hexagonal formulation of benzene was suitably observed a t Bonn in September, 1965, by the C:esellschaft Deutscher Chemiker a t its nst.ionsl meeting. The four invited lerturers were authorities on the life of KekulB and the consequences of his theory, conceived while he was professor a t Ghent and more fully developed a t Bonn, where he spent the last period of his career. The respective leotorw bear the titles: August Kekul6, Leben und Werk; Leben und Wirkeu von Kekul6 in Gent; Zur Geschichte der Chemie in Bonn: Die heutige Bedeutung der Benzolchemie. Their text? have been gathered into the present volume together with a prefatory word by Richard Kuhn (Heidelberg). Numerons wellchosen and beautifully reproduced photographs, drawings, etc., add much to the interest and attractiveness of this fine volume. The lectures themselves are full of meaty information and are a joy t o read. Teachers, students, and lovers af the history of our scienceshould he grateful for this opportunity to acquire a t a modest price this fine souvenir of a great milestone in the advanceof organic chemistry.
RALPHE. OESPER University of Cincinnati Cincinnati, Ohio
