concepts. Second will come a phase of small p u p s t u d y during whichstudents in groups of three or four solve speoifio problems which have arisen as part of the course. This phase includes class work, library work, and laboratory work with appropriate emphasis on the laboratory work where students a t first-hand discover, define, investigate, invent hypotheses, and devise experiments to test these hypothesen. At the conclusion of this phase, the students are expected to enter upon the third phase, individual study, wherein they identify, define and pursue problems which have arisen in previous work. Following the work included in the fundamental core, a series of experiments involving qualitative analysis are recommended as 8 means of requiring individual planning and effort. At the conclusion of the work in qualitative analysis, students are expected to move on to an investigation of other problcms of their choice. I t is apparent to these reviewers that the suggestions made by the author can, and when effectively carried out will, lead to a very stimulating and successful high school course in chemistry. But it is equally apparent that this procedure can be carried out only by a teacher of considerable competenoe and considerable experience. Part 2 consists of selections from fundamental content and is made u p primarily of demonstrat,ions and experiments which have been submitted by a variety of authors. Unfortunately, these have not been carefully edited and contain many booby traps far the unwary, including such statements as, on page 123, "sodium chloride dissociates i n water to farm sodium ions and chloride ions. These two ions with the ions of water can form sodium hydroxide and hydrochloric acid." While the conclusions are essentially correct, the implied mechanism is not. Part 3 is devoted to safe and effective use of the laboratory. Again many u s e ful techniques and devices are included which have been submitted by contributors. These reviewers must emphasiee their reservattions concerning the use of the laboratory without adequate responsible supervision. Part 4, entitled areas of special study, includes many useful suggeetions for work with colloids and oreanic chemistry which might be used by &dents who work more ranidlv or which on oecmion mav
by contributors. A number of more spectacular experiments have been included in chapter 14 under the heading of Special Demonstrations and Science Show Materials. Part 5 is concerned with student projects, both studentnirected and teacherdirected, and includes a number of suggestions submitted by contributors. Part 6, which concludes this volume, contains suggestions for those teachers who might find themselves in a situation where they have no chemistry laborrttorg. The preface opens with the statement that "This book is intended as an aid to the ehcmi~tryteacher." This is certainly true for a teacher reasonably well versed
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Iournol of Chemical Education
in the elements of chemistry. These reviewers, however, cannot agree that it should serve "the science teacher who has not been trained in chemistry hut must teach this course because there is no one else to do it." A high degree of skill and a firm grasp of the subject are required for success with an open ended program. Many of the procedures described in the book would be extremely hazardous far the uninitiated.
WAYNE TAYLOR and F. B. D n r r o ~ Michigan Stale Uniuersily East Lansing
Nouveau Trail6 de Chimie Minirale. Volume 16
Paul Pascal, Membre de l'Institut, Professeur Honoraire a la Sorbonne. Masson E t Cie, Editeur Libraires de L2Academie de Medecine, Paris, 1960. 1195 pp. Figs, and tables. xxxix 17.5 X 26 cm. Broche (two volumes) 170NF. Cartonne toile (one volume) 185NF.
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Elements of Group VII, as subdivided into the halogens (F, CI, Br, I, and At) and the transitionmetals (Mn, Tc, and Re), are disoussod in this volume of Pascal's new treatise. Pascal himself has written introductions to tbe two subgroups, in addition to all the material on bromine and iodine. L. Domange, A. Chretien, and M. Haissinsky are the respective authors of the sections on fluorine, chlorine, and astatine. The material on mtlnganese was written by M. Geloso and J. Faucherre, and S. Trihalat is author of the sections on technetium m d rhenium. Part of the bibliography on chlorine was assembled by Joseph Heubel. Bibliographical references total 9576. With the exception of the astatine bibliography, literature searches do not seem to have been conducted beyond 1958, and oneof Pascal's own searches did not go beyond January 1, 1956. The volume examined by the reviewer did not appear to measure up to standards of binding observed in earlier volumes. The index is not as thorough as might be expected for a volume which includes the halogens, but while criticisms may be made, the work does measure up to the generally good standards of the treatise as a whole. The supplementary volume of Mellor on the halogens published in 19.56, in addition t o being in English, ha8 other advantages over Pascal's treatise, but the time lag in publishing supplements far Gmelin, as well as its plan of coverage through 1949 only, gives obvious advantageges to the Pascal volume. Despite same shortcomings, this volume with others of the set published previously will make the Pascal treatise not only s. desirable but almost a necessary reference tool in inorganic chemistry. ROGERV. K R W University of Flmida Cainesville
Valency: Classical and Modem
a. Palmer, Fellow of St. John's College, Cambridge University. 2nd ed. Cambridge University Press, New 244 pp. 61 figs. York, 1959. ix and 43 table^. 15 X 22 cm. $5.50. W.
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This book emphasizes the fact that valency is a chemical concept that was well developed before the development of the modem physical theories that &re now considered to be basic to its understanding. The first three chapters briefly survey the historical background, the methods of determining structure, and the distribution of valencies in the periodic table. The last three chapters are an introduction to the modern views of valency and some special topics such as hydrogen bonding and electron deficient compounds. The fourth chapter, a very elementary discussion restricted t o the elements before the &st transition group, is said to provide, together with the first three chapters, "a compact but elementary account of classical and modern conceptions of valency, suitable for the generalreader!' The style is good, the abundant factual material seems well documented, and the numerous tables and figures are well chosen and clearly presented. In particular there is always a clear distinction made in the diagrams between lines connecting atoms or ions and l i n e outLining geometrical figures. Thrre are some things, however, that detract from the over-all excellence. One, a result of the historical approach, is the use in the first part of the book of "bond diagrams" in which each bond line represents one valence unit, not a shared pair of electrons. This leads to The formulations such as N=N=O. author has also added the term "coionic" t o the long list of synonyms for the coordinate covalent bond. On page 95 the name "periodic acid" is called a misnomer because the compound does not contain a peroxy group. On page 58 the term carbide is said to he reiierved for salts containing the CI- ion, thus pushing compounds such as F e G and Be2C into a nameless limbo and drawing an unwarranted distinction between covalent and ionic acetylides. A discussion of the meanings of the terms valence, valency, and oxidation number would have been a welcome addition. Bemuse of the very elementary level of treatment, this is not a suitable book for a text even in undergraduate courses. However i t would make a very good outside reading assignment. A good high school student with a year of chemistry could read mnch of i t with profit. Even graduate students would do well t o familiari~ethemselves with the classical background of valence theory. Not least of all, teachers will find mnch intereating factual material and wme new ways of presenting rather complicated material in an elementary fashion.
JR. R. F. TRI~BLE, Southern Illinois University Carbondale (Continued on page A660)
