bustible gases. The text is divided into four main parts entitled: ( I ) Chemistry and Kinetics of the Reactions between Fuel Gases and Oxygen; (11) Propagation of Flames; (111) State of the Burnt Gas; and (IV) Problems in Technical CombustionProcesses. This is followed by three appendixes giving numerical data in the following fields: (A) Data for Thermochemical Calculations, (B) Limits of Inflammability, and (C) Flame Temperatures. The great virtue of this book, t o the reviewer's mind, is that the analyses of the problems involved are exact and specific. I n a complex and rapidly developins . .field of this kind. there is always room for alternative explanations. The reviewer feels that the authors have been wise in emuhasizine inves- the oublished . tigations (both theoretical and experimental) of themselves and their colleagues. A discussiou. for example, of the relative merits of the hydrogen-oxygen mechanisms proposed by Semenoff, by Hinshelwood and Williamson, and by the authors would have been tedious and necessarily incoudusive. As it is, one has a clean-cut exposition of the features of this complex reaction. I n addition, one is provided with references to alternative treatments. Such a procedure involves a certain amount of arbitrariness, and may leave the reader with a feeling that the whole story has not been told. The fact of the matter is that the whole story cannot be told a t the present time, as the authors emphasize in their preface. The requisite information is not yet available. The general reader should be warned that the development is essentially mathematical. There is, however, usually sufficient interpretation and description to carry him through. The book can be recommended to all those who require a modern treatment of gaseous combustion processes. ROBERTN. PEASE ~
ORLAAOMA A. AND M. COLLB~B STILLWATBX-,
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PBINCBTON UNIYBPSI~Y PXNCSTON,
errors is small. The elimination of considerable duplication, the addition of the periodic chart and the E.M.P. series would improve the test. On the whole, the test is a good one, neither too difficult nor too easy for high-school students, for the authors have sampled the representative and interesting parts of the high-school course with discrimination. 0.M. SMITH
NBWJBRSBY
GLENN-WELTONCHEMISTRYACHIEVEMENT TEST. Earl R. Glenn and Louis E. Welton. World Book Company. Yonkers-on-Hudson, New York, 1938. Test 1, Form A, $1.30 for twentyave copies; Test 2, Form A, $1.30 for twentyfive copies. This test, entirely objective, is written primarily for the purachievement of students in the fist-year high-school chemistry, t hc rcsults to be used as a basis for improving tlwir work. The test is in two sections, Test 1 to be uicd at the end of the f i s t semester and Test 2 a t the end of the second semester. Each of the two tests has five parts. Part I measures the students' ranee Part I1 can" of information of chemical facts. rams drawings representing chemical prinuples and quc.itions to drtmnine whether the students understand the pnnciplc.;. Wrt I I I measures associational vocabulary. Parr I\' contains drawings of laboratory apparatus and questions concerning their use and operation. The last, Part V, measures the students' knowledgeof and ability to solve equations and problems. Test 1 covers the parts of the subject usually taught in the first half year's work, and Test 2 the parts usually taught in the second half year. There are two forms. A and B, similar in content, organization and equivalent in difficulty having coefficients of 0.91 + 0.01. The questions are based upon a study of ten widely used textbooks. The reliability coefficients of Test 2is 0.93 + 0.01, and if both forms are used 0.96 + 0.01. A continuous period of seventy-one minutes is required to administer the test. This is a rather long period of sustained attention for high-school students; t o break the time would invalidate the reliability of the norms. The total number of points are 128 and 124, a sufficient number t o distribute the students satisfactorily. A manual of directions and norms is provided. The questions are interesting and challenging and are arranged with increasing difficulty, thus encouraging the weaker students. I n most cases the questions are clearly stated and should be easily understood. The ingenious use of many illustrations breaks the monotony of the usual test. I n some instances the object or the diagram are not familiar t o all students and in many cases the use of the illustration is of no aid, as, for example, a picture of a storage battery or a Pyrene fire extinguisher. The number of pose of analyzing the
SINN UND A ~ G A B EDER N GESCHICHTE DER CAE-
(The Sense and theProfitsof theHistory of Chemistry). Dr. ErickPietsck, Editor-it-Chief of Gmelin's "HANDBUCKDER ANORGANISCHEN CHEMIE." Verlag Chemie, Berlin, 1937. 15.5 X 23 em. 33 pp. RM. 0.90.
In this essay the author argues for the cultural value of the study of the history of chemistry, basing his conclusions on an examination of the interrelations between the history of chemistry and the cultural changes which have occurred in the Occident during the past century. The study, he says, is practical because it teaches us how to avoid the pitfalls into which investigators in the past have fallen, but i t is most valuable because of the understanding insight which it gives us into the cultural connections of the history of humanity TENNEY L. DAVIS MASSACBUSBITS INSTITUTE OF T&CRNOLOGY CAMBRIDDB, MAS~ACBUSBITL
STEROLSAND RELATEDCOMPOUNDS.E. Fricdmann, M.D., Ph.D. With a foreword by Professor Sir Frederick Gowland Hopkins, O.M., F.R.S. Chemical Publishing Company of New York, Inc., New York City. 1937. ia 100 pp. 153 figs. 16 X 23.5 cm. $3.00.
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This book, which is based on a series of lectures given a t the Sir William Durn Institute of Biochemistry a t Cambridge during the autumn term of 1936, is an attempt t o present t o the nonspecialist the more significant advances in the development of our knowledge of the steroids. The author "has dealt with the develooment of the subiect on historical lines. and oresented the more significant stages of that devclopmmt in logical sequence." The trearnlcnt of the strurtural intrrrdntionshipr and phgsiological properties of the various moups of steroids is adequate if not thorough. I n Lecture I the author wisely omits any discussion of the complex oxidative ring openings which led t o the old formulas for cholesterol and the bile acids, and instead shows how Wieland-Barbier degradations and side-chain oxidations led t o the correlation of the sterols and bile acids. The remainder of the lecture treats of scymuol; the stereochemistry of the bile acids; plant heart poisons; toad poisons; and the digitalis saponins. In Lecture I1 the progress made in the study of Vitamin D is described, including the biological experimentation leading t o the linking of ergosterol with pro-vitamin D, the irradiation products of ergosterol, and the recent work on other 7-dehydro-sterols. Lecture I11 describes f i s t the biological and chemical investigations which have led t o our uresent knowledee of the sex hormones, nnd wncluder with a survey of the work of Cook, Piescr. and othrri on carcinogsnic hy~lrurarbons. On the whole, this work is free of cross miriraternmti. A fcw errors should, however, be noted. The structure of scymnol (pages 2 1 4 ) is not definitely established, but i t is certain, contrary to the author's treatment, that scymnol contains no 3hydroxyl group, for the triketocholanic acid obtained from scymno1 is not identical with dehydrocholic acid. The author's use of hydrochloride for chlorokydrin (page 23) is indicative of a number of errors of another type. Contrary to the author's statement (page 54), ring closure from calciferol to pyrocalciferol generates only one assymmetric center. The only noteworthy omission is that of the cortical steroids. While little was known of these a t the time of delivery of the lectures, it does seem that some discussion of the chemistry could have been introduced in the later, published version. ~
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