lems reappear. I n particular it is regrettable that no satisfactory conventions are given for establishing the sign of cell potentials, liquid junction potentials, and the free energies of cell reactions. The importance of such conventions, as the reviewer has found by hard experience, especially when dealing with liquid junction potentials, is very great. The definition of "normal" or "electrolytic" potential continues to be unsatisfactory. I t is not made clear that by "molal." activity mold or unit activity is implied. At least it should be implied t o be consistent with the table of electrolytic potentials, many of which are elsewhere called "standard" potentials, i. e.. based on unit activity of the ion. Since electromotive force equations are based on the activity concept, such quantities should be used whenever available. I n any case the distinction between ion concentration and ion activity should be sharply drawn in connection with any discussion of E.m.a. A reference to "Indicators" hy Kolthoff and Furman could he added profitably t o the chapter on that subject. On the whole the third edition may be considered somewhat improved over previous editions. I t can certainly be highly recommended t o all teachers of the subject. MALCOLM M. HARING UNIVBRSITY OF MAPYLAND COLLBOB PA-, MD.
G. Demixg, Professor of Chemistry, University of Nebraska. Fourth edition. John Wiley 769 pp. 170 & Sons, Inc., New York City, 1935. xiii figs. 13.5 X 22 cm. 83.50.
GENERALC H E M I S ~ YHorace .
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This well-known and successful textbook was first published in 1923. and the third edition appeared in 1930. During the last five years there have been notable discoveries and developments in chemistry, so teachers will welcome the new edition of General Chemistrv in which many of the modem ideas of cheniists are introduced and applied. According the~title ~ - to ~ ~ w . e~..e .. the book is "an elementam survev. . emphasizing industrid applications of fundamental prineiplrs." It contains 8.1 pages more than the third edrtion, and the brder and character of the subjwt matrcr differ in a number of respects. Like the earlier editions, the text is divided into four parts: Part I. General Principles (223 pp.). Part 11. The Nonmetals (312 pp.). Part 111. Organic Chemistry (68 pp.). Part IV. The Metals (146 pp.). These subdivisions are not strictly adhered to, however. Thus, oxygen and hydrogen are treated in Part I, and certain theories and principles are presentedin Parts II-IV, where they natufally belong. In the Preface, the author says: "Teachers everywhere have been very emphatic that there is danger d overburdening the beginner with theory before he has acquired a proper background of facts.. Moreover, some of the more difficult or advanced topics have been deferred to the close of the hook. By thus departing from a completely logical arrangement we feel that the book will give better service in the haids of students who have had no previous training in chemistry, and who are perhaps deficient in mathematics and physics as well." While derivation of chemical formulas and the determination of molecular and atomic weights were presented in Part I of the previous editions, they are deferred to Chap. XXXVII (p. 569) of the fourth edition. This is a radical departure from the usual practice. The b w k has been thoroughly modernized and contains an increased amount of physical chemistry and physics. This will be welcomed no doubt by teachers who have been calling for the "modernization of the general course." The turn, isotope, is first used on page 32 in connection with Dalton's atomic theory; surface tension is discussed on page 113; and "heavy water" is mentioned on page 126. Prominence is given t o the electron and ions in the fmt part of the book. Chapter XI1 (10 pp.) is devoted t o the crystalline state. The author has "the conviction that the fundamental differences between ionic and covalent compounds tend to be obscnred by
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defining acids, bases, and salts from the molecular paint of view, then going over very much the same ground again from theionic point of view." Gaseous hydrogen chloride, HCI, and pure hydrogen nitrate, HNOI, covalent compounds, are considered as acids, since each loses a proton, H+, when dissolved in water: HCI
+ HzO -+ C1- + &0+.
LA
Oxonium-ion
H+ The formula for the hydrated proton, HsO+,is used in place of the symbol Hf. An acid is defined as "an ionic compound which on being dissolved in a givcn solvent will +Id the same cation as th; solvent itself, but a different anion" (D. 196). The interaction of a metal with an acid is expressed as f&ows:' Zn
+ 2Ha0'
+Zn++ + 2H,O
+
+ HI t ;
and neutralization as H 8 0 + OH- +2H20. The equation for the formation of H%Sis written thus (p. 287): H8O+
+ s-- --+ Has t
f H20.
One reads on page 331: "The formula of sodium hydroxide, NaOH, is a mere conventional formula, representing two independent substances, sodium-ion and hydroxyl-ion." Covalence, covalent bonds in ions, and codrdination are presented in considerable detail, some attention being paid t o the sizes of atoms. Chap. XXVI (18 pp.) is devoted to reaction rate, and it includes such topics as activation energy; details of activation and deactivation; unimalecular, himolecular, and tenmolecular reactions; successive reactions and reaction order. "Chain reactions" are also defined and illustrated. Sixteen pages are given to photochemistry, such suhjects as quanta. Einstein's photochemical law, chemiluminescence, and photography being discussed. Less than two pages are given to antimony and bismuth, and no bismuth compounds are mentioned (p. 451). "Activity product" is substituted for "solubility product" (p. 515). and proton equilibria are disoussed (p. 519). I n aqueous acid solutions, the total acidity'inay be made up of two parts: (1) Ionic acidity, due to oxonium-ion. HaO+. (2) MoZecz(1ar acidity, due to non-ionized acid molecules. The hydrogen electrode, indicators, and buffer salts are treated in some detail. Three or four pages are devoted to absorption spectraand the Raman effect. Chap. XXXVIII takes up synthetir products, both industrial and medicinal. Structural formulas ire given for such complicated substances as pinene, camphor, cocaine, pracsine, aqd hutyn. Synthetic rubber and hormones are discussed briefly. The chapter on electrochemistry is fairly detailed, considerahle attention being paid to oxidation-reduction potentials. Since 626 pages are devoted to general principles, uon-metals. etc., the space left for the metals is limited. Certain topics are treated very briefly. Thus, 7 lines are devoted t o the production of magnesium. 2 pages to chromium and manganese and their compounds, and about 6 pages t o tin and lead and their compounds. The last chapter is concerned with nuclear reactions and radioactivity. The reviewer feels that it is more logical to deal with these topics in connection with the structure of the atom. Like the former editions, the book contains many excellent questions and problems designed t o test the student's ability t o think. It contains also a very large number of references t o current literature. It i< thc opinion of the reviewer that some portions of the text are too di&cult and dctailed far hcginners. It is bcttcr adapted to studcnts who hare had a good course in high-school chemistry, and particularly to those who devote only one college year to the study of the subject. For students specializing in chemistry, some teachers would probably prefer t o pay more attention t o what may be called "classical chemistry," Leaving some ~~~~~~~
of the modern material for later courses. Fortunately, not all teachers think alike so we have variety instead of uniformity. General Chemistry is a scholarly production, carefully and clearly written, and is well illustrated. It should make a strong appeal to teachers who desire a thoroughly modem textbwk and who wish to stress certain aspects of the newer chemistry. The publishers have done their part well. The book is printed on excellent paper and is attractively bound. WILLIAM FOSTER PR~NEBTON U-ERSITY New Jeassv
ParNCSTON,
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I m o ~ u c r ~TOo ~ INORGANIC CHEMISTRY.G. H. Cartledge, Head of the Department of Chemistry, The University of Buffalo. Ginn & Co. Boston, 1935. vii f 609 pp. 52 figs. 14 X 20.5 cm. $3.00. LABORATORY EXERCISESIN INORGANIC C H E M I S ~ YG. . H. Cartledge and H. M . Woodburn, The University of Buffalo. Ginn & Co., Boston. 1935. v 149 pp. 23 figs. 14 X 20.5 cm. $1.00.
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energy change, quantum number, reaction velodty constant, and Planck'sconstant. Adds, bases, and salts are developed hy t h e h h e n i u s theory, with no mention of other viewpoints. The Laboratory Exercises i n Inorganic Chemistry is a worthy companion of the textbook, whose unique order makes a special laboratory manual necessary. The authors have assembled a list of 25 experiments each leading "to a conclusion of more than test-tube proportions." There are, for example, no experiments whose end is the preparation of hydrogen, chlorine, or hydrogen chloride. hut each of these is prepared or used "in a natural way as a necessary step toward the attainment of a larger goal." The appendix contains lists of materials as well as some of the tables which appear in the textbwk. The teacher who has grown weary of the familiar textbook plan of organization with its tedious recital of the facts of descriptive chemistry and is longing for a new approach to the science with an attractive and modern treatment will find these hooks fresh, new, and vigorous. The teacher who expects a textbook to furnish detailed information about the materials of chemistry and their functions in modern life may find too much theory and too little attention to fact and application. T o all the books will appeal a s excellent products of a successful course of study, and the authors are to be congratulated upon presenting a unique plan, a skilfully designed course, and well written, splendidly executed books which are real contributions to modem B S. HOPKINS chemical education. U N l Y B R S I n OP ILLIN018
These books are products of the careful study of methods of teaching chemistry which has been made a t The University of BufIalo. In the preface to the textbook the author questions the effectivenessof the conventional inductive approach "according to which the individual student has t o a considerable degree retraced the laborious pathway by which the science was deURBAN*, ILL. veloped historically.. The point of view adopted in this course is that we now know a great deal about atoms, and that we may apply this knowledge t o deduce and correlate a large number SCIENCECRAFTMINERALOGY MANUAL.Francis Burt Roseuenr. of facts." A.M.. Cornell University. Published for and copyrighted by I n accordance with this plan the first two chapters deal with the Porter Chemical Co., Hagerstown, Md., 1935. 143 pp. 12.5 customary introductory matter, after which there are chapters X 25 cm. Illustrated. Paper covers. $1.00. devoted to Atoms and Elements; Atomic S t I U c t ~ and e Chemical Change; and Mass Relations in Chemical Change. T o illustrate This manual of mineralogy is evidently intended t o accompany the principles outlined in the first five chapters, the author selects the "sets" of specimens of minerals which the Porter Chemical the short period sodium t o chlorine for detailed study. These Co. has prepared for sale to youthful and other amateur students elements are chosen because they are typical members of their of minerals. I t will be recalled that this is the company which respective families as well as for their practical importance. has done so much to interest youngsters in chemistry through the This order has the advantage of bringing typical metals into the Themcraft" sets. The first part of the manual gives a conearly part of the course and it serves to impress upon the mind densed hut well-planned exposition of the fundamentals of the of the beginners the idea that "there are physical reasons be- subject under consideration. This incluldes some elementary neath the observed facts of chemistry." instruction in the use of apparatus, a brief account of the eleOther chapters are devoted t o Solutions; Chemical Equi- ments of geology, of chemistry, and of crystallography as applied librium; Periodic System; and Nitrogen Family. Such subjects as to mineralogy, and chapters on physical and chemical properties Electrochemistry, Photochemistry, Colloidal Solutions, Carbon in general and of blowpipe and chemical tests as applied to the Compounds and Radioactivity are not developed in separate identification of minerals. Most of the remainder of the manual chapters but are "woven into the text where i t j s believed they deals with descriptive mineralogy, considering,many common may he most e5ectively taught." Hydrogen, oxygen, and the and some less common minerals in systematic oriler, beginning halogens are placed late, while the remainder of the petals are with the elements and going on with the sulfides, oxides, halides, grouped together in four chapters. In all there are 24 chapters, carbonates, etc. Chapter VII gives a good condensed account the last being devoted to Sulfuric Acid and the Alkali Industries of gems and gem minerals. A chapter on "collecting" follows The highly condensed treatment of certain of these topics might and the final chapter contains tables useful in the identification raise in some minds a question as t o why the word "Inorganic" of minerals and instructions on their use. was included in the title. Scattered throughout the hook are some 128 experiments which The chapters are concluded with stimulating exercises, many are designed to illustrate tests for individual minerals. Most of of which are distinct departures from the conventional style. these experiments are simple and the instructions are clear and Some of the problems may be pretty difficult for beginners. excellent. The whole aspect of the manual is more like that of a Answers to a fiw of the problems are given in thq appendix. serious educational work of elementary character than like a The book is not profusely illustrated, but the illustrations commercial production. In fact, teachers of courses in minerhave been carefully selected far their usefulness. The line draw- alogy might profit by a study of the method of this manual and ings show outstanding merit. The appendix is brief but proh- copies of it would be of value in the departmental libraries of ably contains most of the information which is needed. The schools and colleges. FRANKB. WADE index is complete and the mechanical features of the book have THB SBOETRIDDB H I OScaoor. ~ been carefully considered. INDI*N*PO'.B. 1ND. The approach through atomic structure permits the author t o o5er his~discussionsin terms of modern theories which are used FILMS. 1000 AND ONE. THE BLUE BOOKOF NON-THEATRICAL generously. Most of the fundamental conceptions of presentThe Educational Screen, 64 East LakeSt., Chicago. IU. Elevday physics and physical chemistry are employed in the exenth edition, 193536. 144 pp. 10.5 X 18 cm. W.75 (to planations of chemical phenomena. There is free use of such Educationa2Screensuhs~ihers,$0.25). terms as activity cae5cient. coBrdination number, dipole, free
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