the Duclaux values of lower fatty acids, and the molecular weight by Rast's method. Chapter VI gives brief suggestions regarding the use of the literature, with the unexpected omission of Rosenthaler's "Der Nachweis organischer Verbindungen" from the list of books recommended to the student. Chapter VII (pp. 71-149), which occupies nearly half of the book and is headed "The Preparation of Derivatives," includes three subheadings: "The Properties of a Good Derivative," "The Selection of the Derivative," and "The Preparation of Derivatives." The second (pp. 72-138) considers the familiar classes of eompounds one by one, in each case mentioning the derivatives likely to be useful and the reactions involved in their formation, eivinn cross references to the orocedures in the followin< section. and appending the pertinent literature sources. There follows in mch case a tabulatton of compounds of the class, arranged in order of incrcssin~boiling pointsand or melung points with othcr physical constants included for certain types (e. g., specific gravity for hydraearbons, halides, ethers, esters; refractive index for aliphatic hydrocarbons, and some halides; optical rotations for mbohydrates). These tables include also the constants of the recommended derivatives. The tabulations of compounds in this section correspond to Kamm's Part C, "Classified Tables of Compounds." but are arranged wholly according to classes and not solubilities, this relsxation of emphasis on classification by solubility being in the writer's opinion an improvement. The tables are compact, and their value is greatly increased by the columns devoted to derivatives. The propriety of including these tabulations under the chapter and sectional headings mentioned seems questionable. The third section in this chapter presents twenty-four typical procedures (some with alternatives) for oreoaration of derivatives. The final chapters in the book deal respectively with "The Separation of Mixtures" and "Problems." The outline directions for separation of mixtures distinguish three types of mixtures: (1) those separable by differences in volatility, solubility, and class reactions, (2) those separable by fractional crystallization or distillation, and (3) those requiring a combination of the foregoing methods. There is pointed out and illustrated the fact that these same methods are ordinarily used for isolation of compounds from reaction mixtures. The problems in the final chapter are numerous and pedagogically excellent. They are designed t o test the student's ability to interpret various kinds and combinations of analytical evidence; some of the problems will require thought not only by students hut by their teachers as well. A careful eaamination of the hook lrft a very favorable general imprrasion. I n sornc matters of detail, in which differences of opinion are t o he expected, a few criticisms may be ventured. The procedure with respect to correcting thermometric readings for exposed stem is not clearly stated. On p. 49 sucR correction is specified for the melting point, but it is not mentioned on pp. 5 3 4 as reauired for the boiline ...ooiut.. and in the soecimen report on pp. 4>7 all melting- and boiling-point values are u n qualified. The line drawings of the melting-point apparatus (Figure 2, p. SO), and of the Siwoloboff boiling-point apparatus (Figure 6, p. 54), are not properly proportioned and are not consistent with the dimensions given in the accompanying text. The importance of having the unknown substance pure before identification is undertaken is not adequately emphasized by the directions on p. 43: "If the range of melting or boiling is very wide, indicating considerable impurity, the compound should be purified. . . ." There is no statement a s t o the accuracy with which qualitative and quantitative samples are t o be weighed. The method specified for weighing out esters (p. 64) would be troublesome and inaccurate with volatile esters. I n describing the Hinsherg separation (p. 26) it is not mentioned that dimethylaniline is sometimes quite unmanageable due t o formation of a purple dye; that primary amines almost invariably yield disdfonyl derivatives and therefore can be cleanly separated from secondary amines only after an interposed treatment with sodium ethylate; that sulfonamides are rapidly hydrolyzed by heatingin a sealed tube with hydrochloric acid, a procedure which is probably more convenient than the ten to thirty-six hours'
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refluxing recommended. Picrates are specified as derivatives for tertiary amines (pp. 125-6). but their usefulness for bases in general is not emphasized. The Sehotten-Baumann procedure is used for henzoylation of alcohols and amines on p. 25, hut is omitted on p. 146 as a method for making substituted benzamides as derivatives of amines. The procedure for preparation of uitroso-derivatives of tertiary aromatic amines (p. 147) appears to have such restricted analytical usefulness that its inclusion seems hardly justified. Three separate tests for nitrogen (obtained a s cyanide) are given on pp. 60-1, the familiar Pmssian blue test being third choice. The sulfacyanide test for nitrogen and sulfur present together succeeds so seldom that i t seems superfluous, especially in the present case, where there are given previously two tests for sulfur in addition to the three for n i t r a gen. The hook is well written and well arranged for laboratory use. The documentation is appropriately not extensive, hut is very satisfactory as regards recent papers on tests and derivatives, a number of 1935 references being noted. Misprints in the tent are few and incapable of harm; no effort was made to test the accuracy of numerical values in the tables. As a guide for laboratory work in qualitative orgauicanalysis, according to the system employed, the new book appears to be excellent, especially if its use is preceded or accompanied by suitable classroom work and reading, for which Part A of "Kamm" should be suitable. The writer will not venture here an opinion a s to the relative merits, practical and didactic, of the analytical scheme under discussion and that of Mulliken. Those who prefer Mulliken's classification based successively on elementary cornnosition. color. class reactions...ohvsical nrooerties. etc.. mav . not Get be recon&d.to the subordination of class reactions t o solubilities, by some of which homologous series are rather arbitrarily split. The attention of these may be called to the facts that the newer scheme of analysis has been thoroughly and successfully tried out, and without doubt more widely among undergraduate students than has "Mulliken," that it is much mare up to date than the latter, especially with respect to derivatives, and that it is obtainable in compact and inexpensive form, to which "Mullikeu" offers a valuable source of supplementary information. I t is the writer's belief that the cause of qualitative organic analysis would be much benefited .by (1) a complete revision of "Mulliken," with the analytical system and its accompanying explanations in a small volume, and the classified tables in separate volumes, and (2) hy a combination of the works of Kamm and Shriner and Fusoo. Teachers, advanced students, and investigators would then have a choice between two highly elaborated and equally modern systems of analysis, each with its characteristic advantages. E: C. WAGNER UNIVERSITY OB PBNNSYLY*NI* PIILIDBLPAI*, PA.
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PRINCIPLESAND APPLICATIONS O F ELECTROCHEMISTRY. VOL. 1. PRINcIPLEs. H. Jermain Creighton, Swarthmore College. Third edition. John Wiley & Sans, Inc., New York City, 1935. xviii 502 pp. 84 figs. 15 X 23 cm. $4.00.
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This text is so well known that a detailed account of its contents is untiecessary. The reviewer's opinion of its excellence is reflected in his requirement of its use as a text for over ten years. Certain features appear for the first time in the third edition. There is a good discussion of the work of Jones and Josephs on the theory and design of a conductance bridge and accessory Bpparatus. Brief discussions of the antimony and glass electrodes have been added. Likewise there is a page of comment on deuterium. The discussion of the Debye-Hiickel theory has been enlarged bv 50%. References are more numerous and uo t o date. The third kdition contains onlv 14 oaees more than'the s-na. Tn -~ .. ... .~. compensation several items have hrcn dropped out (without serious loss) so that the actual ncw material is more extensive than it appears on casual inspection. However, a page-by-page comparison with the second edition reveals that there has been little real change. The same prob-
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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 first 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 ~~~~~~~
