he may be pardoned for raising certain points for discussion. On page 25, in discussing the validity of the solubility-product principle, the statement is made that the "concentration of the nonionized molecules is a constant." Now i t has heen proved beyond question that this is not true. Moreover i t is not necessary t o make such an assumption. The important thing is the fact that the "product of the concentrations of the ions in a saturated solution is very nearly a constant," whether the non-ionized part is a constant or not, and in the very dilute solutions in contact with quantitative precipitates the non-ionized part is a negligible factor. Some teachers question the usefulness of *'explanatory notes;' arguing that students will not read them. They think that all such statements should be so woven into the "procedure" that the student is obliged t o get them. Personally, the reviewer thinks that a student who has to be tricked into learning anything is not worth saving. It is easy enough to find out whether he does know such things by use of classroom quizzes, and it would not be a bad idea t o make these quizzes precede the laboratory work, if possible. A good student will leard everything he can; all he needs is the opportunity, and this is adequately presented in the explanatory notes. There is a question, on the other hand, whether the material included in these notes might not better he woven into the introductory "Method." and so made t o introduce the "Procedure." This would be the loeical order. and the "ewd student" would profit by it. The reviewer has not done this in his own bwk, but he is thinking of making the change. One other point: it is getting t o be rather common now to let volumetric analysis precede the gravimetric, the argument being that the volumetric is easier. To the reviewer i t seems advisable that a t least acidimetry and alkalimetry, with a proper study of indicators, should come fist, largely because of the great importance of such matters in precipitation reactions. On the other hand, volumetric oxidation and reduction should be preceded by a careful study of potential relations, and so might well be deferred t o near the end of the coune. Volumetric precipitation reactions are probably best studied after other precipitation reactions have heen taken up. Here again the reviewer ackmwledges his own inconsistency but pleads the right t o change his mind. Oesau~ COLLBCB W. H. CHAPIN OBBRLIII.Orno
sulfones, sulfonyl compounds, isonitriles, and nitro compounds are subjects which seem to the author to be of great importance. They have, therefore, been included. On the other hand, the electronic formulas for aromatic compounds have been omitted as there is a t present no agreement on this subject and the proposed formulas have little t o recommend them to an elementary student. I n short, the electronic theory of valence in the present stage of its development has little advantage over the usual structural theory in a consideration of hydrocarbons and their oxveen derivatives. I n dealinn with manv nitroeen and sulfur " cotnpounds. however, tlw electronic theory can he of great service and i n tlmc caws a brief cnniidrration of it seems uannnted in even a first year's course." The last two chapters deal with "Plant and Animal Pigments, Sterols, Vitamins" and "Advanced Topics in Stereochemistry." The author states in his Preface that he "would not maintain that the subjects considered in these last two chapters are more imoortant than manv others which mieht have taken their dace. Both chapters ir~cludrconGderahle n e e material which has been discovered in the h $ t few )cars. I t is hrliev~dthat the nmbitious student is often more interested in pursuing some current development of the subject than in studying some equally important development of the past." The book is supplied with an excellent index. It is interesting. up to date, logically arranged, and teachable. MAS^. I N S T ~ T U TOB ~ TBCANOLO(~Y TENNBYL. DAVIS
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CAMBRIDOB, MAEIICWSBFTS
ANNUAL REVIEWOP BIOCHEMISTRY. VOLUME 11. James Murray Luck, Editor, Stanford University. Stanford University Press, Stanford University, California, 1933. viii 564 pp. 15 X 22 cm. $5.00. This hook is a compilation of a series of reviews dealing with recent advances in the field of biochemistry. It is a continuation of a volume which was issued for the first time last year under the editorship of Professor James M. Luck of Stanford University. The various chapters are discussed under the following headings: Permeability; Biological Oxidations and Reductions; The Chemistry of the Carbohydrates and the Glycosides; The Chemistry of the Amino Acids and the Proteins; The Chemistry and Metabolism of the Compounds of Sulfur; The Chemistry and Metabolism of the Nucleic Acids, Purines, and Pyrimidines; Carhohydrate Metabolism; Fat Metabolism; The Metabolism of Proteins and Amino Acids; The Metabolism of Creatine and CreaOF OROANIC COMPOUNDS.A YEAR'S COURSB CHEMISTRY tinine: Mineral Metabolism-Calcium and Magnesium; The IN ORGANIC CHEMISTRY. James Bryant Conant, Professor of Hormones; Vitamins; Nutrition; The Chemistry of Muscle; Chemistry, Harvard University. The Macmillan Co., New Chemical Embryology; The Comparative Biochemistry of York City. 1933. xii f 623 pp. 44 Figs. 14.5 X 21.5 cm. Vertebrates and Invertebrates; Detoxicatian Mechanisms; 84.00. Plant Pigments; The Alkaloids; Chemical Aspects of PhotoThis is the third textbwk from the pen of the newly elected synthesis; Mineral Nutrition of Plants; The Chemistry of BacThe Biocheriristrv of the Funxi. president of Harvard University, the other two being "Practical teria: Immunochemistrv: ~ > . " l'hece various chapters are discusced by recognized leaders in Chemistry: Fundamental Facts and Applications to Modem Life," by Black and Conant. Mamillan, New York, 1920. and their special fields of work and include Canadian and sku European authors, crpecially Ihglkh and (krman. "Organic Chemistry: A Brief Introductory Course," Mamillan, The most vnluahlc featuresofthehook arr citations from literaNew York, 1928. It is a textbook for a ful-year course and develops the subject along the same general lines as the author's ture which arc cornpiled at thc cnd of each chapter. While there earlier and shorter book. Alcohols are taken yp a t the beginning may be a difference of opinion regarding the scope of the work and the necessity for structural formulas is made apparent, the covered by the respective writers, i t is the conflusion of the reidea of isomers beine introduced a t once: "Tww omoounds viewer that these literature citations a t the end of each chapter ~are really a most important feature of the book. They allow N hich have the same r~mlecularfornauln arc said to be irrrmerj" is a gratifying dcfinition-- for wc may, and often do, know that one t o follow closely the more important advances and offer a two substances are isomers without knowing the structure of plan for literature compilation which is invaluable. At a time e i t h e r a n d it illustrates the logical manner in which the subject when the most rapid advance is being made in scientific work of organic chemistry is presented. First what we know, and dealing with the many problems of biochemistry and the importhen what we infer from that which is known. Alkyl halides, tant relationship of this science t o other-hranehes of biological ethers, and ethereal salts are discussed before the hydrocarbons work, it is absolutely impossible to review all papers that are are considered. "The double band is B convention sienifvinn - , " presented in our journals. The authors in this review have exercised very good judgment to the nrrnnrc ch~mlstthe existence of two carbon atortar, side and have referred more particularly t o the outstanding contribub y side. w r h uf which may add a n additional monovalent atom or group " The more recent drvrlol,mmts of fundnmmwl or- tions, and it is the writer's opinion that the choice of the more ganic chemistry are treated adequately. important publications has been well made. The b w k should "The electron theory of valence is introduced and used t o be in the library of every researcher who is interested in the dethe extent to which it is a t present of value to the organic chemist. velopments of biochemical research. The distinction between polar and non-polar valence in the amYALB UNIVB~SZTY T. B. JOBNSON monium compounds and the electronic structures of amine oxides, Nsw HAVBN, Corrrrecrlcm
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