Rancidity in Edible Fats (Lea, C. H.) - Journal of Chemical Education

Rancidity in Edible Fats (Lea, C. H.). George R. Greenbank. J. Chem. Educ. , 1939, 16 (8), p 400. DOI: 10.1021/ed016p400.2. Publication Date: August 1...
1 downloads 0 Views 1MB Size
mare significant in distinguishing it from the corresponding atom than is its excess or deficiency of electrons. There are several other statements, also, t o which proponents of the modem viewpoints are likely to take strong exception. The treatment of the "salt effect" (page 84) seems especially inadequate; the statement that "solutions have higher dielectric constants than water and are for that reason better ionizing mediums" could scarcely be substantiated, and the whole trend of this discussion appears to point toward the conclusion that the activity caefficient of a salt is increased, rather than decreased, by the presence of a second salt. The expression "uncommon-ion effect," used in this connection, seems ill chosen; and, in the reviewer's opinion, the use of the term "osmotic pressure" t o represent the tendency of a solute t o leave a saturated solution (page M ) , or of an ion t o be discharged upon a metal (page 149). should be allowed to attain an early extinction. Few typographical errors were noted. Although there will undoubtedly be differences of opinion on theoretical points such as those which have heen mentioned, the book contains much that is valuable. It seems best adapted to colleges in which qualitative analysis is taught not as a portion of the second-semester course in general chemistry, but as a distinct subject occupying a t least a full semester; and it will aooeal .. esoeciallv to teachers who desire a thorouzh eexoosition along classical lines, rather than an interpretation of the most recent developments in this field. ARTHUR W. DAVID~ON

"

.

UNIVBRSITY OF KANSAS LAIYLIBNCB, KANSAS

THE PHASERULE AND ITS APPLICATIONS.Alexander Findlay, Professor of Chemistry, University of Aberdeen; revised with the assistance of A . N. Campbell, Associate Professor of Chemistry, University of Manitoba. Eighth Edition. Long327 pp. mans, Green and Co., New York City, 1938. xv 14 X 21 cm. $3.00.

+

The purpose of this hook, as stated in the preface of the first edition, was to explain, in an essentially non-mathematicalform, "as clearly as possible the principles underlying the Phase Rule and to illustrate their applications t o the classification and investigation of equilibria, by means of a number of cases actually studied." Professor Findlay's success in achieving this purpose is perhaps most eloquently attested by the fact that the present edition is the eighth since the original one in 19041 This edition, like its predecessors, contains a rather full explanation of the phase rule, with detailed treatments (in fourteen chapters) of the applications to systems of one, two, and three components. There is also a good thirty-page chapter dealing with some applications to four-component systems. I n general, experimental data and bibliographical references have been brought up to date, while the Appendix, appearing in earlier editions and describing the generally familiar methods for the experimental determination of the transition point, has now been dropped. Evidence adduced from the X-ray investigation of the nature of solid and liquid phases is stressed throughout, but on the whole this latest edition does not differ radically from the seventh and earlier editions. This excellent monograph should find a place in the private library of any professional chemist. I t will serve also as a useful text for short specialized courses dealing with the phase rule and as an invaluable reference baok in connection with the study of heterogeneous equilibria in any general course in physical chemistry. GEORGE S. PARKS STAN.ORD

UNlVBBSlTY

S T m m a UWIVBRSITY, ~ CAL~ORNIA

RANCIDITY IN EDIBLE FnTS. C. H. Lea, B.Sc.,Ph.D. Chemical Publishing Company of New York, Inc. New York City, 1939. vi 230 pp. 38 figs. 15 X 22 cm. S.W.

+

The object of the book is to present an account of the knowledge concerning the development of rancidity in edible fats and

fat-containing foods. Emphasis is placed on the most scientific aspects of the subject with details of methods employed in diagnosis and correction of faults in processing. The book is divided into six oarts as follows: Part I. The chemistry of the fats. (Twenty-five pages.) Part 11. Rancidity, occurrence, and types. (Four pages.) Part 111. The lesser causes of rancidity. (Eight pages.) Part IV. The action of micro6rganism on fats. (Thirtytwo pages.) Part V. The deterioration of fats by atmospheric oxidation. (One hundred twenty-two pages.) Part VI. Rancidity in dairy products and meats. (Twentytwo pages.) The literature, especially that devoted to atmospheric oxidation, has been thoroughly reviewed, evaluated, and summaries have been presented. The comments based on scientific procedure should he a great help to the layman in evaluating the literature in this field. The work, though short, fills a long-felt need for a review of the rapidly expanding literature in the field of fat deterioration. The book is a reprint of the Department of Scientific and Industrial Research, Special Report No. 46, 16 Old Queen Street, Westminster, London, S. W. 1. GEORGE R. GREENBANK

AND EXPERIMENTS IN GENERAL LECTURE DEMONSTRATIONS CHEMISTRY.George Washington Muhlemen, D.Sc., Professor of Chemistry, Hamline University. Burgess Publishing Company, Minneapolis, Minn.. 1938. ix 79 pp. 21 X 27.5 cm.

$1.50.

+

The author attempts in this volume to combine an outline of lecture material and laboratory experiments for first-year students of college chemistry. He recognizes a serious lack of coordination of lecture material with laboratory procedures in inorganic chemistry, and in this manual he attempts to attack this problem. The book consists of one hundred forty-three relatively short individual experiments covering the topics ordinarily studied in general chemistry. Then comes a "Special Descriptive Circular with a compendious on the War Department"-19l%together bibliography. Then follow tables of mathematics, solubility tables and charts; an outline of "Who's Who in General Inorganic Chemistry." After this the last two pages of the publication consist of qualitative procedures and tests for the cations. No work on anion detection is included. The format of the book is not too satisfactory. While space is an item to be considered, the appearance as well as the usefulness of the manual would be greatly enhanced by two changes which the reviewer suggests, first, that a somewhat smaller type be used, and second, that the space between the lines he somewhat increased. The drawings are satisfactory. One point on which the author is to be complimented is the profuseness of reference material. Throughout the baok appear lists of references pertinent to the topics under discussion. I n addition, there are tabulated the names of great scientists, together with quotations from their writings. These are intended by the author, no doubt, to inspire the student and to impress upon him the value of chemistry in daily life. The author makes a strong plea for lecture demonstrations in place of actual laboratory work by the students. This may be advantageous under certain circumstances. The reviewer finds it difficult to be in accord with this point of view. The author, furthermore, justifies his lack of experiments of a auantitative character on the basis that ". . beglnning students fannot and do not derive sufficient benefit to justify the amount of time they require to perform quantitative work." . . The conclusion. then, is that the manual is best suited to the needs of those students who are taking chemistry for the first time. R. K CARLETON

R"P"=:$T?2~2t,","""