RECENT BOOKS CHEMICAL ANALYSIS OP FOODS AND Foon PRonums. Mowis B. Jacobs. D. Van Nostrand Co., Inc., New York City, 1938. xxii 537 pp. 15 X 23 cm. 56.00.
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While this book does not cover all of the subjects included in the A. 0 . A. C. Methods of Analysis (as, in fact, i t need not do) it is broader in scope than a textbook need be. The reviewer agrees that it can serve "as a manual for manufacturers for control work," hut as one who has taught food analysis for many vears he does not recommend it for use "as an educational text." It is rare that the preri.;im of a method is tnmtionnl, nlthcmgh. on ihc other hand, the author does couniel a r c in rlmnipularim such as, "On cream-testing scales which are in proper workinn condition and of proper sensitiveness weigh nine grams" (page 168) and "The protein content may be estimated by determining the nitrogen content in an accurately weighed portion . . " (page 189), the italics are the reviewer's. Upon perusal of the tables of data one is impressed by a lack of critical selection in certain instances. For example, Table 34 which purports to give the "Constants of Florida Oranges," neither bears a reference for authority nor gives any idea as to how many samples were analyzed to produce the data. The reviewer feels that this sort of tabulation may be quite misleading and he knows that it is definitely misleading in this case, where the weight of orange is given as Mar. 229 g. and Min. 184 a. (these numbers are erroneouslv transuosed in the table) and juice weight as Max. 99 g. and in. 64 g. These data ap&y to small-sized oranges. The author, knowing that oranges come to the market graded to size, should have qualified this table by stating the size of the oranges or a t least noting that they were of small size. Another example, but of a different sort, is found on page 279 where an analysis of Irish moss is given. It lists "available" and "unavailable" carbohydrate and "titratable aciditv" without definition of these terms a i d the latter six lines of data in the desniption could be better expressed in but two. The effect of the dizzy whirl of a centrifuge is noted on page 176 where, "If 5 cc. or 5 g. of cream are shaken with 5 cc. of a mixture of benzene and alcohol and the mixture is centrifuged for a short period, reconstituted cream will throw up its butter f a t . " Any one with a sympathetic attitude toward the cream will agree that its behavior was normal under the circumstances. On page 245, where the author undoubtedly meant to convey the information that the hydrolysis products of rafhnose vary with the conditions, he states, "On special hydrolysis it yields, a t times, a mellibiose residue and a t other times a sucrose residue." The reviewer commends the book because it includes "certain of the newer aspects of food analysis such as the chemical assay of vitamins, the detection of improper pasteurization of milk, the homogenization of milk, the detection of gums . . . " and as the author states, it should "prove useful in regulatory laboratories, both governmental and commercial and as a reference particularly in those subjects treated herein which are not treated in other texts in the subject." ARTW, T a o ~ n s ~
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Twenty-nine articles have been selected for inclusion in this second volume. Some twenty of these are accompanied by brief biographical sketches or explanatory comments. A glossary of one hundred twenty-nine terms is included. Half of the articles deal with industrial applications of or~anicchemistry, while the remainder is divided about equally between theoretical, historical. and medical chemistry. The only criticism the reviewer would make with the distribution is the failure to include a t least one article on the interpretation of organic reactions in terms of modern theories of valence. Fieser's article an "The Structure of Naphthalene" [J.Am. C h m . Soc., 57, 1459-64 (1935)l is the nearest approach to this important phase of theoretical organic chemistry. Dr. Goldblatt's REAnmGs present the most practical means of introducing large numbers of undergraduate students to the chemical literature that has been suggested to date. The wide use of this book may conceivably result in the removal of organic chemistry from its present position as the most difficult course in colleee. accordiie vote. for students do not .. to vovular . . count c&rt a.h&e interest in the subjuct abo&di ~ ~ A o r si css ELPMFNTARY ORGANIC CIIUIIISTRY is t h ~ ~ g h ~ fdesigned ~ l l y and brill8:kntly crecuted to enhance ~tudentinterest. ~
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RECENTADVANCES IN VOLUMETRIC CHEMICAL ANALYSIS.H. B. Kellog, formerly Director of Laboratories, Amp Research Laboratories, Lefax, Inc., Philadelphia, Pennsylvania, 1938. vi 208 pp. 6 figs. 9.5 X 17cm. $3.00 in Faxide ring binder, 52.00 in paper cover.
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This bwk, while printed in pocket size, is a very complete manual of the mare widely used volumetric methods, particularly of the more recent ones. Directions are condensed, but given with sufficient detail for use by the experienced analyst. The general form followed for each determination is (1) concise laboratory directions, (2) formulas for calculations, (3) list of reagents needed, (4) explanatory notes (when these are needed), and (5) hibliography. A commendable feature is the introductory discussion of addbase, adsorption, and oxidation-reduction indicators. I n all cases the treatment of the subject is modern and is written for the practical analyst. The introductory section also contains brief chapters on ceric sulfate, new reagents (oxine, chloramine-T, and spot test reagents) and the preparation and use of zinc and silver reductors. The main portion of the book (pages 54-200) is devoted to procedures for volumetric analyses. Here the topics are arranged in alphabetical order. While most space is devoted t o inorganic analyses, certain organic analyses are treated. In the arrangement of the book it is unfartunate that the sections on standard solutions and on volumetric factors were not segregated rather than alphabetically listed among the determinaCOLIIMBI*UNIV.RS,TY N E W Yoax cirv tions. The number of determinations listed is large; on the whole the selection is good. The chief criticism is that the book is made too compact for READINGS IN ELEMENTARY ORGANIC CHEMISTRY. Edited byL.A. Goldblan, University of Pittsburgh. D. Appleton-Century easy reading, especially under laboratory conditions. The fine Company, New York City, 1938. x 150 pp. 20.5 X 27.5 print used for certain sections is conducive to error. The author is often guilty of carelessness in presentation; particucm. $1.25. larly is this true with regard to building complex sentences Dr. Goldblatt's COLLATERAL READINGS IN INORGANIC CAEM- through the use of the word "and." I t is unfortunate that the ISTRY (1937) filled such a d e f i ~ t need e with teachers of first-year author has not designated those methods which are the official college chemistry that the appearance of a similar work in the ones for referee analyses. Despite these minor disadvantages, field of organic chemistry was inevitable. That this second the book is on the whole excellent, and i t will prove t o he a. volume has made its appearance so soon is due to the thorough- valuable pocket reference book for the practicing analyst. ness with which the author has tested out in his classes for several W. C. PIERCE years the possibilities of parallel readings in both inorganic and TA&UNIVBP.S~TY OP CBIEA(~O orffanic chemistry. Cnrcnoo. I~ulrors
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