JOURNAL O F CHEMICAL EDUCATION
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The book is well documented and contains a elossarv " of ooticel terms. This s m l l book oresents s, critical survev of the menent A
pitfalls and limitations of the method. It is felt that the authors have performed a valuable service in carefully evaluating what should become an increasingly important branch of metallography. The book is recommended to all those interested in the mioroscopical examination of metals, alloys, and ores. W. WALKER RUSSELL
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SEMMICRO QUALITATIVE ANALYSIS
Paul Arthur, professor of Chemistry, and Otto M. Smith, Prafessor Emeritus of Chemistry and Director of Research Foundation, both of Oklahoma Agricultural and Mechanical College. Third edition. McGraw-Hill Book Co., Inc., New York, 1952. xi 285 pp. 27 figs. 8 tables. 15.5 X 23.5 cm. $4.
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SINCE semimior0 qualitative analysis is the subject of almost as many texts as is general chemistry, i t is difficult for a teacher to appreciate a new text unless it. shows marked advantages over its fellows. Changing texts in qualitative analysis is a major operation inevitably involving some retooling of laboratory locker equipment and extensive change of reagent solutions. Hence, the teacher of analytical chemistry is inclined to look with something less than enthusiasm a t "another qual. text." In this reviewer's opinion this text offers no particular advantage over many others in the field. The theoretical portion of the text, comprising the first ten chapters, introduces the reader to physical-chemical principles of ionic equilibria. The theoretical material is developed more in accord with the needs of a physical chemistry course than with those of a qualitative analysis course. For example, the principle solubility product which is encountered very early in the labacttory is discussed in the text after the material on ionization of acids and base8 and buffer calculstion. I n view of the physical chemical approach, it was surprising to h d the mention of activity and activity coeffioient limited to afootnote. Oxidationreduction reactions are not considered until the tenth chapter where the ion-electron method for balancing is used hut not explained. The chapter on complex ions is inadequate. The idea of mawimum coordination is not developed and the chapter is without one mention of ehelrttes although liberal use is made of organic reagents in the laboratory portion of the text. Illustrstive of the lack of coordination of lecture and laboratory material we find the complex HgL-mentioned in the chapter on complex ions, hut HgCL in the laboratory portion. The text also suffers from a lack of chemical equations, especially those of the metals with the many organic reagents used and those of anion reactions generally. The mistakes found include: Cuaa+should be Cut (p. 132) Co(OH)* NHs yields Co(NH&" not Co(NH8).'-'- (p. 225) Formula Ni dimethylglyoxime should indicate 4 Ni-N bonds rather than 2Ni-N and 2Ni-0 honds (p. 233)
1950. As in the earlier volumes the information is presented in the fonn of short abstracts of experimental procedures. The reactions are arranged according to the elements whieh are to he bonded and according t o the type of reaction (i. e., addition, rearrangement, exchange, and elimination). A apecial symholism is used for the reaction types; readers who master the simple rules for assigning a "reaction symbol" are able t o locate reactions in the book without reierence to terms auch as the Beekmen rearrangement, aldol condensation, or Malaprade reagent. However, a conventional index, listing "name" reaetions, functional groups, general classes of compounds, resgents, etc., is provided for those who prefer not to make use of the "reactions symbols." A specific illustration-for example, h d i n g information on the conversion of the carbonyl group to methylene--will serve to describe the use of the cataloguing scheme, as well as the kind I 0, of information presented. First the reaction symbol, HC T referring to the formation of the carbon-hydrogen bond (HC) by exchange (JT) with oxygen (O), is constructed. Then the page on which such processes are treated is located. This may be done directly or with the help of the table of symbols st the back of the baak. At the proper place in the baak we find abstracts of pertinent work on the Clemmensen reduction published in 1949 and 1950 by Leonard and by Clemo. Also wo note references to the Wolff-Kishner method, and are reminded by a reference to Plattner (1949) and to others that the keto group attached t o an aromatic system may be converted to methylene by catalytic hydrogenation. In this particular section, it would have been helpful to the searcher if a cross reference were provided to the twadtage process of transforming carbonyl to methylene, involving thioketsl formation followed by Raney nickel desulfuriza1 S. tion. This last method is found under HC T The reader would be led to the same abstracts by looking in the conventional index for such entries as Clemmensen, Kishner, Walff-Kishner, (Raney) nickel, zinr, etc. Theilheimer's occasional failure to include Kekul6 double bonds in the structural designation of aromatic systems is not the best practice and can lead to unnecessary ambiguity. Thus we find a structural formula on page 23, written a-ithout double bonds, which does not distinguish between a furan and a tetrahydrafuran derivative. Only after reading the abstract does it become clear that a furan compound is intended. However, this and other minor criticisms do not detract significantly from the value of the book. I t may he predicted that this volume of synthetic methods will find its place with its earlier counterparts as s standard secondary source. Parenthetically, it is interesting and gratifying to realise that a group of chemical industries is sponsoring the Theilheimer series. I t hits been pointed out before that substantial support by industry for other worthy publications, such as Chemtcal Abstmcts, would be highly desimble. WALTER J. GENSLER Bosroa U N ~ V E R ~ ~ T Y Bosrow. M A s a A o ~ a s m T s 3
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SEAWEEDS AND THEIR USES
V. I. Chapman, Professor of Botany, Auckland University College. Pitman Publishing Corp., New York, 1952. xiv 52 fiw. 20 plates. 14.5 X 22 om. $6.
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SYNTHETIC METHODS OF ORGANIC CHEMISTRY. VOLUME 6
W . Theilheimer. Interscience Publishers, Inc., New York, 387 pp. 16.5 X 23.5 em. $12.90. 1952. xi
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T H Esixth volunw of this now familiar anrrual a w w y of orgarric reavrlorc incluclrt mntrrinl taken from the litwaturr of 1949 will
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THE fist of the nine chapters cover the occurrence and distribution of seaweeds. This is well covered in an interesting manner for the various sections of the globe with emphasis on the more important seaweeds and the zonation in the various regions. Sketches of s number of seaweeds are included. Unfortunately, previous publications of which the author depended for information on the distribution of Afacrocystis pyrifera along the Pacific Coast are mistaken s s to the distribution of the species. The commercial stands of Macrocy8tis pyifera are found in s. limited r~gionalong the California. and
APRIL, 1953
215
Baja California costs. The superficially similar Macrocystis found farther north is the noncommercial shallow water plant, illaeroeystis intey
