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Chromel-constantan thermocouples with temperature in degrees Celsius (centigrade) and Fahrenheit and elec­ tromotive force in millivolts as the argu­ ments. The tables are based upon the absolute electrical units and the inter­ national temperature scale of 1948. Semimicro

Qualitative

Analysis.

Frank J. Welcher and Richard B. Hahn. vii + 497 pages. D. Van Nostrand Co., Inc., 250 Fourth Ave., New York 3, Ν. Υ., 1955. $6.50. Reviewed by HAHVEY DIEHL, Iowa

State College, Ames, Iowa. Thisfinetext has a good blend of theory, descriptive material, and practice. Part I, theoretical material, 192 pages, is well organized, lucidly written, and modern in approach. Chapter 13 on complex ions is particularly well done. Each chapter ends with sections on worked problems, questions, and prob­ lems. The problems are well chosen, their number is unusually large, and answers are given. Part II, 117 pages, entitled "Ref­ erence," has extensive tables of physical data, a discussion of mathematical oper­ ations, and data on properties of metals and ions. The latter information is presented in tabular form, making for rapid reading and easy comprehension. Part I I I , 150 pages, experimental, carries an introduction to laboratory work and a working direction for sepa­ rating and identifying cations and anions. Extensive use is made of tables and charts. The general impression that the Wel­ cher and Hahn text makes is that it con­ tains an unusually large amount of descriptive chemistry. I t is far short of the paragon in this respect, the McAlpine-Soule version of Prescott and Johnson now so badly in need of re­ vision, but has far more than the mine run of texts on qualitative analysis. As almost inevitable with a new book, a reviewer can find some specific criti­ cisms. The oxygen molecule, being paramagnetic, can hardly have the simple double bond character ascribed to it on page 13. The remarkable hy­ drogen bonding present in the molecule of nickel dimethylglyoxime is ignored on page 169. The structure of the cupric tartrate ion is now known to be differ­ ent from that pictured on page 176. The authors use the term "supernate" consistently throughout. The reviewer at first viewed this with alarm, but later decided that supernate might well prove to be an acceptable com­ panion to filtrate, eluate, and distillate. The publishers have done well with t i e composition, and paper and binding appear adequate. Welcher and Hahn may have set the standard for qualita­ tive texts for the next decade or two.

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Exclusive Varian sample spinner permits fine separation of closely spaced resonances. Complete Varian magnet system available to provide unsurpassed field stability a n d homogeneity. New console mounting puts a l l controls within easy reach of operator. ^

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