method. Hippuric acid is made physiologically as an example of detoxification in the body, an experiment that always interests students. The benzoin-bend-benzilic acid experiment is a doubtful choice for inclusion in a curtailed preparative course. I t contains references to pinacone and pinacoline, names no longer considered desirable. The preparation of benzyl chloride and that of anthranilic acid both require chlorine gas, which is in any case hazardous and, if a cylinder of liquid chlorine is not available, decidedly inconvenient. There appears to be no good reason why bromine should not be used in these experiments. The student would readily understand why chlorine is used industriallv. ,. and whv the substitution was made for his lahoratory work. The preparation of ethyl recarcinol illustrates well the Nencki condensation aud thr. Clcmmenscn method of reduction. The experiment on diphenylthiourea, phenylisothiocyanate and triphenylguanidine, a favorite inclusion in older manuals, does not seem a valuable addition to a restricted course. The final experiment, the preparation of indigo from benzaldehyde, requires an expansive reaction scheme to represent the unusual rim-closure involved. and is so snecial a . orenara" . tion as to have little vnluc except pcrhnps for advanced students. The second part of the manual, devoted to the presentation of an nbbrcvlated zchcme of qualitative organic analysis, is introduced by preliminary remarks on small-scale laboratory operations. There is here some repetition of material in Chapter I1 (Important Laboratory Operations), and some further repetition of the same kind occurs in the introduction to the preparation of derivatives. It would seem more consistent to mass all special information as to operations on an analytical scale a t the start of the qualitative section, or even to include it in Chapter I1 p r e ceding the entire laboratory course. Methods for handling small quantities of material are frequently needed in preparative work. The chapter on "Analytical Methods" includes quantitative procedures for determination of specific gravity, neutralization equivalent, and saponification equivalent. In the qualitative tests far elements two paragraphs are devoted to detection of possible cyanamide formed in the nitrogen test, though it is encountered "only relatively rarely." There follow a series of thirty numbered "Special Tests." These include tests of solubility, various familiar general or functional tests, and a number of tests for individual compounds. The inclusion of the Hopkins-Cole tryptophane test serves no very good purpose. The list of compounds appears to contain only one entry to which the test is applicable, via., "a protein," whose identification stops with the recognition of its probable protein character. In the classified lists of compounds which follow there appear some three hundred compounds, for the most part common and inexwnsive. The initial classification into orders is based on elementary composition Further classification, into groups, is bnscd on physical store at rwm temperature, and at one point ~olubilityin water is used to effect a subdivision. I.isted compounds are arranged within the appropriate order and group, in subdivisions based on a similar response to one or more of the general tests. Individual compounds in each division are arranged in the order of increasing melting or boiling points, and each name is accompanied by suggestions as to the numbered tests to be applied and the results to be expected. The list of compounds appears on the whole to be well chosen. Tyrosine and phenylalauine are rather expensive to be given out as unknowns in most schwls, and carbon disultide, phenyl isocyanate, and a-uaphthyl isocyanate are not very good unknowns, especially as the last two are used as reagents. The chapter an "Preparation of Derivatives" presents typical procedures for obtaining certain of the familiar types of derivatives. For each type a table of some individual derivatives and their melting points is given. These tables include derivatives of more than a few compounds not mentioned in the classified lists. The section on derivatives includes a relatively large number of special derivatives for single compounds, some of which could be identified readily by means of one of the general procedures. The presentation of these special derivativu is in some cases unduly expansive, due to explanations with formulas ~
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or reaction schemes. Salts of pseudobenzylthiourea are suggested as derivatives for carborylic and sulfonic acids. These derivatives have melting points which are not well separated. and with improper handling may split out benzyl mercaptan b y hydrolysis, both drawbacks, especially in a student course. The analytical scheme employed in this manual is doubtless satisfactory for the conditions established, i. e., when it is known that the substance is one of a list of several hundred compounds. I t would be of little real help if the list were increased to several thousand compounds. Students unquestionably would derive benefit from experience with class reactions and the preparation of derivatives, as well as from the necessity for analytical thinking, however limited in scope the analytical "system" used, and for this reason the reviewer is inclined to the view that even a brief course is much better than none a t all. If, however, approximately half of the laboratory time is to be devoted to qualitative organic analysis, it seems possible to use a more comprehensive qualitative system, of which several are available. The value of the plan presented, vie., the combination of abbreviated preparative and qualitative analytical courses into a single course, seems debatable. Any arrangement which includes qualitative analysis as part of the instruction in organic chemistry probably has merit, but whether or not it should be introduced by rather drastic reduction in the amount and scope of the preparative work may be left to the judgment of those who design organic courses. The manual is with minor exceptions well and clearly written. and is almost free from misprints. Typography is excellent. though some structural formulas are unduly spread out. The future of this book, and of the idea it represents, may be awaited with interest. E. C. W A G N ~ R UNIYBBSITT OP P B N I I S ~ V A N I I PHnbDBLPBr*,
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PORTRAITS OW EMINENT MATHEMATICIANS. David Eugene S d h , Professor Emeritus of Mathematics, Columbia University. Scriph Mathmtica, 562 West 144th Street, New York City, 1936. 65 pp. 12 portraits. 36.5 X 27.5 cm. 83.00. The portraits included in this portfolio are those of Archimedes (287-212 B.C.), Nicholas Copernicus (1473-1543). Francois ViAte 11540-1603). Galileo Galilei (1564-1642). Tohn Nanier (15501617). RenC ~ e s c a r t e s(159&350), ~ i r ' i s i a c~ e k o n (16421727). Gottfried Wilhelm Leibniz (164G1716). Joseph Louis. Comte Lagrange (1736-1813), Carl Friedrich Gauss (1777-1855), Nicolai Ivauovitch Lobachevsky (1793-1856), and James Joseph Sylvester (1814-1897). The selection for publication was made from a large collection assembled over a long period for the Library of Columbia University hy Dr. Smith, "with a view t o strength, dress, character and achievements. In general, facsimiles of the handwriting of the mathematicians whose portraits appear are from the same collection." The portfolio, which is a fine piece of work, will be of general interest because of the information contained in the biographies and the beauty of the format. One hopes that other collections of a like kind may follow the first one. VIRGINIA GORE
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PRINWLES OF BIOCAEMISTRY.Albert P. Mathms. Andrew Carnegie Professor of Biochemistry, University of Cincinnati. 612 pp. 15 X William Wood and Co.. Baltimore, 1936. x 23 cm. $4.50. The purpose of this teat is, as stated by the author, to present to medical students a caardinated picture of the principal facts and theories of biochemistry in a manner which will correlate and synthesize these facts and theories into a subdivision of a "great science which reveals the 6ner structure and cMrdiited chemistry of the human bcdy." It has been the author's desire, also, to stimulate the imagination of the student to a realistic
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