in this field but the above-mentioned discrepancy in separating Groups IIA and IIB should cause this procedure t o be accepted with caution. CARLOTTO OP MAINE UNIVERSITY
requirements to a marked degree. While the use of qualitative tests would permit the covering of more material, it also would fail to develop technic which is a serious drawback. Such tests a t best leave but fleeting impressions on the mind of a beginner and are soon forgotten. A proper technic developed by the use of Elementary Laboratory Experiments in preparations, however, remains an asset Organic Chemistry. ROGER ADAMS, always and permits the student to adProfessor of Chemistry, University of vance as rapidly in the laboratory as his Assistant theoretical background may permit. Illinois. JOHNR. JOHNSON, Professor of Chemistry, Cornell UniThe preparations are well chosen and versity. First edition. The Macmillan cover very well the simpler typical orCompany. New York, 1928. xi ganic reactions and compounds, with one 305 pp., 19 figures. 14 X 21.5 cm. exception: the proteins. Due to difficulty $1.90. in ~ n.. tests minht .r e.~ a r a t i .o aualitative . be This laboratory manual is designed for used to advantage in this casc. This manual is indeed a very valuable the use of students who are beginning the contribution t o the teaching of elementary study of organic chemistry, and is comorganic chemistry in the laboratory and piled with the idea of placing before the will, no doubt, be most welcome t o many student the more important laboratory engaged in this work. procedures and technic of organic chemJOHNJ. DONLEAW istry. YALEUNIVERSITY The hook is divided into two major parts: The first is devoted t o a clear exposition of the various physical operations Laboratory Manual of Elementary Physiutilized for the .purification of organic MACK,JR., cal Chemistry. EDWARD compounds. Such operations as distillaAND WESLBYG. FRANCE, Ohio State tion, recrystallization, filtration, etc., are University. D. Van Nostrand Company, described and the student, by experi195 pp., with 40 New York, 1928. xi ment, becomes thoroughly acquainted figures. 14.5 X 22 cm. Cloth, $2.00. with the unit orrerations of the laboratory Experience has shown that these experibefore applying the same to the preparaments "are quite workable, that they tion of simple organic compounds. The second part is devoted to the prep- arouse and sustain the interest of the aration of typical organic compounds. students, and t h i t the present selection of Here the student applies the unit opera- topics distributes the emphasis somewhat more appropriately over the entire field of tions of Part I t o the synthesis of pure organic compounds. Detailed directions physical chemistry than has heretofore and pertinent questions accompany each been done in some of the manuals." Less preparation and, in a few instances, quali- time than usual is devoted t o molecular tative tests are introduced to illustrate weight determinations, and in addition t o the type of experiments usually included in simple tests or reactions. Any laboratory manual in organic physical chemistry, Lhe b w k contains exchemistry should accomplish two objects. periments dealing with thermionic tubes, First, i t must train a man in the technic of thermal conductivity of gases, size of molethe science, and second, it must illustrate cules, rate of settling of fine precipitates, clearly the application of reactions learned and light absorption by solutions. There are thirty-five experiments, about twoin the dasrroom to practical problems of synthesis. This manual satisfies the above thirds of which sre expected to be done by
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