for Optional Work, and Organization of the Unit in Question Form. Before discussing these topics briefly it may be helpful t o quote a few sentences from the preface of the manual which will state some of the beliefs and aims of the authors. "Mastery of subject matter, growth in knowledge of how t o study, and training in self directed work and in initiative are large factors in the learning process, for which definite provision is made in LABORATORY UNITSIN CHEMISTRY. . Teachers of chemistry recognize three major problems: (1) how t o relate the laboratory work t o the study of the text: (2) how to adapt the material of their science and the work in the classroom t o the individuals in a group; and (3) how t o test the important 'outcomes' of teaching. To help in solving these problems successfully the authors have brought together in LABORATORY UNITS IN C n e m s ~ n Ya combination of laboratory experiments and directed study activities, as a complement of CHEMISTRY AT Won5." The "Question Survey" of each unit consists of a series of questions which may be answered during the study of some of the experimental work, which the student may sometimes answer out of his general knowledge, or which he may be expected t o answer on the basis of a combination of reading, general observation, and study of the material in the unit before him. I n general, these questions are very goal and if answered carefully would represent an understanding of the material a t hand. The "Study Outline" of each unit is composed of various "Topics" and "Directed Study" for the topics. Some of these topics would require some experimenting and a good deal of outside study on the part of the student and should result in the acquiring of a large amount of information. Some would require knowledge based on observations a t home, in shops, factories, and elsewhere in addition to that obtainable from bwks. The section in each unit on "Optional Work" indudes a series of questions which are headed, "Do you believe?" At the close of each unit the student will find a series of Helpful Suggestioni for the study of material which is intended t o bring him to a condusion in regard t o his belief on the question before him. A few of these questions selected a t random from various units may help t o make this part of the unit clear. A few of them Nn, "Do you believe
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(a) That Seheele was the first person actually to see a gaseous element? (b) That golden hair can be made through chemistry? (To try to find an answer to this the student is told t o bleach hair with hydrogen peroxide, and so forth.) (c) That Moseley's discovery of atomic numbers was greater than Lavoisier's discovery of the cause of fire? (d) That bromides and iodides are salts-?' Many of the questions included in this"0ptiond Work' 'seem to the reviewer to he much less valuable than they might be. Or, a t least, it seems to the writer that the heading. "Do you believe" is a less helpful approach than some other might be. The section of each unit entitled "Unit Readings" contains an excellent and fulllist of readings taken from awide range of books and journals which the student should find interesting and helpful. Next in each unit comes the section headed "Problems." Thrw arc cornposed of the directions and reporr sheets fur the exprrirnrntal work of each unit. These erperimrnts follow rather rlowly the clarrical experimrnts for a high-school text with a somewhat larger number of the type that may be classed as experiments in organic chemistry, household, or every-day chemistw than is customarv in many texts. A number of them emphasize practical applications of chemical principles. These pages contain many blank spaces for the report on the experiment and the answering of questions. Immediately after each experiment, which is called a problem, there is a section called "Self Test" for the problem. This work is intended t o test the student's ability to think scientifically. I n this section a problem. a fact discovered by experiment, is stated. Following the statement of the problem is a series of statements containing the correct answer to the problem. The student is expected to find and check this correct answer. Another series of statements includes among correct and incorrect statements the reason for the
correct answer. The student also finds and checks the c m e c t one of these. This completes his test of his own ability t o "think scientifically." I n other words, the method used in this part of the unit t o test the student's ability to think scientilically is the reading of statements prepared by some one else and the checkine of the one that seems to fit the case. He does not have to formulate any questions himself, visualize reasons and words of his own "making," or express his thought in a statement of his own. He merely runs over statements of another and checks two of them. The reviewer wonders about the consequences of giving the students the impression that "scientific thinking" is as easy as this. The last material in each unit is called "Organization of the Unit in Question Form." This consists of a series of questions t o be answered as "true" or "false" or auestions with blanks to he filled in with a word or two. These &e intended t o help the student summarile the points brought out in the experiments of each unit. The manual, LABORATORY UNITSIN CHEMISTRY, nmtains an abundance of material to meet the needs of the most rigid highschool course. The book is quite free from actual errors, hut is much less free from the loose usage of words. It seems t o the reviewer that this careless use of words is not far from actual error and is particulnrly unfwtunate in a book intended for the studcnt just beginning to acquire a sriernifw vocabulary. lo vicw of the fact char the modern intrvretation of the structure of the atom is presented and used in a number of questions one is surprised to find oxidation referred t o as a gain of oxygen and reduction as the reverse of this. And, one can hardly excuse even one such error as the following: Hydrochloric acid is used for the preparation of chlorine "because the hydrogen of the acid may he removed by oxidizing it to water, leaving the chlorine in a free state." Aside from the rather prevalent loose usage of words. perhaps the most adverse criticism the reviewer might pass is one on the order of presentation of material which does not seem very consistent with the purpose of developing the reasoning ability of the student. For instance, the nonmetals, the chemistry of which is more difficult than that of the metals. are studied before the metals, thus making the work on non-metals more largely memory work than necessary. I t is diffieult, too, t o understand what the authors expect by way of equation writing because one finds, for instance, the simple equation for the reaction between silver nitrate and hydrochloric acid in water solution written out in detail with the names aboveeach compound pages after the student has been asked t o write the equation for the preparation of hydrogen peroxide and after he has been expected to "explain the bleaching action of chlorine." Although this manual seems less good in-many respects than the classical hooks of McPhersan and Henderson i t is a manual which is, by no means. too easy and is one that will interest many of those looking for something rather new in high-school lahoratory outlines for chemistry. But one who knows the former highschool bwks of the above authors will feel that this is not a wholly worthy attempt t o "modernize" the older hooks. And one hopes that a revision of LABORATORY UNITSIN CHEWISTRY will result in a mare careful use of terms and in some rearrangement of material which will lift more of the work above the level of a memory basis. H. H. FILLmGEn ~
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HOLCWBCOLL~~OO HOLLTNS, VIRGINIA
A SYSTEM OF CHEMICAL ANALYSISI1(IR THE COMMON ELEMENTS. Ernest H. Swift, Ph.D., Associate Professor of Analytical Chemistry, California Institute of Technology. Prentice-Hall Iuc., New York City. 1939. xxi 589 pp. 15 X 23 cm. $4.25. This addition t o the well-known series of text and reference works of the Preutiw-Hall Chemistry Series edited by Wendell M. Latimer is the result of ten years of development and practical investigation of the serviceability of "an analytical system which would provide not only reliable and sensitive qualitative informa-
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tion in regard to the constituents present in the material being analyzed, hut also, without an undue expenditure of time or labor, sufficient quantitative information to eliminate in many cases the need for further quantitative determinations." This text isdivided into three parts: Part I, one hundred fortynine pages, "The Preparation of Standard Solutions"; Part 11, two hundred 6Fty-four pages. "The System of Analysis for the Basic Constitnents"; and Part 111, ninety-three pages. "The System of Analysis for the Acidic Constituents." I n addition there is an Appendix, fifty-five pages, consisting in a suggested course of instruction, questions and problems, reagents and chemicals, tables of solubility products, oxidation potentials, ionization and dissociation constants, and atomic weights. Throughout the text material there are eighteen pages of tabular outlines. There is noauthor index. The subject index of twenty-five pages is very complete. Part I contains twenty-one pages dealing with the analytical balance followed by ninety-eight pages dealing with the preparation andstandardization of silver nitrate, ammonium thiocyanate. permanganate, ferrous sulfate, iodine, thiosulfate, standard acid, and standard base. There is an excellent discussion of the electrochemical significance of oxidation and reduction reactions. Limitations in the use of concentrations in the mass action expressions, and a short discussion of oxidation-reduction indicators, acid-base indicators, and adsorption indicators. The volumetric applications of dichromate and ceric solutions as well as iodates are mentioned hut nct described in actual use. The remainder of Part I consisting of forty pages deals with the principles and applications of gravimetric analysis discussed under the headings of solubility etTects, co-precipitation, character of precipitates, and the filtration of precipitates. Since the procedures of estimation in the quantitative determinations are practically exclusively volumetric in principle the discussion of precipitation is directed mainly t o the qualitative procedures of the separation of the basic constituents in the sample. Part I1 consists of a system of qualitative analyses for the basic constituents which is largely conventional and does not avoid the use of hydrogen sulfide and includes only the commonly included constituents. Following each qualitative separation a quantitative scheme of analysis is described, in most cases a volumetric procedure. Methods are selected which emphasize speed rather than precision. This feature of the text is unique and forms the basis for the title page description, "A System of Chemical Analysis (Qualitative and Semi-Quantitative)," The material of Part I1 is exceptionally well organized, complete, and exacting. The theoretical considerations are emphasized and the material, both qualitative and quantitative, is replete with experimental studies of limitations in accuracy and trial applications. Part 111deals with the aci ic group separations, identifications, and estimations. This section deals with th$ preparation of the solution for analysis and preliminary tests, the detection of oxidizing and reducing ions the cyanide, halide and oxy-halogen groups as well as the sulfate, sulfite, oxalate, fluoride and chromate ions. The estimation of these various constituents then follows and the treatment in this part is along the same lines as that in Part 11. The Appendix consists of material appropriate to the text as a whole. The table of Mold and Formal Reduction Potentials is the most instructive the reviewer has found from anv source. ,~ This sy9tern of chemical nndysis is a dislinctly new departure in the field of inrtruction in qualitativc and quantirativr analysis. Thc prinriple of semi-qunotitativc estimation following qualitative separations following the usual schemes may be expected to show an iduence toward greater precision in the qualitative separations. The iduence of this new system as related to the teaching of quantitative analysis might he predicted to have an undesirable effect. I t is contended in this course of instruction that the qunntitative proredmr? are as acctmtc a? the preceding qualitativc separations. The s:me quantitative dcteminations apart from thc previous qualitative selvarations in gencml would certainly not meet with approval when compared with other more suitable and precise procedures. By the proposed new scheme the classroom hours devoted to qualitative and quantita~~~
tive analysis instruction may he lessened when compared to present practice. For this reason the new scheme might prove popular in the case of such groups of students as premedical, or agricultural classes, or chemical engineers. The number of adoptions of this text into teaching practice is speculative. The teaching skill required t o successfully supervise its introduction would of necessity be of a high order. The author of this text gives evidence of a thorough knowledge of the fields of qualitative and quantitative analysis. The references cited are numerous and well chosen. The treatment is strictly up-todate, and many recently developed procedures which are outstanding developments are included. The author does not hesitate t o include procedures in the use of perchloric acid which are undoubtedly better than substitute procedures. These include destruction of organic matter, solution procedures. and separations and determinations in the field of the alkali metals. I t is refreshing t o see use made of the iodine monocbloride reactions which have been previously generally ignored in quantitative texts and to find distillation procedures other than the Kjeldahl nitrogen determination recommended and employed. One of the most valuable aids to teaching which this text introduces is the system of cross references t o various portions of the material by use of letten, figures, and Roman numerals, and combinations thereof. This system recalls the type of treatment in the volume, MET~ODS oa ANALYSIS OF TEE A. 0.A. C., but its use seems t o he more effectivethan in the case of the latter reference. The text has illustrations and diagrams which, while not numerous, are well done. The publishers have composed the material in an attractive, efficient manner and the contents are remarkably free from typographical errors. A few errors only were noted although no particular search was made. On page 89 the voltage given for the oxidation of ferroin is -1.2 volts instead of -1.14 volts. On page 86 divalent iron is oxidized to trivalent iron which is marked as if divalent. On page 268 Boedyreff occurs instead of Boldyreff on the last line. Teachers of both qualitative and quantitative analysis should not consider their library complete without this text. A thorough study of its new innovations may be expected to stimulate thought and effort in both fields of stpdy, in research and teaching. The thorough examination of its contents may develop into a surprising nu&ber of adoptions of the text in university and college teaching. The author is t o he commended for his bold departure from the usual conventions and the thorough treatment his text has attained.
G . FEEDERICK Smra UN~YBRSITY OF IUINO~S U e e m b . ILLINOIS
GASANALYSIS. A. McCulloch. H. F. and G. Witherby, Ltd. W.C. I, London. 1938. 166 pp. 14.5 X 22 cm. 7/6 net. The book is intended to meet the need of a short text suitable for students taking laboratory courses in fuel technology. I t presents a condensed version of m-aterial originally published in adequate detail. Its chief interest to American readers lies in the brevity with which the English technology is reviewed. This is done chiefly by the description of five types of apparatus which are said to meet the requirements of the examination of practically all technical fuel gases. The apparatus are: Bunte, Orsat, Buckley-Sinnatt. Bone and Wheeler, and Haldane. Of these, the Bone and Wheeler is worthy of serious consideration on the part of American readers, who otherwise are more fortunate in the manner of available apparatus and technic. I n addition, there are brief chapters on Absorbents. Combustion. Miscellaneous Determinations, Calorific Value, and the usual . Without considerable assistance from the Appendices. instructor, the hook would scarcely serve as a laboratory manual. or as a sufficiently comprehensive text. MARTINSHEPHERD
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NATIONAL BOWAU 01 STAND~PDS WISR~NOTON. D. C .
