1840
JOURNAL OF CHElMICAL EDUCATION
states of matter. The authors believe that certain marked advantages are obtained by doing this. However, there will prohably be considerable disagreement with this view due t o the prevailing diversity of opinion as t o what is a really logical order of presentation. Certainly i t leads to some questionable prmedures, such as discussing ionic equilibria before discussing the theory of ionization and its wnsequences. Another novelty which is to he highly commended is the consideration of colloid phenomena wherever reference must he made t o such phenomena. Of course there is a separate chapter on surface chemistry, hut the matter is no longer treated as if i t were a totally distinct aspect of theoretical chemistry. This is a decided advantage as it serves t o emphasize the interweaving of natural phenomena. The h w k contains 51 tables of useful data (culled largely from International Critical Tahles) and snficient, although not abundant, references. Interest is aroused by inclusion in suitable elementary form, of such recent developments as Stem's work on molecular rays, para- and, artho-hydrogen, wave mechanics. the Dehye-Hiickel theory, etc. Especially noteworthy are the treatment of the thermodynamic aspects of physical chemistry, the chapters on rates and mechanisms of reactions, atoms, molecules, the activation of atoms and molecules, and the discussion of electromotive force. There is an abundance of new and very pertinent problems. Naturally the size of a hook of this character must not be such as t o diswurage an appetite for study, hut it does seem that a few items might have been included without defeating this object. For instance, there is no derivation of the reaction isotherm, steam distillation is dismissed with a sentence or so. the Harkins' correction on the weight of the falling drop is mentioned by literature reference alone. there is very little on viscosity, and the dissociation of salt hydrates is discussed in two places and that rather scantily. A
OCTOBER, 1932
fuller treatment of the calculations and methods of crystal sttucture analysis would be helpful. The omission of the usual preliminam treatment of fundamental laws, methods for determining atomic weights, etc., may not he regretted hy the student hut certainly is hy the reviewer. These subjects are seldom treated in earlier courses as fully as they deserve. Unfortunately the signs of e. m. f. values do not conform to the most general convention of today. To sum up, this is a very well written, interesting and stimulating text. It implies some things that might well he stated more enplicitly,.but the properly qualified teacher can easily expand upon them himself. The h w k should meet a cordial reception and the authors are to be heartily congratulated. M. HARINO MALCOLM UWlVBRSrrY OP M*EYL*ND
COLLBGB PAAK,MAXYLAND
Unit hocesses and Principles of Chemical Engineering. JOHN C. OLSEN, Ph.D., D.Sc., Professor of Chemical Engineering, Polytechnic Institute, Brooklyn, N. Y.. Formerly Secretary m d President of the American Institute of Chemical Engineering. D. Van Nostrand Co., Inc., New York City, 1932. 558 pp. 171 Figs. 13.5 X 21.5 xiv an. $5.00.
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Professor Olsen, with the help of collaborators, has created the first hook written in English presenting in introduction t o the general field of chemical engineering. The author covers not only the "unit operations" but also certain indnstrial chemistry studies. There are chapters on economics, plant location, materials of construction, and data an chemical equipment design. This last-named subject is a portion of what might he called "chemical unit processes" t o differentiate them from "unit operations" which are almost entirely physical in nature. This hook attempts to give a brief summaryof the entire suhiectatrulylaudable purpose. The result is an extremely in-
VOL.9, NO. 10
RECENT BOOKS
teresting and worthwhile treatise for any student who desires to learn from a single volume what chemical engineering really is. Dr. Olsen and his collaborators are to be congratulated on their motive and the result. The "unit operations" are not as completely covered as in texthwks devoted entirely to this particular subject. This was t o be expected. Fluid dynamics, crushing and grinding, and crystallization are examples of titles that have been omitted. The practical engineer will find certain chapters have been written with him in mindsamething he will appredate. This is especially true of the chapters on evaporation, drydistillation, absorption of gases, and the separation of solids and liquids from gaseschapters, by the way, that deserve special citation bccause of their unusual interest. Many of the prominent industrial processes are described in detail in order to give the student a clear conception of a concrete use for the various unit operations. This idea is carried out particularly well in the chapters on steam-distillation, dry-distillation, and electric heating. The "chemical unit processes" are brought into the chapters on electric heating, catalytic processes, and electrolysis because in these the authors give data on the design, construction, and operation of full-sized equipment within which a common chemical reaction takes place. Mention should be made of the excellent chapter on plant location. The author has treated the subject in a very comprehensive manner. All teachers who have been looking for a book which will introduce the subject of chemical engineering to the student and will supply actual plant problems will be interested in Dr. Olsen's excellent text.
D. B. K E Y E ~ UNIVBRSITY OF ILLINO~S U ~ ~ A NILLI"o,s *.
Chemical Analysis by X-Rays and Its Applications. G . VON H m r s v . Pruf r r w of I'hssical Chemistry, I'niversity of Freibwg. McGraw-Hill
1841
Book Co., Inc., New York City, 1932. v 333 pp. 101 Figs. 15 X 23 cm. $3.00.
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The present volume, the tenth in the series by the holders of the George Fisher
Baker Non-Resident Lectureships in Chemistry a t Cornell University, maintains the high standard of excellence set by those appearing previously. These lecturers are invariably outstanding men in their chosen fields and one can feel sure that their statements are authoritative. Except for an Introductory Lecture on "The Age of the Earth," the book is divided into three veiy distinct, though related, parts: "Analysis by Means of X-Rays." "The Discovery and Properties of Hafnium," and "The Chemical Composition of the Earth and the Cosmic Abundance of the Elements." Part I gives not only the historical development of chemical analysis by means of X-rays with examples of the uses of such analyses, hut detailed descriptions of the apparatms and procedures used, with comprehensive tahles, making this a very valuable manual for any one actually Qing work of this sort. I n view of the importance of chemical analysis it would seem that all chemists and chemistry teachers should make themselves a t least super6cially familiar with methods such as those desnibed here which show promise of displacing s w n the usual chemical methods for large classe~ of analyses. Part I1 gives a highly interesting account of the discovery of hafnium (the author being one of its co-discoverers), followed by a description of methods of separation and analysis and of the chemical and physical properties of the metal and its compounds. I n Part 111 are described and compared the methods used in arrivina - at a knawledee of the relative abundance of the elements in the earth and the rest of the solar ry,tem, with the results obtained. The averaye chemictrv teacher would bc interested only in certain portions of this
