in ancient educational establishments. Youth will pay again as i t did in the great war, unless science gets decent fair play. Finally the author refers to the deluded victims of our cnriously archaic system of classical education who point to the evils of the world which they have misgoverned, and the terrible consequences of science under their misdirection as proof of the superiority of ancient culture and ideals. Saddy suggests that as a memorial we install in our universities not only a pure faculty of Art which carries an the creative work rather than the languages of our ancestors, hut also a pure faculty of Duty to foster the obligations of the twentieth century rather than the codes and creeds of mythology, ancient or feudal man. A. P. SY ~
~
cult for the hStIUdor to make clear their relation to each other and to the principles involved. At the beginning of each exercise is given a list of the materials and apparatus for the experiments and following the exercise is a number of questions and problems. The hook is well written and directions are dear and concise. Explanations are included where the student could not he expected to know the results of his experiment. I n the opinion of the reviewer the hook is well suited to the purpose for which i t was intended. GEO. W. SEARS
Colloid and Capillary Chemistry. HERBERT F R E ~ N D L I Translated ~~. from the third German edition by H. Stafford Haffield. E. P. Duttan and Company, 883 pp. New York City. 1926. xv Laboratory Manual Arranged to Accompany "Principles of General Chemi~try.~' 25 X 15.5 cm. $14.00. STUARTR. BRINKLEYAND ERWINB. Professor Freundlich, in this splendid KELSEY. First edition, The Mac- work, has set up a standard to which few millan Co., New York, 1926. xiii writers in the subject may hope to attain. 159 pp. 9 figures. 14 X 21.5. $1.50. Adverse criticism of a hook, to the subject
+
+
As the subject of this manual indicates, the experiments are arranged to accompany Brinkley's "Principles of General Chemistry" and frequent referencxs are made to this text. The suhject-matter is divided into 47 exercises of which the last 15 are inorganicpreparations. Five quantitative experiments are included among the remainder. Each exercise is divided into sections which are arranged with explanatory titles that indicate to the student what he is expected to observe. While most of the experiments are of the type usually found in laboratory manuals, the authors have grouped them in such a way that the student should not fail to see their purpose though the principle underlying them is not always so clearly pointed out. Many of them are chiefly informational, giving the student facts without showing their particular significance. This might have the effect of causing the student to look upon his chemistry as a mass of more or less unrelated facts though i t should not he diffi-
of which a writer has devoted the most of his useful life, is out of place. Even the briefest examination of Colloid and Capillary Chemistry will convince one of the soundness of this conclusion. To begin with, the arrangement is very logical and very orderly. Too many texts and reference hooks on colloid chemistry are painfully haphazard affairs. Even' the advanced student has difficulty in seeing the thread of continuity throughout colloid phenomena. Fre'mdlich's hook clears up this maze as the sunlight dispels the mist. The plan of the book is well stated in the Introduction. "The first part of the book will therefore deal with the physicochemical foundations of colloid chemistry, that is to say, with capillary chemistry. the formation and interconversion of phases, and molecular motion. Upon these three foundations colloid chemistry itself will he built up in the second part of the hook." "These three foundations" have been
VOL.3. No. 12
&CENT
well and strongly built. Three hundred fifty-two pages are devoted to them, 315 of which are needed to cover the subject of capillary chemistry. The allotment of so much space to the latter is justified by "the f a d that other expositions of this subject do not exist." For this section of the book alone, the whole book w d d be justified. The following very condensed outline will show the scheme of Freundlich's treatment. The physico-chemical foundations of colloid chemistry. Capillary chemistry. Interfaces. Capillary-electrical phenomena. Properties of interfacial layers. Kinetics of the formation of a new phase. Brownian molecular movement. Colloidally disperse systems. Colloidal solutions. Sols-lyophobic and lyophilic. Gels-lyophobic and lyophilie. Mists and smokes. Foams. Solid colloids. The order of arrangement of the second half of the book is chosen so as to bring more familiar svstems to the attention first. Amin. " . Colloid and Caoillarv . . Chemistrv is interesting. One might fear that, in a work of this magnitude, dreary tables, equations, and hypotheses would be the reader's reward. But Professor Freundlich has so interestingly interwoven these necessary and useful things with the things of everyday life, thiut it is difficult to leave off reading. Colloid and Capillary Chemistry is a veritable mine of information. The exceptionally large number of literature references further enhances its value. Twenty-nine pages of Addenda bring the book right up-to-date. The translation is excellent. Seven plates of photographs of X-ray diffraction patterns, nltramicroscopicobjects, etc., of unusual clearness and beauty add to its interest. One
hundred fifty-seven diagrams are used to assist the explanations. A comprehensive subject and author index rounds out this remarkable work. It is unfortunate that better paper and binding were not used, but these matters are not UEmediable. M. HARINO MALCOLM Kolloidforschung in Einzeldarstellungen. Vol. V. Das Polarisationsmikt.oskop.Seine Anwendung in der Kolloidforschung und in der FWerei (The Polarization Microscope--Its Use in Colloid Research and in the Dyestuffs IuAND dustry), by HERMANN AMBRONN ALBERTF ~ Y Akademische . Verlagsgesellschaft m. b. h., Leipzig, 1926. x I94 pp. 14.5 X 22 an. Paper, 12 Rm.: Board, 13.5 Rm.
+
The authors state in the preface that, according to the statement of a distinguished physicist, eledricity is nothing else than the sum total of all the experiences which we have encountered and which we hope to still have in this life. The same may be said of light, and we can with good grounds make a similar statement for the structure of colloids. In order, however, to widen our experiences in all of the different possible directions, it is necessary to use very varied methods in our researches. This hook has as its primary object the task of pointing out a technic for the study of colloids which has in the past been but little used and which to all appearances can make many new and worthwhile contributions in this field. The methods are not new but have been long used and tested in the fields of applied and theoretical physics and in miuoscopical research. The use of the polarization microscope in colloid research is not common as would be expected if one considers the importance of the contributions wbich it can make. The cause for this apparently does not lie in the lack of accuracy in the necessary apparatus. for such apparatus is readily available and can he easily
