The 6rst edition of Professor Bancmft's played in assisting in the attainment of our present level of civilization." It is useful hook appeared in 1921 and promptly the opinion of the reviewer that the author made a place for itself. The new edition has admirably succeeded not only in is still better although there are no radical showing how chemistry has developed so changes in treatment. The original 345 that it touches every phase of our life pages have increased to 489 of the same but also in telling the story in non- kind. It must be admitted that this is not a technical language and in a very interesting msnner. The book is divided into text for beginners but rather a stimulating sixteen chapters headed as follows: Soli- reference hook for people who already tude; Mental Isolation; Allies of the Sun; know a good deal of colloid chemistry. Food and Famine; Contributions of The author is gifted in his ability to quote Chemistry to Cloth and Clothing; Deco- the vital statements from research papers ration-Escape from Monotony; Metals, and to offer keen comments on the same. The chemist who is looking for a rethe Master; Materials of Canstruction; Permanency of Possessions; Health and search problem or for additional light on Sanitation; Power; Abolition of Drudgery; a problem finds this hook a gold mine. Chemistry in National Defence; Chem- One may not agree with all the sparkling istly, a Tool; Analysis and Synthesis; The ideas tossed off so easily by Professor Trend and Purpose of Modern Research. Bancroft but an hour with the hook is In the first three chapters the reader is certain to stimulate the flow of one's own told bow isolation, both mental and physi- ideas. We need such books. The author himself regrets that his cal, has been banished and of the part chemistry has had in its accomplishment. chapter on Nan-aqueous Colloidal SoluChapters four to thirteen, inclusive, show tions is so short. There has been t w how chemistry has touched the various little resemch in that field. The treatphases of our lives to give us the security ment of the Electrical Properties of Coland leisure we now possess, while the last loids has been considerably expanded and three chapters give an indication of how there is more about Stability and other topics. the chemist works. On page 18 a. reference to Williams' While the evident aim of the book has not been to discuss the chemistry of the paper, J. Soc. Ckem. Id., 43,97T (1924), difIerent procMses hut to show the Part would have been helpful. Williams played by chemistry, the descriptions, studied the separation of vapors by silica however, are dear and give a good general gel. On page 18 again it might he stated idea of the chemistry involved. Many that Holmes and Anderson removed iron subjects are touched upon and many de- oxide after 6rst drying the iron oxidescriptions are included though very little silica gel to a more or less rigid condition. detail is given concerning methods. A This precaution prevents wllapse of considerable number of full-page illustxa- capillary walls. On pages 18 and 45 tions showing modern chemical processes Reyerson's clever method of metallizing silica gels might be mentioned. J. Am. is interspersed through the text. Chem. Soc., 47,610 (1925). On page 196 GEO.W. SEARS "aluminumUm' should he "alundum." The discussion, an page 164,of Penin's colloid Applied Colloid Chemistry. WILDERD. atmosphere is admirably sane. BANCROFT. McGraw-Hill Company, In short this is a book that every wlloid New York, 1926. Second edition. ix chemist must have. 489 pages. 13 figures. 14 X 19 HARRYN. H o ~ m s cm. $4.00.
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