aware of such new techniques. I t should be required reading for anyone starting research in scattering of X-rays or light. DAVID H. TEMPLETON U N ~ V E BOP~ CAL~POANI., ~T~ B e n w ~ L ~C u ,A ~ I F ~ ~ N I *
SILICIC SCIENCE
E. A. Hauser, Professor of Colloid Science, Massachusetts Institute of Technology. D. Van Nostrand Co., Lnc., Princeton, 1955. xii 188 pp. 96 figs. 6 tables. 16 X 23.5 cm. $5.
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T r r ~appearance of this new book highlights again tho growing interest in fundamenthl st~ldiesof the natural occurring colloidal silioittes. This is the third such book to appear in recent years in this country. Whereas Marshall's tre& ment ("The Colloid Chemistry of the Silicate Minerd8," Academic Press, Inc., Xew York, 1949) of the subject is largely from the theoretical standpoint of the soil ohemist, and I l e r ' ~approach ("The Colloid Chemistry of Silioa and Silicates," Cornell Univemity Press, Ithaca, 1955) reflects the utilitarian interests of the industrial chemist (ssevidenced by copious references from the patent literature), Hauser attempts to combine the two approaches and put theory into practice.
Perhaps the most interesting and significant aspect of the book i s the general theme itself whieh is apparently always in the forefront of the author's mind. As TV. A. Weyl points out in an introductory chapter, Hauscr emphasizes t h a t in order for z. substance t o develop colloidit1 properties the substance does not need to be finely subdivided in all three dimensions. As soon as the thickness decreases beyond a critical value in one dimension, new properties are developod which cannot he fully understood on the basis of conventional concepts of chemistry. Thus the inberest in thc natural occurring fibrous and flnke-like clay minerals of colloidal dimensions. Hauser correctly wnsiders tho strncture and oompasition of the colloidnl silicatei as most fundamental and is remarkablv successful in relating properties to them. The witer, however, was very surprised, to see reference to the Mehmel structure of hallagsite, which is no longer held in repute, and also to see discussion of the Gdelman structure of montmorillonite, whcreas the Hofmitnn structure has gained more widespread acceptance. Likewise, he doubts seriously the presence in saponite of magnesium substituting for silicon in positions of tetrahedral coordination. The most disturbing aspect of the hook, holr-rvcr, i s its gencrnl lack of documentation. I n numerous instances entire paragraphs are quoted verbatim, but more frequently the author dr:lws significant conclusions for whieh it is (Continired on page A518)
JOURNAL OF CHEMICAL EDUCATION, NOVEMBER, 1956
