5o 4 SCIENCE PROGRESS 



electrochemistry of coagulation, phenomena accompanying changes in the state 

 of proteins, physical properties of protein solutions, hydrolysis of polypeptides and 

 of proteins, enzymatic synthesis of proteins. As an appendix there is a useful 

 account of the technique of electromotive force measurements. Throughout the 

 book a concentration cell is, following the physiologists, called a concentration 

 chain, which jars somewhat on the mere physical chemist. There is a misprint 

 on p. 1 59 and another on p. 367. But these are trivial things. The book is a 

 great one, most stimulating, carrying the reader on. The material is put in such 

 a way as to suggest numerous subjects of research. Without necessarily accepting 

 every one of Prof. Robertson's conclusions, the reader will hardly fail to see that 

 the book stands out as one of the most valuable contributions to applied physical 

 chemistry which has as yet been made. 



W. C. McC. Lewis. 



The Metals of the Rare Earths. By J. F. Spencer, B.Sc, D.Sc, Ph.D., F.I.C. 

 Monographs of Inorganic and Physical Chemistry. [Pp. x + 279, with 

 diagrams.] (London: Longmans Green & Co., 1919. Price 12s. 6d. net.) 



ALTHOUGH a certain small number of foreign works have been written which deal 

 with the preparation and properties of the Rare Earth metals and their salts, there 

 does not hitherto appear to have been any treatise in the English language on this 

 important section of chemistry. 



We are therefore much indebted to Dr. Spencer for his labour and enthusiasm 

 in making available to British chemists the latest work on the subject. 



The chapters deal with such matters as the discovery and occurrence of the 

 rare earths in nature, their fractionation and separation, the special properties of 

 the salts and other compounds of the various earths, and the methods adopted for 

 determining their atomic weights, and an interesting section on the practical uses 

 of this group of substances. 



A special section is allotted to the consideration of the knotty problem of the 

 position of the rare earths in the periodic system, though one seeks in vain for any 

 mention of Soddy's theory of isotopes, which would seem to be very directly 

 connected with the whole question. 



A comprehensive set of indexes is provided, and the fact that the references 

 run into well over 1,000 is an indication of the amount of trouble that has been 

 taken to make the volume really complete. The book should prove of great value 

 to all those interested in the study of the rare earths. 



F. A. M. 



GEOLOGY 



Military Geology and Topography. A Presentation of Certain Phases of 

 Geology, Geography, and Topography for Military Purposes. H. E. 

 Gregory, Editor. Prepared and issued under the auspices of the Division 

 of Geology and Geography, National Research Council, U.S.A. [Pp. 

 xv + 281, with 117 figures.] (New Haven : Yale University Press, 1918. 

 Price $1.25.) 



In large measure the Great War has been a contest of brains, and has required 

 the application of all relevant scientific knowledge for the solution of its problems. 



