332 SCIENCE PROGRESS 



Practical Physiological Chemistry. By Sidney W. Cole, M.A. [Pp. 

 xvi + 405, sixth edition.] (Cambridge : W. Heffer & Sons, 1920. 

 Price 1 6s. net.) 



That little more than a year should have elapsed since the issue of the fifth 

 edition is eloquent testimony~^to the popularity of this work. The present 

 edition does not differ materially from the last one, which was fully reviewed 

 in these columns (July 1920), but it has been revised, and one or two new 

 methods have been introduced which enhance the value of the book. The 

 continued success of the book is assured. 



P. H. 



The Chemistry o£ Plant Life. By Roscoe W. Thatcher, M.A., D.Agr. 

 [Pp. xvi + 268.] (New York: McGraw-Hill Book Company, 1921. 

 Price 1 8s. net.) 



The importance of a knowledge of chemistry to botanists, and more especially 

 to plant physiologists, is gradually coming to be more generally recognised, 

 with the result that some colleges are already providing courses of chemistry 

 especially adapted to the needs of students of botany as distinct from agri- 

 culture. The book under review is the outcome of such a tendency, which is 

 making itself felt also in America, and is compiled from the author's lecture 

 notes on a course of Phytochemistry delivered by him as Professor of Plant 

 Chemistry to the students of the Plant Science group of the University of 

 Minnesota. While acknowledging his indebtedness to a number of other 

 works on the same subject, the author explains that an attempt has been 

 made to arrange the material in such a way as to proceed from simpler 

 chemical principles and substances to those of more complex structures, 

 which results in an arrangement of the groups to be studied in an order which 

 is quite different from what their biological significance might suggest. 

 The author is to be congratulated on producing a very readable little book 

 on the subject which, with the exception of a number of mis-spellings of 

 author's names, is on the whole singularly free from errors. 



P. H. 



The Physiology of Protein Metabolism. By E. P. Cathcart, M.D., D.Sc, 

 F.R.S. (Monographs on Bio-chemistry.) [Pp. iv -j- 176.] (Long- 

 mans, Green & Co., 1921. Price 12s. 6d. net.) 



This monograph first appeared in 191 2. It consisted, in the words of the 

 author, of "a discussion of the more important results published in the last 

 decade and their bearing upon the work of the earlier investigators." 

 Another cycle of years is almost complete, and has added a mass of new work 

 to the abundant literature of protein metabolism ; work associated with the 

 names of Lusk, Van Slyke, Folin, Osborne, Mendel, and many others, chiefly 

 in the United States. These years have brought us a more careful defini- 

 tion of the broad facts of the problem from the greater exactness of the newer 

 methods, some misconceptions have been righted and some perplexities 

 removed, but there has been no fundamental revolution of thought. There- 

 fore the new edition of this monograph, whilst it marshals all the later work 

 in its proper place in the discussion, is little changed in structure. Indeed, 

 one moves with some feeling of congestion amongst the crowd of evidence 

 that has been packed in the small confines of this volume. Happily the 

 author is concerned to paint us a broad view, and, in avoiding undue attention 

 to the experimental study of the metabohsm of particular constituents of 

 the protein molecule, saves his picture from eclipse in a mass of detail. 



If there has been any startling accession of knowledge in this field it is 

 to be found in the fascinating story of the discovery of the " accessory food 

 substances." Ultimately no theory of metabolism may disregard the evidence 



