4°4 



NA TURE 



[September 23, 1922 



without further reference to the chemical questions 

 involved. 



Again, a brief discussion of the Liesegang rings ob- 

 tained when silver nitrate diffuses into gelatin con- 

 taining potassium bichromate (p. 43), is made the 

 starting-point for many suggestions as to the signifi- 

 cance of these phenomena in explaining stratification 

 in structural features of the cell and even of tissues. 

 In view of our lack of information as to these diffusion 

 phenomena, little significance can attach at present to 

 the analogous appearances in cell structures referred to 

 by the author. 



The physical properties of protein sols and gels 

 are discussed without reference to the reaction of 

 the solution or the iso-electric point of the protein, 

 the fundamental papers published by Jacques Loeb 

 being ignored. Swelling and imbibition remain, 

 therefore, very incompletely treated, and the in- 

 teresting American work upon the importance of 

 pentosans in the retention of water by plant mucilages 

 is also neglected. The author refers, however, in 

 his preface to the continued post-war difficulty in 

 obtaining access to foreign literature, and doubtless 

 these sections will undergo modification in a later 

 edition. 



The subsection upon enzyme action shows a similar 

 lack of arrangement. It is to be hoped that the author's 

 endorsement of Euler's suggestion that when enzymes 

 are active as catalysts during synthesis they should be 

 denoted by the suffix " ese," will not lead to an ex- 

 tension of the practice. His discussion of enzymes in 

 relation to metabolic synthesis is unsatisfactory, but 

 it at least makes clear how little reason there is for such 

 a practice. Without a clear discussion of modern 

 views of the stereo-chemistry of the hexoses, the dis- 

 cussion of the catalytic action of maltase and emulsin 

 during synthesis is necessarily difficult, but it is curious 

 to find no mention of the experiments of Bourquelot 

 and Bridel, which had reached an interesting stage even 

 in pre-war days. An interesting discussion of the 

 action of hormones in relation to stimulus and 

 response appears in this subsection upon enzymes. 

 The subject reappears in a later section under 

 the heading of response to stimulus, and here reference 

 is made to the work of Paal, Ricca, and others, the 

 absence of which in the earlier discussion had aroused 

 surprise. 



The attempt made to base the phenomena of stimulus 

 and response upon physico-chemical phenomena pro- 

 vides some of the most interesting reading of the book, 

 but it would appear hopeless to expect success in such 

 an effort when the subject of the quantitative study of 

 growth rate is compressed into less than two pages at 

 the end of this section. 



NO. 2760, VOL. I 10] 



Scientific Management of Farming. 



(1) Farm Management : A Text-book for Student, 

 Investigator, and Investor. By Prof. R. L. Adams. 

 (Agricultural and Biological Publications.) Pp. xx + 

 671. (New York and London: McGraw-Hill Book 

 Co., Inc., 1921.) 20.?. 



(2) Organised Produce Markets. By Prof. John George 

 Smith. Pp. ix + 238. (London: Longmans, Green 

 and Co., 1922.) 12s. 6d. net. 



(3) Agricultural Co-operation in England and Wales. 

 By W. H. Warman. Pp. xi + 204. (London: 

 Williams and Norgate, 1922.) 55. net. 



(4) Rural Organization. By Prof. W. Burr. Pp. 

 xiv + 250. (New York : The Macmillan Co. ; London : 

 Macmillan and Co., Ltd., 1921.) 12s. net. 



THE volumes before us emphasise the fact that 

 farming involves two distinct kinds of operation, 

 the production of crops and animals, and the marketing 

 Qf the resulting commodities. Scientific investigators 

 have in the past confined themselves almost exclusively 

 to production, this being the side that involves the 

 soil, the growing plant and the living animal, and with 

 these almost all the sciences at present studied ; it is 

 quite evident, however, that there is a wide field for 

 the economist in the marketing problems that will 

 amply repay study. 



(1) Prof. R. L. Adams deals exclusively with 

 American conditions ; his book is of a type that is not 

 produced in this country, the old Fream in the past 

 and some of the Oxford publications in the present 

 being our nearest approach to it. It covers the whole 

 range of the farm activities, largely from the economic 

 side, but with constant references to modern improve- 

 ments in production and the scientific principles on 

 which they are based. 



A great advantage of the book is the generous 

 provision of tables of data showing crop yields, costs 

 of production, effects of various factors on costs, on 

 income, etc., with references to the original sources 

 which will be at least equally appreciated. It is these 

 data and references which give the book a special 

 value to the teacher in this country, for he is thus 

 enabled to ascertain how the values have been arrived 

 at and how far they can help him in his work. 



(2) Prof. J. G. Smith, of the Faculty of Commerce 

 in the University of Birmingham, sets out in his book 

 the general characteristics of organised markets and 

 the broad principles involved in marketing operations. 

 Considerable space is devoted to wheat and large- 

 scale buying operations are discussed in detail. The 

 volume is of interest as showing the extraordinary 

 complexity of the processes whereby wheat is trans- 

 ferred from the Canadian farm to the English consumer. 



