366 



NA TURE 



[May 27, 1909 



are devoted to electric railways. The method of 

 giving two tables for the same constant in two 

 separate parts of the book is open to much criticism, 

 and there are one or two obvious mistakes. In the 

 description of the Weston cadmium cell, for ex- 

 ample, the elements are stated to be cadmium and 

 mercury instead of cadmium amalgam and mercury, 

 while in the table of specific inductive capacities on 

 p. 227 the specific inductive capacity of gutta-percha 

 is given as 25, whereas on p. 36 we have the proper 

 value of from 3'3-4'9. The whole of the table on 

 p. 227 might well be omitted. Apart from a few 

 minor defects, which it is very difficult to avoid in 

 a compilation of this kind, the tables appear to be 

 trustworthy, and are readily referred to by the aid 

 of an excellent and complete index. E. VV. M. 



FOOD AND NUTRITION. 

 Human Foods and their Nutritive Value. By H. 

 Snyder. Pp. .\vi + 362. (New York : The Macmil- 

 lan Co.; London: Macmillan and Co., Ltd., 1908.) 

 Price Si. net. 



OUR author remarks that the study of foods is 

 " the oldest, most important, most neglected, 

 and least understood of any that have a direct bearing 

 upon the welfare of man." 



No doubt there has been, and still is, neglect of 

 systematic and coordinated scientific investigation into 

 the many problems which arise in connection with 

 the task of nourishing the human body. Yet a vast 

 amount of work has been done on the subject. The 

 list of books referred to in the present volume reaches 

 the respectable total of one hundred. True, many of 

 them — as, for example, the " Bulletins " of the United 

 States Department of Agriculture — are only short 

 studies of isolated points, but, on the other hand, the 

 list is chiefly confined to American works, and is not 

 intended to be a complete bibliography. Perhaps the 

 indications point not so much to general neglect as 

 to the present stage being one of accumulating evi- 

 dence. By and by, it may be, some dietetic Kepler 

 will discover laws of nutrition which will coordinate 

 the facts better than can yet be done. Meanwhile, 

 distinct progress is being made. 



The opening chapter of the volume is devoted to 

 expounding the general composition of foods. It de- 

 scribes how they are made up of water, inorganic 

 salts, and organic compounds, and how the latter 

 may consist of proteids and fats, starches, sugars, 

 pectose, cellulose, and so on. After explaining the 

 changes which foods undergo during cooking, the 

 author passes to a consideration of the various classes 

 of foods — e.g. vegetables, fruits and flavourings, milk 

 and other dairy products, meat-foods, cereals, condi- 

 ments, and beverages. In each case a short descrip- 

 tion of the article is given, indicating its composition 

 as regards nutrient substances and, generally, its value 

 as a food. Tables are appended which show, for 

 ordinary American foodstuffs, the proportion of non- 

 edllile refuse, water, protein, fat, carbohydrates, and 

 ash, together with the heat-equivalents of the foods. 

 NO. 2065, VOL. 80] 



Naturally in so small a book the information is 

 often meagre, but it appears to be generally trust- 

 worthy. The treatment, though elementary, should 

 serve to make the work a good introduction to the 

 study of dietetics. 



Probably the sections dealing with the digestibility 

 of foods and with dietary studies will be found the 

 most interesting. The author distinguishes between 

 the completeness and the ease of digestion, and sum- 

 marises the factors which influence the two as (i) 

 combination of foods, {2) amount, {3) method of pre- 

 paration, (4) mechanical condition of the food, (5) its 

 palatability, (6) its physiological properties, such as 

 astringency and laxativeness, (7) the individuality of 

 the consumer, and (8) psychological influences — e.g. 

 preconceived ideas as to the wholesomeness or other- 

 wise of the food. On such questions as vegetarianism, 

 the use of " whole-meal " bread, and heavy meat 

 diets, Mr. Snyder takes a moderate and reasoned atti- 

 tude. As regards the last, he maintains that at 

 present the available results are too meagre to justify 

 the formulation of other than tentative standards. 

 " In the matter of diet," he says, quoting Hutchi- 

 son's " Food and Dietetics," " every man must, in 

 the last resort, be a law unto himself .... giving 

 due heed to the warnings which nature is sure to 

 address to him should he at any time transgress." 



C. SiMMONDS. 



THE BODY AT WORK. 

 The Body at Work. A Treatise on the Principles of 



Physiology. By Dr. .Alex. Hill. Pp. xi + 448. 



(London : Edward Arnold, igo8.) Price i6s. net. 

 "T^R. HILL has given us a book at once instructive 

 -'-^ and attractive. He writes for the amateur in 

 science, but men deeply versed in physiology will 

 find much to interest and to learn in his work. 

 There is not a sentence in the book that could be 

 spared, yet, although the reading commands close 

 attention, it never fails to attract and to please. 

 After a preliminary review of the subject of physi- 

 ology, the second chapter, on the basis of life, re- 

 minds one of the great man w'hose name appears in 

 the first line of the chapter, for " The Body at Work " 

 is quite in the style of Huxley at his best. 



The subject is approached from the unit of struc- 

 ture — the cell — through its groupings and specialising 

 of structure and function to form the higher tissues 

 and organs. The importance of the leucocytes, their 

 manner of travelling, of multiplying, and of grouping, 

 is graphically told, and the sections devoted to the 

 blood and circulation in chapters iv. and ix. are 

 simply but most explicitly handled. Amateurs in 

 science can peruse with understanding the abstruse 

 subjects of the functions of the thyroid gland, the 

 suprarenal capsules, and the pituitary body. Diges- 

 tion and dietetics, respiration in all its bearings, ab- 

 sorption and excretion are given in language that reads 

 almost like a fairy-tale, vet with a scientific accuracy 

 and bearing wholly trustworthy. 



Throughout the book the meaning of vital processes 

 is brought out in a fashion which leaves its impress. 



