336 



NA TURE 



[September 9, 1922 



of evolution, but we cannot think of him as failing 

 to appreciate the manifoldness and the subtlety of 

 nurtural influences, both on the individual and on the 

 race. 



Prof. Pearson gives us in his masterly appreciation 

 a useful tonic. " The laws of evolution are open to 

 our study, let us once understand them, and man can 

 elevate man as he has developed his domestic animals 

 — such was the gospel of Galton." Here we are all 

 agreed, Galton was a great man of science and also a 

 social reformer ; and it is a satisfaction to all men of 

 goodwill that he continues to live with such vigour in 

 the Laboratory which he founded. The appreciation 

 has as its frontispiece a beautiful sketch of Sir Francis 

 Galton in 1910, in his " still unexhausted exuberant 

 youth." 



Modern Dietetics. 



Vitamins and the Choice of Food. By Violet G. Plimmer 

 and Prof. R. H. A. Plimmer. Pp. xii + 164. (London : 

 Longmans, Green and Co., 1922.) 75. 6d. net. 



THE old view that a diet was satisfactory, pro- 

 vided that it contained a certain amount of 

 protein and had a sufficient calorie value, has, as is 

 now well known, been modified in two very essential 

 particulars. The quality of the protein is of the first 

 importance ; it must supply the particular amino-acids 

 required by the consumer, and must supply them in 

 the proper amount. Further, there must be present 

 the vitamins, the exact nature and function of which 

 are still unknown, but which are essential for growth 

 and health. 



It is to these two aspects of the subject that the 

 present work is chiefly devoted, the authors having set 

 themselves the task of producing an account suitable 

 for the general reader. In this they have been on the 

 whole successful, although occasionally the super- 

 abundance of facts renders the matter difficult of 

 assimilation. After an introduction dealing with the 

 general principles of dietetics, the subject of the 

 vitamins and their discovery is developed on orthodox 

 lines. The important question of quality of protein, 

 led up to and illustrated by an account of pellagra, is 

 then treated, and the book concludes with two very- 

 interesting chapters on the effect of partial deficiencies 

 in the food and errors in selection of food. In an 

 appendix are given a table of distribution of the 

 vitamins in food-stuffs and lists of food-stuffs rich in 

 each of the three vitamins, followed by a very useful 

 series of notes on food-stuffs, from which a good idea 

 of the efficiency of a diet can be easily and rapidly 

 NO. 2758, VOL. I IO] 



obtained. The book is well produced and contains a 

 number of interesting illustrations. 



It is an inevitable consequence of the rapid progress 

 which is being made in this branch of dietetics that the 

 position with respect to some of the matters dealt with 

 has changed considerably since the book was printed. 

 This is notably the case with regard to rickets, the very 

 recent work of McCollum and of Korenchevsky on 

 experimental rickets in rats, and the remarkable dis- 

 covery of the preventive and healing effect of sunlight 

 on this disease, having come too late for inclusion. 

 Similarly, the large part played by atmospheric oxida- 

 tion in the inactivation of the antiscorbutic vitamin is 

 not made clear. 



The gospel preached by the authors is the orthodox 

 one that safety is to be found in fresh natural food- 

 stuffs, and it is wisely pointed out that instinct, often 

 believed to be a guide to the choice of food, is no longer 

 so under the conditions of modern civilisation. White 

 bread, for example, almost universally preferred in this 

 country, is far inferior in vitaminic potency to whole- 

 meal or " germ " bread, and no instinctive need is felt 

 for green vegetables and salads. The choice of food 

 must be guided by knowledge, and it is pointed out 

 that the distribution of food within the family is often 

 conducted on quite erroneous principles. 



" Children are supposed to be sufficiently nourished 

 if they have bread and jam and plenty of puddings 

 with little meat or butter. It is unfortunately the 

 custom to give to the father or wage-earner the best 

 food, whereas his requirements for heavy manual work 

 are actually better satisfied by the high energy value 

 of bread, jam, and margarine. The child needs the 

 wherewithal to grow, that is protein and vitamins in 

 addition to calories." 



It is in the provision of fresh vegetables to supplement 

 the staple diet of bread, margarine, and meat, all very 

 poor in vitamins, that the chief value of the allotment 

 movement lies (as pointed out by Drummond), and it 

 is to be hoped that the great extension of this system 

 which was called forth by the necessities of the war 

 will be maintained and still further increased in the 

 scarcely less strenuous times of peace. 



Even natural food-stuffs, however, are by no means 

 constant in their content of vitamins. Little is known 

 as yet of the cause of the variations in vegetable 

 products at different periods of growth and under 

 diverse conditions, but that wide variations occur has 

 been definitely proved. In products derived from 

 animals this variation is still more marked, and the 

 authors rightly lay stress on this fact, pointing out that 

 the potency of materials such as animal fats, and above 

 all milk, depends upon the diet of the animal from 

 which it is derived. 



