October 20, 1923] 



NA TURE 



577 



omitted little or nothing up to the date of its produc- 

 tion. It will be found very useful. 



Like most new and far-reaching discoveries, that 

 of vitamins has not escaped the danger of being regarded 

 as displacing or reducing to little importance previous 

 work on such matters as the energy value of food. 

 While it is perfectly true that, in the absence of vita- 

 mins, no amount of food, however great, suffices for 

 health, it is nevertheless equally true that no amount 

 of vitamins can compensate for a lack of energy 

 value. In actual practice, however, there is, under 

 certain conditions in which fresh vegetable food is 

 absent from the diet, more risk of damage to health 

 from this factor than from absence of total quantity. 

 Such, for example, is the position of those populations 

 which live mainly on rice, or in circumstances in which 

 preserved or canned food is the chief article consumed. 



The reviewer is glad to note that the authors have 

 adopted Drummond's suggestion of dropping the final 

 e of the original name " vitamine " and appending a 

 capital letter to express the particular kind of vitamin 

 referred to. This practice is rapidly being generally 

 adopted, since it is, on the whole, more satisfactory 

 than any other that has been advocated. The origin 

 of the name will soon be forgotten and it will become 

 just a name, like " enzyme," which does not suggest 

 yeast whenever it is used. In connexion with the 

 title of the present book, it may be noted that there 

 are other factors of food equally as " vital " as vitamins. 

 The term " accessory factor," sometimes used, is apt to 

 suggest, on the other hand, that these factors are only 

 of subsidiary importance. 



A brief account of the elementary principles of 

 nutrition precedes the main subject. This appears 

 to contain all that is needed for the purpose. We may 

 ask, perhaps, if water, salts, and vitamins are to be 

 added to the traditional fats, carbohydrates, and pro- 

 teins as necessary constituents of a diet, why omit 

 oxygen ? The first chapter is devoted to a general 

 account of the nature of vitamins, with a history of 

 their discovery. It is pointed out that we do not 

 know how they act. In many ways they behave like 

 catalysts ; in other ways, they seem more related to 

 the chemical messengers or hormones. McCollum 

 directs attention to the fact that they do not behave 

 as hormones in the sense of being produced in one 

 organ for the purpose of bringing about reactions in 

 other places. They are not formed by the animal 

 organism at all, so far as we know. 



A useful account of experimental methods is given 

 in the second chapter. It is to be feared that in- 

 attention to freedom from traces of vitamins in the 

 control diet has been the source of erroneous state- 

 ments. As to their chemical nature, we have still 



NO. 2816, VOL. I I 2] 



practically everything to learn. Like enzymes and 

 hormones, they are so extremely powerful that we 

 can remove more and more unessential impurities 

 from them, without affecting their activity. Thus 

 we finally arrive at a trace of a substance which has 

 very few chemical properties of any kind. Some 

 method by which these substances can be readily 

 separated from large quantities of the materials con- 

 taining them has yet to be worked out. Possibly it 

 may be found in an application of the adsorption 

 method used with success by Willstatter in the case 

 of enzymes. 



The making of concentrated preparations is described, 

 but it is to be regretted that the extravagant cost of 

 commercial products in relation to their actual content 

 in vitamins is not more insisted upon. As Drummond 

 has well pointed out, eggs and oranges are equally 

 useful at less than a fiftieth of the cost. If a reason- 

 ably varied diet with fresh fruit and vegetables be 

 taken, there is no need to worry about vitamins. 

 It is curious that so many people fail to realise that 

 vitamins are not drugs, to be taken under medical 

 direction, but natural constituents of food. It does 

 not matter how much of them be taken, provided that 

 it is enough. 



Detailed discussion is given of the various disorders 

 associated with deficiency of vitamins. It is here 

 that the question as to whether there are more than 

 the three (A, B, and C) vitamins comes into prominence. 

 Three chapters are devoted to practical problems of 

 appropriate diets for infants and adults, and a final 

 chapter on the interesting question of the vitamin 

 requirements of fungi, moulds, and bacteria is added. 

 An appendix gives tables of the distribution of the 

 vitamins in various articles of diet. It is a remarkable 

 fact that although some animal products are rich 

 in certain vitamins, the ultimate source of these appears 

 to be in all cases the vegetable kingdom. 



The book may be highly recommended. The work 

 of so many different investigators is given that the 

 reader is at times rather bewildered, and a summary 

 of the established data, given at the end of each 

 chapter, would be a welcome addition. There is, 

 however, an excellent index. W, M. Bavliss. 



The Atom of To-day. 



The Structure of the Atom. By Prof. E, N. da C. 

 Andrade. Pp. xv-i-314. (London: G. Bell and 

 Sons, Ltd., 1923.) \6s. net. 



TO give a comprehensive critical survey of the 

 prevailing theories of atornic structure and to 

 indicate their triumphs and inadctjuacies in a volume of 

 reasonable size is the professed object of the book under 



Q2 



