March 25, 1920] 



NATURE 



99 



Science of Food. 



(1) Bacteriology and Mycology of Foods. By Dr. 

 Fred Wilbur Tanner. Pp. vi + 592+io plates. 

 (New York : John Wiley and Sons, Inc. ; Lon- 

 don : Chapman and Hall, Ltd., 1919.) Price 

 28a-. net. 



(2) Food: Its Composition and Preparation. A 

 Text-hook for Classes in Household Sci-etice. By 

 Mary T. Dowd and Jean D. Jame^n. (The 

 Wiley Technical Series.) Pp. viii+173. (New 

 York : John Wiley and Sons, Inc. ; London : 

 Chapman and Hall, Ltd., 1918.) Price 65. net. 



THESE two books are very laudable attempts 

 by our American cousins to place the im- 

 portant question of food on a scientific basis. The 

 war brought home to people at larg^e the im- 

 portance of such study, but one hopes, in days of 

 peace, not only that investigations will continue, 

 but also that their application will be carried out 

 to a greater extent. 



(i) The first of the two books mentioned 

 above is very complete, not only in the 

 number of important foods dealt with, but 

 also in the numerous methods of investigation 

 described to detect impurities and prevent 

 contamination with undesirable admixtures. It 

 is the science of cleanliness in technical costume. 

 The preface informs us that the work is written 

 for those who wish to fit themselves for food 

 control ; but as it presupposes a thorough training 

 in bacteriology and chemistry, we fear it will 

 scarcely appeal to those who are food controllers 

 here. What is really wanted is a book that he 

 who runs may read, a book intelligible to the 

 manufacturer, the packer, the tradesman, and the 

 housewife. To present such with the graphic 

 formulae of, say, amino-acids and fats would be 

 simply to terrify them. Still, the book should be 

 useful to a more limited section of the population 



namely, the analysts and bacteriologists. Its 

 price strikes one as exorbitant even in these days 

 of high charg-es. 



(2) The second book is of a much more practical 

 nature, and will be welcomed by all those engaged 

 in the study of household science. It is an excel- 

 lent chemical introduction to the science of intelli- 

 j^^ent cookery. The authors have taken care 

 to provide themselves with a good preliminary 

 knowledge of physiology and bio-chemistry, and 

 if they go a little wrong in a few details, such as 

 in their account of the vitamines, the slips are 

 trivial, and do not affect their main arguments or 

 their main endeavour, which is to rescue cookery 

 from the domain of empiricism and ignorance. 



W. D. H. 

 NO. 2630, VOL. 105] 



Our Bookshelf. 



Petrology for Students: An Introduction to the 

 Study of Rocks under the Microscope. By Dr, 

 Alfred Harker. Fifth edition, revised. (Cam- 

 bridge Geological Series.) Pp. viii + 300, 

 (Cambridge : At the University Press, 1919.) 

 Price 8s. 6d. net. 

 A HEARTY welcome must be extended to this new 

 edition of one of our most widely known geo- 

 logical text-books, which has had considerable 

 influence in securing systematic and accurate 

 descriptions of rocks by British petrologists. The 

 present edition contains a few pages less than 

 the previous issue, but this has been accomplished 

 by diminishing the space at the headings of 

 chapters and by the excision of superfluous notes 

 and references to occurrences of minor interest, so 

 that the value of the book is in no way diminished. 

 New illustrations have been added, and the 

 chapters on metamorphism largely re-written. 



As in previous editions, the author rejects names 

 given unnecessarily to local varieties, which 

 he distinguishes simply by reference to the places- 

 from which the names were formed. This process- 

 might with advantage have been carried very 

 much further. There is, however, already so- 

 much diversity in petrological nomenclature, not 

 only in different countries, but also among 

 individual geologists, that the author is probably 

 wise in refraining from attempting any far- 

 reaching reforms. 



Perhaps in another edition a certain number of 

 analyses of the more important rock-species might 

 be included, as well as their specific gravities,, 

 which afford a valuable means of checking the 

 determination of rocks in the field. J. W. E. 



Chemistry and its Mysteries : The Story of What 

 Things are Made Of, Told in Simple Language. 

 By Charles R. Gibson. (Science for Children.) 

 Pp. 246. (London : Seeley, Service, and Co., 

 Ltd., 1920.) Price ^s. 6d. net. 

 Here is another of Mr. Gibson's wonderful books 

 for children. This time Mr, Gibson treats of the 

 elements of chemistry, the conception of chemical 

 constitution, combustion and respiration, electro- 

 lysis, spectroscopy, and "queer things" such as 

 radium and liquid air. The author has not lost 

 his powers of stating scientific propositions in 

 simple and attractive form without departing 

 (except in quite minor details) from the strictest 

 accuracy. We confess that we had thought 

 modern children rather more sophisticated and apt 

 to regard as ridiculous analogies drawn from 

 nursery games ; but in this matter we bow to 

 Mr. Gibson's judgment. His success in what he 

 has set himself to do is beyond question ; 

 criticism, if any were offered, would concern 

 rather his objects. But this is not the place to 

 inquire whether it is really useful, or even harm- 

 less, to present the complex and highly theoretical 

 conclusions of modern science without any serious^ 

 attempt to present also the evidence on which 

 they are based. 



