BOOKS AND CURRENT LITERATURE 163 



The remaininji; chapters deal with the " hiws of environmental change," 

 the "laws of internal change," and the "continuous process of adjust- 

 ment." The book as a whole, especially the later chapters, is very 

 largely made up of lists of apparently well-chosen literature references. 

 This is a novel type of introductory scientific treatise, w^herein the 

 author himself says as little as possible and merely directs the student 

 to writings already published. It seems probable that this type of 

 introduction may prove more useful to the coming generation than 

 the prevailing authoritative elementary text-book, which presents its 

 science, not as it is, l^ut as the author conceives it to be, or even as he 

 thinks it ought to be, with few^ or no references to original sources. At 

 any rate, it is hard to think of Adams' little book as ever being "taught" 

 in the older way. Two verj^ full indexes (to names as well as subjects) 

 complete the volume. — B. E. L. 



Agricultural Chemistry. — Although chemistry is the foundation 

 on which modern agriculture has been erected, and the men most 

 notable in the development of agriculture have been predominantly 

 chemists, relatively few of the many books dealing wdth the chemistry 

 of agriculture have borne the title Agricultural Chemistry. The title 

 to Dr. Fraps' book^ therefore immediately arrests our attention. What 

 is agricultural chemistry? Naturally, the answer should be: the sci- 

 ence of chemistry applied to the art of agriculture. Practically, we 

 must look for the definition to the conception of the subject by the 

 authors of the few books that bear the name. If agricultural chemistry 

 w^ere to surrender to agronomy, dairying, animal nutrition, plant ph3^si- 

 ology, and similar departments, those portions of its subject matter to 

 which they also lay claim, there would remain but little. The author 

 of this volume agrees in the scope of his work fairly well with that of 

 Adolph Maj^er, though the treatment is much abridged. The first 

 and largest volume of Mayer's Agriculturchemie is essentially plant 

 physiology; the other three deal wdth soils, fertilizers, and fermentation. 

 Fraps gives much space to soil physics and chemistry, interspersed with 

 plant physiology; two chapters to manures and fertilization; and the 

 remainder of the book to the leading principles of animal nutrition, 

 including milk production. In common with Maj^er he has failed to 

 include the chemistry of dairying, — an omission to be regretted. 



1 Fraps, G. S. Principles of Agricultural Chemistry. Pp. 493, figs. 94. 

 Easton, Pa., The Chemical Publishing Company, 1913 ($4.00). 



