SOILS — FERTILIZERS. 719 



considerable variations in sucli deterniiiiatlons. Tlie averages of 5 means of 

 5 samples each were fonnd to give results which could I)e relied upon. Varia- 

 tions due to applieations of potash and soda could not be accurately determined. 

 On the other hand, those due to ai)plications of lime and phosphoric acid were 

 readily detected. 



Soil testing. F. W. Taylor {Nctv Hampshire Sta. Ritts. 1907-S, pp. 311, 

 312). — Tests of the wire-basket method of the Bureau of Soils of this Depart- 

 ment are reported, the general conclusion being " that tlie method, while simple 

 and of com[taratively easy operation, fails to determine with any considerable 

 degree of accuracy the manurial reipiirements of our common types of soil. 

 It is probable, however, that with soils markedly deficient in humus or in one 

 or more particular elements, the method would have some valui' in making the 

 determination." 



How can the farmer maintain the fertility of the soil? C. (i. Hopkins 

 {Quart. Rpt. Kaits. lid. Agr., 2S (HWO), No. 109, pp. JJ--',6' ) .— The causes of a 

 decline of soil fertility are discussed and the use of rotations, manure, and 

 phosphates to restore i)roductiveness in soils of the corn belt is explained. The 

 basis of the system is an increase of hunniy and phosphates. 



Fertilizers and manures, A. L). Hall {London, 190!), pp. A'1'/+3S-J, pJs. 7). — 

 This book is meant to be a companion to the author's treatise on the soil (E. S. 

 K., 20, 1). 1113), and both are intended for the use of farmers and senior stu- 

 dents and teachers in English agricultural schools. The presentation of the 

 subject is as nontechnical as possible, but assumes some elementary knowledge 

 of chemistrv. 



The book contains a brief historical statement and very liicidiy i)resents the 

 argument for the use of fertilizers as well as the principles upon which the 

 modern theory of the use of fertilizers is based. 



In the author's opinion "the future . . . lies with intensive farming; every 

 year the ratio of the cultivable land to the population of the world shrinks ; 

 every year science puts fresh resources in the hands of the farmer. . . . Inten- 

 sive farming implies the use of fertilizers; still more it implies, or should imply, 

 skill and knowledge in using them." 



The results of the Rothamsted experiments have been freely drawn upon in 

 the preparation of the book, and, as the author states, much of the matter has 

 already been printed (E. S. E., 18, p. 921 ; 20, pp. 428, 1018). 



The book contains an introduction and chapters dealing with fertilizers con- 

 taining nitrogen, the function and comparative value of nitrogenous manures, 

 phosphatic manures, the function and use of phosphatic fertilizers, the potassic 

 fertilizers, farmyard manure, Peruvian guano and other mixed fertilizers, ma- 

 terials of indirect fertilizing value, theories of fertilizer action, systems of 

 manuring crops, the valuation and purchase of fertilizers, and the conducting 

 of experiments with fertilizers. 



Artificial manures, G. Ville, trans, and edited by W. Crookes, rev. by W. 

 ("rookks and .7. I'krcival (London, Xcw York, Bomhai/, and Calcutta, 1909, new 

 ed. rev., pp. XXXVIII+S-'iJ, pis. 6, figs. 10; rev. in Cliem. News, 100 (.1909), No. 

 2592, p. 59). — This is a new edition of this translation, containing nmch new 

 matter relating especially to substances which have recently come into promi- 

 nence as fertilizing agents, and adapting the fornuilas for fertilizers to modern 

 requirements and to the needs of the P^nglish farmer. 



Mineral fertilizers in 1908, L. Grandeau (Jour. Agr. Prat, n. ser., 18 (1909), 

 Nos. ^8, pp. 77, 7S; 29, pp. 107-109). — Statistics of the production and consump- 

 tion of fertilizers during 1908 are briefly reviewed. The production of raw 

 phosphate is given as about 5,000,000 tons. The larger part of this raw phos- 



