316 EXPEEIMENT STATION EECORD. 



so large au extent upou studies of soils in their natural condition and in which 

 cultural adaptations have not been obscured by long years of artificial treat- 

 ment. In the author's opinion the advance of knowledge of soils has been 

 retarded by the fact that investigations in this field have dealt mainly with 

 more or less artificial soils — that is, soils which have long been under cultiva- 

 tion and whose natural relations to vegetation have thus been obscured. 



The book " includes the discussion both of the methods and results of direct 

 physical, chemical, and botanical soil investigation, as well as the subject-mat- 

 ter relating to the origin, formation, classification, and physical as well as 

 chemical nature of soil, usually included in works on scientific agriculture. 



" In the presentation of these subjects, it has been the writer's aim to reach 

 both the students in his own classes and in the agricultural colleges generally, 

 as well as the fast increasing class of farmers of both regions who ai'e willing 

 and even anxious to avail themselves of the results and principles of scien- 

 tific investigation, without ' shying off ' from the new or unfamiliar words nec- 

 essary to embody new ideas. . . . But in order to segregate to some extent the 

 generally intelligible matter from that which requires more scientific prepara- 

 tion than can now be generally expected, it has been thought best to use in 

 the text two kinds of type ; the larger one embodying the matter presumed to 

 be interesting and intelligible to the general reader, while the smaller type 

 carries the illustrative detail and discussion which will be sought chiefly by 

 the student. 



" As regards the chemical nomenclature used in this volume, the writer has 

 not thought it advisable to follow the example set by some late authors in 

 substituting for the well-known names of the bases and acids, those of the 

 elements, and still less, those of the intangible ions. . . . 



" Inasmuch as all the elements are presented to and contained in the plant 

 in compounds only, and these compounds are themselves, in the dilute solu- 

 tions used by plants, known to be largely dissociated into their basic and acid 

 groups, it seems to be most natural to pi'esent them under the corresponding, 

 even if not absolutely theoretically coi'rect names of acids and bases, to which 

 the farmer and the trade have been accustomed for half a century. Upon these 

 considerations the long-used designations of potash, soda, lime, phosphoric, 

 sulphuric, nitric, and other acids and bases have been retained in this volume, 

 adding the chemical formula where, as in analytical statements, a doubt as to 

 their meaning might arise." 



The make-up of the book is indicated by the following summary of its con- 

 tents : An introduction and 5 chapters devoted to origin and formation of soils, 

 12 chapters to physics of soils, 6 chapters to chemistry of soils, and 3 chapters 

 to soils and native vegetation. 



The soil and its cultivation, P. Diffloth (Le sol ct les hihours. Paris: 

 J. B. BailUere tC Son, 1906, pp. ^90, flgs. lU; rev. in Mois ScL, 8 {1906), 

 No. Jf, p. 15; Nature [London'], 7^ {1906), No. 1905, p. -)). — This is one of the 

 series of volumes constituting the Eiicyclopedie af/ricole. edited by G. Wery. 



The volume treats of the origin, properties, composition, analysis, and cul- 

 tivation of soils, and is divided into two main parts, agrology and preparation 

 of the soil. Under the general head of agrology are discussed the relation 

 of land to agriculture and the general rules and principles which govern 

 the relations between the nature of the soil and the products which It yields. 

 The second part treats of the various operations of clearing, cultivating, and 

 improving land. The soil is considered in its threefold relation of mechanical 

 f'.upport, reserve material, and medium, niid recent discoveries regarding the 

 relation of the soil to the nutrition of plants are embodied in the work. 



