714 EXPERIMENT STATION RECORD. 



I)roiiched, there being as mucli as 4 per cent of this constituent in the soil of 

 the lower parts of the Delta. 



In general it may be said that the soils of Egypt contain much silica, alumina, 

 and oxid of iron, less lime, small quantities of phosphoric acid, and a small 

 content of organic matter, never exceeding 4 to 9 per cent. 



Studies of the subterranean waters of the Nile Valley show that these are 

 controlled to a large extent by the flood stage of the Nile and to a less extent 

 by the number and location of the irrigation canals. The underground waters 

 vary widely in chemical composition, and observations of experimental wells 

 show that the Vvater infiltrating into the subsoil is much richer in soluble con- 

 stituents than the Nile water, there being considerable increases, ])articularly 

 in carbonates, calcium and magnesium sulphates, and sodium ehloi-id. 



The specific heat of certain soils, principally Russian, A. N. Sabanin 

 (Pochvovyedyenie [Pedologies, 10 (1908), A'o. ^, pp. 287-291). — From examina- 

 tions of 21 soils representing a variety of types the following conclusions were 

 drawn : There were very sharp fluctuations in the thermic capacity of the dif- 

 ferent soils and the calculated and observed capacities did not coincide in a 

 majority of cases. This thermic capacity was determined chiefly by the relative 

 proi)ortions of sand, clay, and humus in soils dried at 105° C, and also by the 

 proportion of water in air dried soils. The thermic capacity diminished from 

 the surface layer downward. 



Factors which determine fertility in soils, E. J. Russell {Sci. Prog. Twen- 

 tieth Cent., .'/ {1910), Xo. 15, pp. 353-365, pi. 1, figs. 3).— This article is based 

 upon the author's studies of the chemical and biological changes which take 

 place in the organic matter of soils under varying conditions (E. S. R., 22, p. 

 121). In these investigations a qhange was induced in the micro-organic flora 

 of the soil, usually by partial sterilization with toluene or by heat, and the 

 .altex-ation in the flora and the change in the course of the soil decomposition 

 were observed and as far as possible correlated. 



A short bibliography of the subject is given. 



Do soils wear out? {Amer. Agr., 85 (1910), No. 9, pp. 296-298, 306, 307, figs. 

 2). — This is a collection of short articles on What the Past Teaches, by M. 

 Whitney; Soils are Sick, by H. Hayward; Humus and Lime will Help, by T. Ij. 

 Lyon; Soils May Be Improved, by M. F. Miller; Soils Improve or Go Back, by 

 T. F. Hunt; Soils Respond to Good Tre.'itment, by B. W. Kilgore; and Farming 

 Methods at Fault, by A. M. Soule. 



In a general way these articles answer the question of the title in the nega- 

 tive. They show, however, how soils decline in i)roductiveness under bad treat- 

 ment, and as a rule improve imder good treatment. A realization of this in 

 the United States is leading to the replacement of the old exhaustive methods 

 of culture by better systems of cropping, manuring, and tillage, resulting in 

 increasing yields. 



Soil improvement experiments on lig'ht moor and sandy soils, Schulze- 

 DiEKHOFF (Dent. Landw. Presse, 37 {1910), Ao. S, pp. 87/, 85, figs. 2).— The 

 marked improvement of such soils by the use of Thomas slag and kainit is 

 reported. 



Potash and the mobilization of organic nitrogen in humus soils, P. Re- 

 nault {Engrais, 25 {1910), No. 5, pp. 132-135). — This article states that 

 acidity is not always the cause of the low nitrifying power of peat soils. Ex- 

 periments by Dumont are referred to as showing that slow nitrification is fre- 

 quently due not to lack of lime but to the form of the organic matter, and that 

 slow ammonification and subsequent nitrification is always accompanied by a 

 low percentage of potash. Dumont's experiments showed that carbonate of 

 potash directly favors nitrification and that the application of sulphate and 



