102 SOILS: PROPERTIES AND MANAGEMENT 



silts, and clays than the representatives of the other 

 soil provinces; this is true also of the glacial soils, but 

 to a less degree. Under such conditions of weathering 

 the sands have not as yet been depleted of their stores 

 of essential elements. Average data compiled from a 

 number of soil analyses by Hall, 1 presented below, tend 

 to corroborate the data already noted and that obtained 

 by Loughridge 2 of California : 



COMPOSITION OF SOIL SEPARATES 



76. Value of a mechanical analysis. It is now evi- 

 dent that the proper interpretation of a mechanical 

 analysis throws considerable light on the probable physical 

 and chemical properties of a soil. To the trained ob- 

 server the preponderance of sand or clay signifies certain 

 physical properties which may affect the plant not only 

 mechanically, but physiologically as well, through varia- 



1 Hall, A. D., and Russell, E. J. Soil Surveys and Soil 

 Analyses. Jour. Agr. Science, Vol. IV, Part 2, p. 199. 1911. 

 Also a Report of the Agriculture and Soils of Kent, Surrey, and 

 Sussex. Board of Agriculture and Fisheries. 1911. 



2 Loughridge, R. H. On the Distribution of Soil Ingredi- 

 ents among Sediments Obtained in Silt Analyses. Amer. 

 Jour. Sci., Vol. VII, p. 17. 1874. 



In this connection see also Puchner, Dr. Uber die Ver- 

 tielung von Nahrstoffen in den Verschieden Feinen Bestandteilen 

 des Boden. Landw. Ver. Stat., Band 66, Seite 463-470. 1907. 



