78 



NATURE AND PROPERTIES OF SOILS 



Table XIII 



CHEMICAL COMPOSITION OF VARIOUS SOIL SEPARATES 



richer in phosphoric acid, potash and lime than the coarser. 

 As would be expected the sands, silts, and clays of arid soils 

 show less difference than those of the other provinces. Under 

 arid conditions the sands have not as yet become depleted of 

 their store of essential elements. Average figures compiled 

 from Hall 's analyses x of soils from southeastern England cor- 

 roborate the data already noted. In addition, Hall shows that 

 the magnesia, iron, and alumina are higher in the finer sep- 

 arates while there is considerably more silica in the sand 

 groups. 2 



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

 Jour. Agr. Sci., 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. See also: Loughridge, R. H., On the Distribution 

 of Soil Ingredients among Sediments Obtained in Silt Analyses; Amer. 

 Jour. Sci., Vol. VII, p. 17, 1874. Puchner, H., fiber die Vertielung von 

 Nahrstoffen in den Verschieden Feinen Bestandteilen des Boden; Landw. 

 Ver. Stat., Band 66, Seite 463-470, 1907. Hendrick, J., and Ogg, W. J., 

 Studies of Scottish Drift Soil, Part I. The Composition of the Soil and 

 of the Mineral Particles Which Compose It; Jour. Agr. Sci., Vol. VII, 

 Part 4, pp. 458-469, Apr. 1916. McGeorge, W. T., Composition of Ha- 

 waiian Soil Particles; Haw. Agr. Exp. Sta., U. S. Dept. Agr., Bui. 42, 

 Jan., 1917. Robinson, G. W., Studies of the Pakezoic Soils of North 

 Wales; Jour. Agr. Res., Vol. VIII, Part 3, pp. 380-381, June, 1917. 



a McGeorge 's investigation of the residual volcanic soils of Hawaii 

 shows some noteworthy exceptions to the work of Pailyer and Hall in 



