INORGANIC COMPOSITION OF SOME AMERICAN SOILS. 9 



markably uniform in amount. This represents the solubility of 

 calcium oxalate in aqueous ammoniacal solutions of sodium and 

 ammonium chlorides, together with that dissolving during washing. 

 It appears to be independent of the amounts of calcium and magne- 

 sium present. In this work the amount of calcium oxide separated 

 from the precipitated magnesium was almost uniformly 0.7 milli- 

 gram, for the first 18 soils. This correction was applied in the last 8 

 analyses, instead of making the separations. 



The amount of manganese in the magnesium precipitate was so 

 small that no correction was made for this impurity. 



All calculations except water (H 2 0) at 110° are based on the weight 

 of the soil dried at 110° C. 



DESCRIPTION OF THE SAMPLES. 



(1) Norfolk sandy loam, 3 miles southwest of Laurinburg, N. C. 

 Depth to 14 inches. This type is formed from the outwash of the 

 more resistant soil particles of the higher formations farther inland. 

 It is a light yellowish sandy loam of the Coastal Plain province, and 

 generally considered productive. This particular sample was taken 

 from virgin soil covered with longleaf pine, white oak, hickory, and 

 occasional dogwood trees. No stones larger than J inch were found. 



(2) Norfolk sandy loam, subsoil of No. 1, depth 14 to 36 inches. 

 No stones larger than J inch in diameter were found. 



(3) Decatur clay loam, 1 mile east of Hollywood, Ala. Depth 

 to 4 inches. This soil is derived from the decomposition of lime- 

 stone and Knox dolomite. It belongs to the Limestone Valley and 

 Uplands province. It is of a dull-red color and considered fertile. 

 The sample was taken from an uncultivated spot forested with 

 shortleaf pine, hickory, white and red oak, persimmon, and shrubs 

 of different species and native grasses. No stones larger than £ inch 

 were found. 



(4) Decatur clay loam, subsoil of No. 3, depth 4 to 15 inches. 

 No stones larger than J inch in diameter were found. 



(5) Hagerstown loam, 1 mile northwest of Conshohocken, Pa. 

 Depth to 8 inches. This type is derived from the weathering of 

 limestone and belongs to the Limestone Valley and Upland province. 

 The sands are rich in mineral species. It is one of the best general 

 farming types in the eastern States. The sample was taken from a 

 potato field. The texture was that of a mellow brown silty loam. 

 This sample contained 1.8 per cent stones. Of this amount 92.4 

 per cent was quartz, 5.6 per cent limonite, and 1.8 per cent mica 

 schist. 



(6) Hagerstown loam, subsoil of No. 5, depth 8 to 24 inches. 

 This sample contained 5.1 per cent of stones. Of this 90.0 per cent 

 was quartz and 9.1 per cent mica schist. 



46688°— 14 2 



