ON THE CHEMICAL CONSTITUENTS OF SOILS. 



245 



100-000 



This soil is improved by gypsum. Its sterility is 

 due to the excessive quantity of carbonate of soda 

 which is present. 



NORTH AMERICA. 



46. Surface-soil of alluvial land in Ohio, remark- 

 able for its great fertility. 100 parts consisted of: — 



Silica and fine siliceous sand 



Alumina ..... 



Peroxide and protoxide of iron (much magnetic 



iron sand) .... 



Peroxide of manganese 

 Lime .... 



Magnesia 



Potash, principally combined with silica 

 Soda .... 



Phosphoric acid, combined with lime and oxide of 



iron .... 



Sulphuric acid, combined with lime . 

 Chlorine 



Humus, soluble in alkalies 

 Nitrogenous organic matter 

 Wax and resinous matter 



79-538 

 7-306 



5-824 

 1-320 

 0-619 

 1024 

 0-200 

 0024 



1-776 

 0122 

 0036 

 1-950 

 0-236 

 0-025 



100000 



47. (A.) Surface-soil of a mountainous district in 

 the neighborhood of Ohio. (B.) analysis of the 

 subsoil. This soil is also distinguished for its great 

 fertility. 100 parts contain : — 



21* 



