ON THE CHEMICAL CONSTITUENTS OF SOILS. 



235 



100.000 



The specimen for analysis was taken at a depth 

 of 10 inches from the surface of a field, which had 

 been manured five years previously, and had pro- 

 duced since that time rape, rye, wheat, and beans. 

 The crops of all these were plentiful, and of excel- 

 lent quality. It is singular that this soil, which 

 contains such a small proportion of gypsum, should 

 be adapted for the cultivation of beans, and must 

 be ascribed to the depth of the surface-soil. Yet, 

 notwithstanding this, gypsum would form a beneficial 

 manure to the land. 



28. Analysis of very fertile alluvial* soil, from 



Honigpolder; no manure had ever been applied to 



it. 100 parts contain: — 



Siliceous sand separated by the sieve . . 4*5 



Earthy portion of the soil 



100 parts of the latter consisted of: — 



Silica, and fine siliceous sand 



Alumina .... 



Peroxide of iron .... 



Peroxide of manganese . . 



Lime . . • . . 



Magnesia .... 



Potash, principally in combination with silica 



Soda, idem . . . 



Phosphoric acid combined with lime . 



Sulphuric acid, idem 



Chlorine (in common salt) 



Carbonic acid, combined with lime 



Humus soluble in alkalies 



Humus .... 



Nitrogenous matter .... 



Water ..... 



95-5 

 1000 



64-800 

 5.700 

 6-100 

 0090 

 5-880 

 0-840 

 0-210 

 0393 

 0-430 

 0-210 

 0-201 

 3-920 

 2-540 

 5-600 

 1-582 

 1504 



100000 



