238 



ON THE CHEMICAL CONSTITUENTS OF SOILS. 



An aqueous infusion of the soil contained gypsum, 

 common salt, magnesia, and humus. 100 parts of 

 the soil gave : — 



Silica . . , 



Alumina 



Protx>xide and peroxide of iron 



Peroxide of manganese 



Lime .... 



Magnesia 



Potash, in combination with silica 



Soda, idem (principally) . 



Phosphoric acid, in combination with lime 



Sulphuric acid, idem 



Chlorine (in common salt) 



Humus, soluble in alkalies 



Humus .... 



Nitrogenous matter 



89-175 

 2-652 

 3-136 

 0-320 

 1-200 

 1-040 

 0-075 

 0-354 

 0-377 

 0081 

 0066 

 0-920 

 0-456 

 0-208 



100-000 



34. Surface-soil of a very fertile field in the prov- 

 ince of Dobrawitz and Lautschin. 100 parts of the 

 earth consisted of: — 



Siliceous sand, with a little magnetic iron sand . 43-780 

 Finer part separated by the sieve . . 56-220 



100-000 



100 parts yielded to water 0*175 part of salts, 

 consisting of common salt, gypsum, magnesia, and 

 humic acid. 100 parts, by weight, of the earth con- 

 sisted of: — 



Silica . . . . . 



Alumina .... 



Protoxide and peroxide of iron 



Peroxide of manganese . 



Lime . . . . . 



Magnesia .... 



Potash, in combination with silica 



Soda, idem, .... 



Phosphoric acid, in combination with lime 



Sulphuric acid, idem 



Chlorine (in common salt) 



Humus, soluble in alkalies 



Humus . . . . . 



Nitrogenous matter 



. 89.634 



3224 

 . 2-944 



1-160 

 . 0-349 



0-300 

 . 0-160 



0-428 

 . 0-246 



0-005 

 . 0-012 



0-750 

 . 0-340 



0-448 



100-000 



35. Analysis of a soil formed by the disintegration 

 of basalt. 100 parts of the earth consisted of: — 



