On the Chemical Properties of Soils. 7 



3. The surface and subsoil of a heavy clay field, con- 



taining scarcely any sand. 



4. A sterile sandy soil, containing much organic matter, 



and scarcely any lime. 



5. Pasture land, being a vegetable mould containing abun- 



dance of organic matter and a fair proportion of sand 

 and clay. 



These soils were preferred to others for experimental purposes 

 on account of their widely differing physical and chemical pro- 

 perties. They afford good examples of some of the more fre- 

 quent and important varieties of British soils. 



First Experiment, on Calcareous Clay. 



The soil used in the first experiment contained, in 100 

 parts : 



Moisture 1'51 



Organic matter and water of combination 11*08 



Oxides of iron and alumina 14-25 



Carbonate of lime .. .. 10-82 



Sulphate of lime *71 



Magnesia '51 



Potash (in acid solution) , .. .. '32 



Soda (in acid solution) '05 



Phosphoric acid *10 



Insoluble silicates and sand (chiefly clay) 60*65 



100*00 



Submitted to a mechanical analysis it yielded : 



Moisture 1*51 



Organic matter and water of combination ll'OS 



Carbonate of lime 10*82 



Clay 52-06 



Sand 24-53 



100-00 



3000 grains of this soil were shaken up in a glass-stoppered 

 bottle with 14,000 grains of ammonia solution, containing 

 23*24 grains of caustic ammonia in the imperial gallon. In the 

 course of the day the bottle was repeatedly shaken, and the liquid 

 then left to subside. After standing for three days the soil had 

 all settled to the bottom, and the greater part of the liquid could 

 be drawn off in a perfectly clear condition. This liquid was 

 slightly tinged with yellow. 



2000 grains of this clear liquid were then carefully neutralised 



