Oh the Chemical Properties of Soils. . 109 
romoved from a weak solution of caustic ammonia prepared 
with distilled water, and to compare the results with those ob- 
tained by other observers from similar experiments on other soils. 
The ammonia solution used in the subsequent experiments 
was of the same strength as that before used, and contained 
23"24 grains of ammonia (N U,) in the gallon, or '332 grains of 
ammonia in 1000 grains of liquid. 
The soils employed in these and all following experiments 
were : — 
1. A calcareous clay. 
2. A fertile loam, containing a little lime, mixed in equal 
proportion with the clay subsoil on which it rests. 
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 fof 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 'Tl 
Magnesia '51 
Potash (in acid solution) '32 
Soda (in acid solution) *05 
Phosphoric acid -lO 
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 11 "08 
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 
