Recent Agriculhiral Pidtlicaiions. 
405 
Part II. — Soils. 
1. Origin of Soils. — Effect of frost, oxygen, and carbonic acid in 
the decomposition of rocks. 
2. Physical Properties of Soils. — Absorption of moisture by the 
different ingredients of soils. Classification of soils. Influence of 
subsoil. Operations for improving soils. 
3. Chemical Analysis of Soils. — Determination of percentages 
of nitrogen, nitric acid, ammonia, carbon in organic compounds, 
phosphoric acid, potash. 
4. Chemical Constitution. — Nitrogen and carbon in the organic 
matter of soils. Abundance of in.soluble nitrogenous organic matter 
in soils. Oxidation of organic matter. Formation of nitrates in 
soils. Nitrification due to the activity of ferments. Circumstances 
controlling nitrification. Phosphoric acid. Potash. Lime. Silica. 
Oxide of iron. 
5. Absorbent properties of Soils. — Absorption of ammonia, potash, 
soda, carbonates, sulphates. Non-retention of nitrates. Composition 
of soil-water. Composition of drainage waters — from bare soils, and 
from cropped soils, manured and unmanured. Residues of manures. 
6. Sterility. — Arising from bad physical constitution of the soil, 
or from the presence of injurious matters — sulphate of iron, salt. 
Arising from bad cultivation and neglect of manuring. 
Part III.— Manures and Manuring. 
1. Liming and Marling. — Effect of lime upon the physical con- 
dition of soils, and upon the nitrogenous and other ingredients of 
manures. 
2. Plastering. — The use of gypsum, or sulphate of lime, and its 
effects upon manorial ingredients in the soil. 
3. Bare Fallowing. — Facilitates the working of the land, permits 
the destruction of weeds, and affects the richness of the soil. 
4. Irrigation. — Quantities of water employed. Methods of dis- 
tribution. 
5. Vegetable Manures. — Residues of crops. Plants cultivated as 
manures. Marine plants employed as manures. Oil cakes. Factory 
and other refuse. 
6. Manures of Animal Origin. — Guano and its adulterations. 
Phosphatic guanos. Fish manure. Dried blood. Wool and leather 
waste. 
7. Seicage and allied Manures. — Poudrette. Sewage farms. 
8. Nitrogenous Manures. — Sulphate of ammonia. Nitrate of 
soda : its loss in drainage waters. Comparative values of ammoniacal 
nitrogen and nitric nitrogen. 
9. Farmyard Manure. — Ingredients which give to farmyard 
manure its value. Fermentation, and origin of the ferments. 
Composition of interstitial air of farmyard manure. Losses of 
nitrogen, in the free state and as ammonia. Changes which dung 
undergoes in the soil. Duration of effect. Composts. 
