Action on soil's texture 455
Lime renders light soils more cohesive 457
II. Chemical action of lime 457
III. Biological action of lime 459
Action of lime on nitrogenous organic matter 460
Recapitulation 461

CHAPTER XXI.--INDIRECT MANURES--GYPSUM, SALT, ETC.

Gypsum 462
Mode in which gypsum acts 462
Salt 465
Antiquity of the use of salt 465
Nature of its action 465
Salt not a necessary plant-food 466
Can soda replace potash? 466
Salt of universal occurrence 467
Special sources of salt 468
The action of salt 468
Mechanical action on soils 470
Solvent action 470
Best used in small quantities along with manures 472
Affects quality of crop 472
Rate of application 473

CHAPTER XXII.--THE APPLICATION OF MANURES.

Influence of manures in increasing soil-fertility 474
Influence of farmyard manure on the soil 475
Farmyard manure _v._ artificials 476
Farmyard manure not favourable to certain crops 477
Conditions determining the application of artificial manures 477
Nature of the manure 478
Nitrogenous manures 478
Phosphatic manures 480
Potash manures 480
Nature of soil 481
Nature of previous manuring