CONTENTS. V 



PAGE 



CHAPTER VI. 



The soil, its formation and composition 77 



Varieties in the appearance and depth of soils in various parts 

 of Ireland — The subsoil — Agencies by which the hard rock is 

 converted into the arable soil — Vegetation of coral islands — 

 Origin of the organic matters contained in soils — Properties 

 of alumina-^Composition of clay — its influence on the fertility 

 of the soil — Importance to the farmer of the knowledge of the 

 composition of the rocks from which soils are derived — 

 Granite — its distribution in Ireland — composition of the 

 minerals which compose it — Deficient ingredients in granite 

 soils and influence of elevation on their fertility — Mica slate 

 — character of the soils derived from it — Clay slate — Variety 

 of agricultural character presented by the soils of this 

 formation — Sandstone and Greywacke soils — Limestone — 

 Magnesian limestone — Qualities of the soils in the centre of 

 Ireland — Trap rocks — Wliite limestone of Antrim — Organic 

 matter of the soil — Nature of peat — Erroneous opinions 

 respecting the influence of humus on vegetation — Physical 

 qualities of soils. 



CHAPTER VII. 



Effects produced on soils by the growth of plants, and 

 plans adopted for maintaining their fertility 95 



Origin of agriculture — effects of cultivation upon wild plants — 

 knowledge necessary to enable the farmer to improve the 

 quality of the soil — Nature of exhaustion — Kind and quantity 

 of inorganic matters contained in the crops cultivated in this 

 country — means adopted for maintaining the productiveness 

 of soils — Green crops — Circumstances which influence the 

 exhausting effects of plants — Rotation of crops — Practical 

 rules for the farmer — Influence of the soil upon the quality of 

 the crop. 



CHAPTER VIII. 



Means adopted for improving the soil, and maintaining 



its fertility by the application of manures 105 



Animal manures — Principles of manuring — Composition of 

 the liquid and solid excrements of man — their importance as 

 applications to the soil — Eflects of diet upon their fertilizing 

 qualities — Methotls of applying them adopted in various 

 countries — Poudrette — Urate — Plans proposed for the ap- 

 plication of sewage to agricultural purposes — Means by 

 which night soil and urine may be rendered inodorous- 

 Composition and agricultural value of the urine of the horse, 

 cow, and pig — Calculation of the loss experienced by the 

 farmer who neglects their preservation — Chemical composi- 

 tion and fertilizing qualities of the solid excrements of the 

 domestic animals — Difllrence in the value of the dung of 



