C 22 -j 



their texture, and causes them to be less permeable 

 to water. 



The instances in which it must be obviously pre- 

 judicial, are those of sandy dry siliceous soils, contain- 

 ing little animal or vegetable matter, flere it can 

 only be destructive, for it decomposes that on which 

 the soil depends for its productiveness. 



The advantages of irrigation, though so lately a 

 subject of much attention, were well known to the 

 ancients ; and more than two centuries ago the prac- 

 tice was recommended to the farmers of our country 

 by Lord Bacon ; ** meadow-watering/' according to 

 the statements of this illustrious personage, (given in 

 his Natural History, in the article Vegetation,) acts 

 not only by supplying useful moisture to the grass ; 

 but likewise the water carries nourishment dissolved 

 in it, and defends the roots from the effects of cold. 



No general principles can be laid down respecting 

 the comparative merit of the different systems of culti- 

 vation, and the different systems of crops adopted in 

 different districts, unless the chemical nature of the 

 soil, and the physical circumstances to which it is ex- 

 posed are fully known. Stiff coherent soils are those 

 most benefited by minute division and aeration, and in 

 the drill system of husbandry, these effects are pro- 

 duced to the greatest extent ; but still the labour and 

 expense connected with its application in certain dis- 

 tricts, may not be compensated for by the advantages 

 produced. Moist climates are best fitted for raising 

 the artificial grasses, oats, and broad leaved crops ; 

 stiff aluminous soils, in general, are most adapted for 



