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sterility. In this island, our commercial system at 
present has the effect of affording substances, which 
in their use and decomposition must enrich the 
land. Corn, sugar, tallow, oil, skins, furs, wine, 
silk, cotton, &c. are imported, and fish are supplied 
from the sea. Amongst our numerous exports, 
woollen, and linen, and leather goods are almost 
the only substances which contain any nutritive 
materials derived from the soil. 
In all courses of crops it is necessary that every 
part of the soil should be made as useful as possible 
to the different plants ; but the depth of the fur- 
row in ploughing must depend upon the nature of 
the soil, and of the subsoil. In rich clayey soils 
the furrow can scarcely be too deep ; and even in 
sands, unless the subsoil contains some principles 
noxious to vegetables, the same practice should be 
adopted. When the roots are deep, they are less 
liable to be injured, either by excess of rain, or 
drought ; the layers shoot forth their radicles into 
every part of the soil ; and the space from which 
the nourishment is derived is more considerable, 
than when the seed is superficially inserted in the 
soil. 
There has been much difference of opinion with 
respect to permanent pasture ; but the advantages 
or disadvantages can only be reasoned upon accord- 
ing to the circumstances of situation and climate. 
Under the circumstances of irrigation, lands are 
extremely productive, with comparatively little 
labour ; and in climates where great quantities of 
rain fall, the natural irrigation produces the same 
effects as artificial. When hay is in great demand. 
