142 EUROPEAN AGRICULTURE. 



tions of his irrigated lands, which had even been drained, con 

 tinued to affect his sheep with the rot ; and this evil was not 

 remedied until the draining was carried to the depth of eight 

 feet or more. Before that, without doubt, the stagnant water at 

 the bottom prevented the water of irrigation from passing off, 

 and may be said to have poisoned the whole ground. 



In irrigation skilfully managed, the increase of product is 

 often very great twofold, fourfold, in many cases even five 

 fold. Even sands, which were barren, have, by irrigation, been 

 made productive. Plants, in such cases, having once found a 

 footing, by the spread and decay of their own roots, have at 

 length formed a soil, and created around themselves the elements 

 of fertility. The effect of pure water, I have already said, is 

 considerable ; but when this water brings with it the refuse of 

 the streets and habitations of a town, in a state of solution, the 

 effects, as we shall presently see, are most remarkable. I have 

 seen it stated, that water issuing from a limestone soil, and 

 strongly impregnated with lime in the form of a sulphate or 

 other combination, has been employed with great success in 

 irrigation. Such instances have not come under my observa 

 tion ; but I cannot doubt the effect, where the soil was of a 

 nature to require that element. In respect to manures, or any 

 of the constituents of plants, it is evident they can be taken up 

 only in a state of the finest solution. Here homoeopathy tri 

 umphs, and no human sense is acute enough to discern, no 

 human scales are fine enough to measure, those infinitesimal 

 atoms out of which the rough substance of the gnarled oak is 

 formed. 



It would be idle, in a work of this nature, to attempt to lay 

 down any thing more than the general principles of irrigation. 

 In the accomplishment of any particular work, all the localities 

 are to be considered, and the effecting it upon any large scale 

 would require considerable engineering skill. 



Irrigation of land and inundation are not the same. The in 

 undation of land resembles what I have already described under 

 the process of warping, where, the land being enclosed by em 

 bankments, the water is admitted to flood the land, and is held 

 fast until its floating riches are deposited. This can seldom be 

 done without disadvantage upon a growing crop, unless when in 

 its earliest stages of growth. Irrigation is the gradual filtering 



