On Flooding Land. 285 



any vegetable matter with which it comes in contact ; and 

 that the mechanical weight of a body of stagnant water, 

 must tend to consolidate, and to improve the texture of a 

 soft soil. But the salutary effects of flooding, may princi- 

 pally be ascribed to the advantages of moisture, so essential 

 for vegetation ; and to the particles of sand, clay, earth, cal- 

 careous matter, and other adventitious substances, with 

 which the waters are impregnated. In peat-bogs also, flood- 

 ing has a powerful effect, in decomposing and extracting the 

 antiseptic substances, or colouring matter contained in the 

 bog, and carrying them off. 



3. The Waters calculated for Flooding. All sorts of water 

 are not equally adapted for the beneficial practice of flood- 

 ing. Pure spring water, especially such as issues from cal- 

 careous strata, answers the purpose well ; and if it can be 

 used in sufficient quantities, will convert heath and coarse 

 herbage into sweet pasture grasses. Soft, and also muddy 

 water may be employed with advantage. River water is of- 

 ten impregnated with a number of useful ingredients ; and 

 the quality of water may sometimes be artificially improved, 

 by a mixture of calcareous and other substances. But 

 waters that issue from peat-mosses, or soils impregnated with 

 pyrites, or bituminous oil, are considered to be injurious. 



4. The Seasons fittest for the Operation. The object of 

 water meadows, is essentially different from that of impro- 

 ving waste lands by means of flooding. In the former case, 

 water is frequently made use of to nourish the grasses al- 

 ready produced by the soil. In the latter the purpose is, to 

 destroy the indigenous plants, as they are generally useless. 

 Hence, though covering the soil with water in winter, is of 

 use, yet the greatest improvement must be effected by summer 



flooding. The heat of the sun, combined with water, produces 

 a putrid fermentation of the vegetable matter on the surface 

 of the land ; after which, when the land is left dry, the coarse 

 and useless herbage disappears, and a rapid growth of suc- 

 culent grasses rises in its place. This is the result even on 

 sterile mosses. 



5. Advantages and Disadvantages of the process. The great 

 advantages of flooding are, the cheapness of the process, and 

 the facility with which it is executed. On the other hand, 

 it is only in very flat countries that it can be used to any 

 extent ; and if it be carried on upon a great scale, covering 

 great tracts of country with water, in cold, and still more in 

 the warm seasons of the year, must render the climate 

 moist and unwholesome ( 45<J ). At the same time, where the 



