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Monsieur Bertrand, who has paid particular attention to thissubject, and made many ingenious experiments, observes, thatpetrifying springs have been found unfavourable for wateringpasture and meadow grounds. He ascertained and assigns thereasons of this : the calcareous matter they hold in solution, oc-casions a partial or total petrifaction of the grasses which growon the surface of such lands. The growth of these grasses isthereby checked, and they become unfit for the food of cattle.
But though waters of that description be unfit for such lands,they are peculiarly adapted to mossy soils, and waste lands ofevery kind. The calcareous matter they deposit, must not onlyconsolidate, but operate as a powerful stimulating manure to suchsterile wastes; and if the springs be powerful, a vast extent ofsuch soils may be reclaimed by them in a very short time. Sucha river as Vchno, (see Dr Rennie’s Second Essay), might in afew years convert the most sterile moss or moor into a solid fer-tile soil.
Rivers, too, which run through, or near large and populouscities in their course, must be peculiarly adapted for the purposeof flooding moss or any’ waste land. The alkaline and animalmatter, and saline substances, washed down by’ the common sew-ers, must render, the waters of such rivers fertilizing to a highdegree : it is certain, that more liquid manure has been washedaway into the ocean, by the Forth and Clyde, the Lilly and theThames , than would have reclaimed half of the waste lands ofthe empire, ifit had been practicable to overflow them with thoserivers. The rich meadows along the banks of the Thames belowLondon , and in similar situations, have been reclaimed by theoverflowings of rivers, enriched by' these means.
Section V.
We have it often in our power to improve the Quality of Waterfor the purpose of Flooding Waste ljxnd.
The manner in which this may be done is obvious: and inmany situations it is attended with so little labour and expense,that it may be accomplished with expedition and ease. As theadventitious matter which forms the mud of most rivers, operatespowerfully in reclaiming w’aste land, we have it frequently in ourpower to increase the quantity of that matter, and rendgr jhewaters more fertilizing.
First, With this view we ought first to examine the channelof any river before it be used for this purpose. If in any part cfits course, above the level of the land intended to be flooded, abed of sand, or gravel, or clay, or alluvial earth, be discovered,it is often easy, by altering the course of the river, or throwingin a quantity of these materials, to, wash them down by the riverin the time of a flood. By this means, they may be conveyed