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changes which are requisite to render it fertile, be expedited inthe same way i And is it not highly probable that this is anotherway in which water has operated on mossy and moorish soils, bythe natural operations we see going on along the banks of riversand rivulets ?
Fifthly, Moisture greatly promotes the fermentation of vegetablematter. Or rather it is absolutely requisite in this process. Forwithout it, that is, when vegetable matter is entirely dry, thisprocess cannot commence, far less be completed. Whereas whena sufficient quantity of water is applied, fermentation speedily be-gins, and is carried on with rapidity. In some cases, it becomesso rapid that it cannot be distinguished from combustion. Indeedfermentation and combustion, are the same process. The formeris slow, the latter more rapid. Still they difter only' in degree,.not in kind.
And in some soils water alone is requisite to render the fermen-tation so rapid, that it cannot be distinguished from combustion.For instance, some mosses and other soils contain such a portionof pyrites, that when they are flooded, or exposed to alternatemoisture, and drought, they will become heated, and smoke, andsometimes even kindle into conflagration.
If this bo the case, flooding may have a similar effect, andoperate in the same way on such soils as paring and burning.
Sixthly, Flooding waste lands must on all the above accountsalter and improve their texture as a soil. The vegetable matterthey contain being disorganized, the whole soil must collapse andbe consolidated. Its particles being more reduced, must enterinto closer contact and more intimate combinations. In short,such a soil must differ as much from its original state, as wellmade dung differs in its texture from that which is full of strawand newly turned out from the stall. Even the mechanical pres-sure of a body of stagnant water, must tend partly to consolidatea soft mossy soil.
But perhaps the chief way in which flooding operates in re-claiming waste land, is,
' . Lastly, By the adventitious matter which is deposited by thismeans on the soil; more especially along the banks of consider-able rivers in time of floods. Particles of sand, clay, calcareousmatter, and saline substances, are carried along by the currentof rivers. Wherever they overflow their banks, this muddy waterbecomes stagnant; and thus depositing on the surface a rich com-post of alluvial soil, consisting of all kinds of earth over whichthe river runs in its. course, it must form a soil of all others themost fertile. Combining with the original surface over which itis spread, and impregnated with saline substances of the richeststimulating qualities, it must alter the texture and the qualities(if such a soil, and improve it not for a time only, but for ever.Probably the greater part of readers will be disposed to ascribe