ey be fed? not on water alone; the consequence of such a
supposition would lead us to absurdity; nor can they be fed on any
other element without the dissolution of land. According to my views of
things, it is certain that those animals are ultimately fed on vegetable
bodies; and it is equally certain, that plants require a soil on which
they may not only fix their fibrous roots, but find their nourishment
at least in part; for, that air, water, and the matter of light, also
contribute, cannot be doubted. But if animals, which are to form the
strata of the earth, are to be fed on plants, and these are to be
nourished by the matter of this earth, the waste of vegetable matter
upon the surface of the earth must be repaired; the exhausted soil must
be transported from the surface of the land; and fertility must be
restored by the gradual decay of solid parts, and by the successive
removal of soil from stage to stage. What a reverie, therefore, is that
idea, of bringing the earth to perfection by fixing the state of its
vegetable surface!

The description of those natural operations, which M. de Luc has given
with a view to establish the duration of the mountains, is founded upon
nothing but their destruction. These beds of rivers, which, according
to our author, are _hardly_ to be wasted any more, will not satisfy a
philosopher, who requires to see no degree of wasting in a body which is
to remain for ever, or continue without change. But, however untenable
this supposition of a fixed state in the surface of this earth, the
accuracy of the natural philosopher may still be observed in the
absurdity of the proposition. "L'etat des _montagnes_ sera _fixe_,
partout ou les _rivieres_ seront arrivees au point de n'emporter pas
plus de limon hors de leur enceinte, que l'air et les pluies n'y
deposeront de _terre vegetable_, et voila enfin quel sera le repos,
l'etat permanent de la surface de notre globe. Car alors il y aura
compensation entre les destructions et les reparations simultanees, et
les montagnes surement ne s'abaisseront plus."

Surely, if there is in the system of nature wisdom, we may look for
compensation between the destroying and repairing operations of the
globe. But why seek for this compensation in the _rest_ or immobility of
things? Why suppose perfection in the want of change? The summit of the
Alps was once the bottom of the sea; the existence of our land depended
then upon the change of seas and continent