The Earth as Modified by Human Action | Page 8

ridges; the vegetable
earth accumulated beneath the trees by the decay of leaves and fallen
trunks, the soil of the alpine pastures which skirted and indented the
woods, and the mould of the upland fields, are washed away; meadows,
once fertilized by irrigation, are waste and unproductive because the
cisterns and reservoirs that supplied the ancient canals are broken, or
the springs that fed them dried up; rivers famous in history and song
have shrunk to humble brooklets; the willows that ornamented and
protected the banks of the lesser watercourses are gone, and the rivulets
have ceased to exist as perennial currents, because the little water that
finds its way into their old channels is evaporated by the droughts of
summer, or absorbed by the parched earth before it reaches the
lowlands; the beds of the brooks have widened into broad expanses of
pebbles and gravel, over which, though in the hot season passed
dryshod, in winter sealike torrents thunder; the entrances of navigable
streams are obstructed by sandbars; and harbors, once marts of an
extensive commerce, are shoaled by the deposits of the rivers at whose
mouths they lie; the elevation of the beds of estuaries, and the
consequently diminished velocity and increased lateral spread of the

streams which flow into them, have converted thousands of leagues of
shallow sea and fertile lowland into unproductive and miasmatic
morasses.
Besides the direct testimony of history to the ancient fertility of the
now exhausted regions to which I refer--Northern Africa, the greater
Arabian peninsula, Syria, Mesopotamia, Armenia and many other
provinces of Asia Minor, Greece, Sicily, and parts of even Italy and
Spain--the multitude and extent of yet remaining architectural ruins,
and of decayed works of internal improvement, show that at former
epochs a dense population inhabited those now lonely districts. Such a
population could have been sustained only by a productiveness of soil
of which we at present discover but slender traces; and the abundance
derived from that fertility serves to explain how large armies, like those
of the ancient Persians, and of the Crusaders and the Tartars in later
ages, could, without an organized commissariat, secure adequate
supplies in long marches through territories which, in our times, would
scarcely afford forage for a single regiment.
It appears then, that the fairest and fruitfulest provinces of the Roman
Empire, precisely that portion of terrestrial surface, in short, which,
about the commencement of the Christian era, was endowed with the
greatest superiority of soil, climate, and position, which had been
carried to the highest pitch of physical improvement, and which thus
combined the natural and artificial conditions best fitting it for the
habitation and enjoyment of a dense and highly refined and cultivated
population, are now completely exhausted of their fertility, or so
diminished in productiveness, as, with the exception of a few favored
oases that have escaped the general ruin, to be no longer capable of
affording sustenance to civilized man. If to this realm of desolation we
add the now wasted and solitary soils of Persia and the remoter East
that once fed their millions with milk and honey, we shall see that a
territory larger than all Europe, the abundance of which sustained in
bygone centuries a population scarcely inferior to that of the whole
Christian world at the present day, has been entirely withdrawn from
human use, or, at best, is thinly inhabited by tribes too few in numbers,
too poor in superfluous products, and too little advanced in culture and

the social arts, to contribute anything to the general moral or material
interests of the great commonwealth of man.

Causes of this Decay.
The decay of these once flourishing countries is partly due, no doubt, to
that class of geological causes whose action we can neither resist nor
guide, and partly also to the direct violence of hostile human force; but
it is, in a far greater proportion, either the result of man's ignorant
disregard of the laws of nature, or an incidental consequence of war and
of civil and ecclesiastical tyranny and misrule. Next to ignorance of
these laws, the primitive source, the causa causarum, of the acts and
neglects which have blasted with sterility and physical decrepitude the
noblest half of the empire of the Caesars, is, first, the brutal and
exhausting despotism which Rome herself exercised over her
conquered kingdoms, and even over her Italian territory; then, the host
of temporal and spiritual tyrannies which she left as her dying curse to
all her wide dominion, and which, in some form of violence or of fraud,
still brood over almost every soil subdued by the Roman legions.
[Footnote: In the Middle Ages, feudalism, and a nominal Christianity,
whose corruptions had converted the most beneficent of religions into
the most baneful of superstitions, perpetuated every