10 MODERN E'ORES'if ECOlJoMY. 



of the fibrous rootlets which held it together, dried and 

 pulverised by sun and wind, and at last exhausted by new 

 combinations. The face of the earth is no longer a sponge, 

 but a dust heap ; and the floods which the waters of the 

 sky pour over it hurry swiftly along its slopes, carrying^ in 

 suspension vast quantities of earthy particles, which 

 increase the . abrading power and mechailical force of the 

 current, and, augmented by the sand and gravel of falling 

 banks, fill the bed of the streams, divert them into new 

 channels, and obstruct their outlets. The rivulets, wanting 

 their former regularity of supply, and deprived of the 

 protecting shade of the woods, are heated, evaporated, and 

 thus reduced in their former currents, — ^but swollen to 

 raging torrents in autumn and in spring. 



' From these causes there is a constant degradation of 

 uplands, and a consequent elevation of the beds of water- 

 courses, and of lakes, by the deposition of the mineral 

 and vegetable matter carried down by the waters. The 

 channels of great rivers become unnavigable, their estuaries 

 are choked up, and harbours which once sheltered large 

 navies are shoaled hy dangerous sand-bars. 



' The earth stript of its vegetable glebe grows less and 

 less productive, and consequently less able to protect 

 itself by weaving a new, net-work of roots to bind its 

 particles together, a new carpeting of turf to shield it from 

 wind and sun and scouring rain. Gradually it becomes 

 altogether barren. The washing of the soil from the 

 mountains leave bare ridges of sterile rock, and the rich 

 organic mould which covered them, now swept down into 

 the dark low grounds, promotes a luxuriance of aquatic 

 vegetation that breeds fever and more insidious forms of 

 mortal disease by its decay, and thus the earth is rendered 

 no -longer fit for the habitation of man.' 



But this is only one of many evils. At different times 

 and in different countries there has been raised a cry 

 that the destruction of forests was being carried on too 

 rapidly Siud too extensively; and consequent evils have 



