STATEMENT BY M. SURELL. 241 



opposed to the fixing of grounds, which renders them so mobile, and 

 draws torrents thither, is precisely the quality which renders them 

 favourable to the development of vegetation. The same cause which 

 multiplies the torrents ought then to multiply also the robust forests, 

 and to cause productiveness succeed in the long run to barrenness, 

 and stability to disorder ; not that, strictly speaking, there can be 

 in nature anything otherwise than orderly, for there is nothing which 

 is not subject to the rule of immutable laws, but in popular phrase 

 the term disorder has also its meaning. 



" One is struck with the illustrations of the observation which has 

 just been made in going over certain forests in these mountains. One 

 sees the vegetation doubling its profusion and energy in grounds torn 

 by ravines, and crumbling on aU hands, as if it were mustering its 

 last efforts to retain a soil escaping from it. To cite one example : 

 in the forest of Boscodon may be seen the vigour and tenacity of the 

 vegetation contending against a friable soil composed of schist, tufa, 

 and gypsum. It is, in fact, the lands which are the most mobile 

 which are at the same time the most fertile, and the hard rocks on 

 which vegetation has no hold, brave also the effort put forth by all 

 the causes of destruction. The mountains, if they were abandoned 

 quite naked to external influence, would soon be levelled or cut up 

 into bits, and they would offer to man nothing but a heap of cleft 

 rocks, uncultivated and uninhabited. 



" It is vegetation which prevents this ruin ; and as there can be no 

 vegetation without water, it is on the mountains that nature has poured 

 out the water in the greatest profusion. We have already called 

 attention to the remark, that there faUs more rain on the mountains 

 than on the plains. The mountains attract and retain the clouds p]. 

 Snows and glaciers crown their summits as immense reservoirs, whence 

 trickles out a perpetual moisture, and whence flow innumerable 

 streamlets which fertilize their sides, and distribute fertihty, from 

 brow to brow, down to the very depth of the valleys. Thus, the 

 waters which are the most energetic means of destroying the soil are 

 at the same time the most active in its conservation. In drawing on 

 vegetation, they preserve the soil against their own attacks, and the 

 more they have of power to destroy, the more vegetation they cause 

 to spring up to preserve. It is in this way that nature imposes on 

 all her forces moderators which counterbalance them and keep them 

 from acting always in the same way ; and this must end in bringing 

 everything to a state of restored peace." 



After dwelUng on the thought of self-adjusting provision for the 



2o 



