TOBBBNTB OP THE HIGH ALPS. 47 



U8 to admit that forests exercise a powerful influence on the production of 

 torrents, whether it be by standing on the soil they defend it against their 

 approach, or, obliterated by the hand of man they leave to them an open 

 field which they are not slow to devastate 1 



" It is of importance to establish the fact of this influence by direct and 

 positive proofs. Here we are almost embarassed by the very amount of 

 evidence. It should be known that this influence manifests itself here in so 

 many varied circumstances, in such a variety of forms, and with such a 

 force of truth, that assuredly not one man throughout the whole country 

 would dare to dispute it. It is only necessary to spend one day traversing 

 these mountains to be struck with an infinity of facts fitted to produce 

 conviction in opposition to the 'most rooted prejudice to the contrary. All 

 of those who know the country can have, on this point, but one opinion. 

 All the observations on this matter which have been published are of 

 one accord, and the authors have had no other trouble than to verify the 

 public opinion, nor other merit than to express by the pen that which has 

 been for many ages in all mouths and in all minds." 



In face of a belief so universal, so little disputed, and so indisputable, 

 one finds himself at a loss when he tries to reduce it to a kind of demon- 

 stration ; he knows not how to select one from so great a number of cases, 

 which corroborate one another, and the force or power of which lies in their 

 cumulation ; and he thus writes on the influence of forests on the extinction 

 of torrents : — " In examining the basins drained by great extinct torrents, 

 there are almost always found there forests, and often dense forests. There 

 may be observed also, along wooded revers, a number of small torrents of the 

 third class, which appear as if stifled under the mass of vegetation, and are 

 completely extinct. Now this second observation, which can be verified by 

 a multitude of examples, supplies a demonstration of a fact of which the 

 first only permitted us to entertain a suspicion in a vague way : — it is, that 

 the forests are capable of bringing about the extinction of a torrent already 

 formed. Indeed, it is impossible to admit that the small torrents, dug for 

 the most part in mobile and friable ground, can have died of themselves, so 

 to speak, in their very birth, and through the effect alone of that equili- 

 brium to which reference has already been made. 



" Stability cannot establish itself so speedily on beds which are scarcely 

 formed, and in the midst of lands which offer still so much food for erosion 

 by the waters ; it is a work which demands time, and which is never entirely 

 consummated until the mountain has been gnawed away to the quick, and 

 to its last ridge. 



" Aifiongst the great number of extinct torrents, the basins of which are 

 wooded, there are some the forests of which have been subjected to the 

 commune r&gvme, and have fallen in part under the axe of the inhabitants. 

 Very well, the result of this destruction of trees has been to rekindle the 

 violence of the torrents, which only slumbered. There have been seen thus 

 peaceful streams give place to furious torrents, which the fall of the wood 

 had re-awakened from their long sleep, and which vomited forth new masses 

 of dejection on beds of deposit, which had been cultivated without suspicion 

 from time immemorial. This is what has been remarked more especially 

 after the excessive destruction of woods which followed the first years of the 

 Revolution j the devastations of many great torrents only date from this 

 epoch. It is from this time that the torrent of Merdanel has advanced 

 towards the village of Saint Cr^pin, the inhabitants of which are to-day 



