STATBMRNT RY M. SURELL. 237 



the occasion of all the disasters accompanying or following these 

 torrents ; and he urged the abandonment or regulation of these pro- 

 ceedings, and the rehoisement of the mountains, as means of arresting 

 and counteracting the evil. 



The commotions occasioned by the revolution prevented full effect 

 being given to these views at that time, but some fifty years later a 

 work was published by M. Alex. Surell, entitled Etude sur les Torrents 

 des Hautes Alpes, in which similar and more extended views of the 

 subject were advanced. This work was crowned by the Academy of 

 Sciences ; and it led to the commencement of extensive works of re- 

 hoisement on the mountains of France. These have been prosecuted 

 with energy and success at great expense, but ungrudgingly, — the 

 result having proved corroborative of the principles upon which they 

 were undertaken. It is only as illustrative of the soundness of the 

 views upon which these were founded that they are now referred to ; 

 and here I can only bring forward statements of these views and prin- 

 ciples, with a passing notice of results illustrative of their truth. 



M. Surell says : " When we examine the lands in the midst of which 

 are scattered the torrents of recent origin, we see them to be in every 

 case stripped of trees and of every kind of arborescent vegetation. 

 On the other hand, when we look at mountain sloj)es which have been 

 recently stripped of woods, we see them to have been gnawed away 

 by innumerable torrents of the third class, which evidently can only 

 have been formed in later years. 



" See then a very remarkable double fact : everywhere where there 

 are recent torrents there are no more forests : and wherever the soil 

 has been stripped of wood recent torrents have been formed ; so that 

 the same eyes which have seen the forest felled on the slope of a 

 mountain have there seen incontinently a multitude of torrents." 



And again, " 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 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 



