267 



have been comparatively small ; for we may observe 

 at the present time, in deep forests during long con- 

 tinued and heavy rains, the water running oft', as I 

 have before remarked, into brooks that are scarcely 

 rendered turbid by alluvion. 



As the waters increase and descend from one chan- 

 nel to another, into the principal stream or river, its 

 waters are elevated ; and its shores, by being softened, 

 and in some instances excavated by currents, occasion 

 the banks to break off and fall down. This, mixing 

 with the current, adds to the quantity of alluvion, 

 which is borne away by the rapidity of the flood. 

 But a part, only, of this, as I have already stated, is 

 wafted to a very great distance ; for as soon as the 

 current is slackened, or checked in its progress, the 

 silicious part, or sand, is precipitated to the bottom ; 

 while the alluminous or clayey part, being much 

 lighter, is held long suspended and carried to a greai 

 distance. 



In this I am supported by the opinion of that very 

 acute observer Mr. Rennell, who says, "The mud 

 and sand suspended in these waters, during this mo- 

 tion, are deposited when that motion ceases ; or 

 rather, they are gradually deposited as the current 

 slackens : according to the gravity of the substances 

 that are suspended"* 



* Rennell's Herodotus, page 489, 



