ON THE ALLUVIAL DEPOSITS. 361 



currents, even under the rational views formerly 

 given : but if the strata brought up the loose subma- 

 rine deposits when they were elevated, this difficulty 

 vanishes ; while the currents then produced will also 

 account for the transportation of the materials, and 

 further explain the difficulty of pointing out instances 

 so demonstrable as those of Italy. 



Thus, we may probably explain, under a principle 

 never yet imagined by geologists, yet resting on de- 

 monstrated facts, many, if not all of those trouble- 

 some cases of alluvia, transported or otherwise, which 

 have given rise to such absurd theories as those of 

 De Luc and others : while it is also plain that the 

 "debacles" of Saussure demand what he did not 

 know, to become an intelligible theory of much that 

 he had vainly attempted to explain. The boulders 

 are ready : it is only to distribute them : and the 

 power to distribute is in the same place. Even such 

 granite boulders as those of Isla thus cease to be a 

 difficulty, if we consider them to be the remains of 

 the submarine alluvia, brought up together with the 

 island : while it is easy to see, universally, how every 

 lighter material must have been removed by that power 

 of rain which carries off the solid surface itself. I 

 should further add, that such alluvia may become ulti- 

 mately associated with those of the present ocean 

 which I have separated from the tertiary formations : 

 or rather, become the same thing, under similar causes; 

 since I have shown that many of these, as they are 

 now situated, depend on elevations of the land,although 

 gradual ones. This is one of those frequent cases 

 where systems of classification become imperfect ; but 

 if geologists will consent that both cases shall be 

 ranked as alluvial, the needful distinction becomes 

 easily made. And if the organic substances, jet and 



