42 ON CHANGES IN THE DISPOSITION 



stration of the power, and the very great power, of this 

 most simple cause, so much overlooked, we may safely 

 apply it where no such evidence remains, and thus 

 admit Rain and its consequences as one of the great 

 agents in denudation. 



I can suggest but one more cause, and it is connected 

 with the present one. If it has a hypothetical ap- 

 pearance, it is consistent with the laws of philosophical 

 Theory to suggest probable consequences from causes 

 that can be inferred, though not proved. The reasons 

 have long since appeared, for a state of heat in the 

 waters which must have been attended by an extrava- 

 gant evaporation ; while the results have been admitted 

 very generally, though I may suppress all that has 

 been said respecting a chaotic atmosphere. Corre- 

 sponding descents of rain must have been the inevita- 

 ble consequence ; while something analogous occurs 

 in the case of volcanic eruptions: and thus is there a 

 power capable of producing the same effects, but to a far 

 greater extent; as it is also one which aids in solving 

 many of the difficult facts relating to alluvia. If I 

 did not suggest it formerly in speaking of Currents, 

 it is that I reserved it for this fitter place ; while I need 

 not say how it can be applied in aid of those causes 

 of great movements of waters on the surface of the 

 Earth which have been already suggested. 



On Changes in the Depth and Level of the Sea. 



As the outline of the sea varies, in consequence of the 

 transportation of the land, so does its depth. But as our 

 means of determining that variation are limited to the 

 shores and the shallower seas, we are unable to trace 

 that distribution of the marine alluvia along the bottom, 

 which can however often be inferred from circum- 

 stances. Though njuch of the materials brought down 



