\ II. 



DELTAS OF THE GANGES AND MISSISSIPPI. 57 



loaded with adventitious matter ; and as the power of abra- 

 sion becomes greater, by the increase in the quantity and 

 density of the mass of water, a large proportion of the ma- 

 terials is suspended in the fluid, and carried into the sea. 

 If the current is feeble, much of the mud, and the larger 

 pebbles, will be thrown down in the bed of the river — hence 

 the formation of alluvial plains, as for example those in the 

 valleys of the Arun, the Adur, the Ouse, and Cuckmere, 

 in this county.* But a great quantity is transported to the 

 mouths of the rivers, and there forms those accumulations 

 of the fluviatile spoils of the land which constitute deltas ; 

 the finest particles, however, are carried far into the sea, 

 and, transported by currents and agitated by the waves, 

 are at length precipitated into the profound and tranquil 

 depths of the ocean. But rivers convey not only the mud 

 and other detritus of the countries through which they flow; 

 leaves, branches of trees, and other vegetable matter, and 

 the remains of the animals that fall into the streams, with 

 shells and other exuviae, human remains, and works of art, 

 are also constantly transported and imbedded in the silt and 

 sand of the deltas and estuaries, and some of these remains 

 are occasionally drifted out to sea, and deposited in its 

 bed. 



21. Deltas of the Ganges and Mississippi. — The 

 changes here contemplated, as they are going on in our own 

 island, may appear insignificant, and incapable of producing 

 any material effect on the earth's surface ; but if we trace 

 the results in countries where the agents under review are 

 operating on a larger scale, we shall at once perceive their 

 importance, and that time only is required for the accu- 

 mulation of strata, equal in extent and alike in character 

 with many of those ancient deposits, which will hereafter 

 come under our observation. 



Suss 



