DISINTEGRATION OF COAST. 467 



spray touches them they begin to feel the slow 

 but certain influence of the process of decay. 

 Rocks of all varieties of composition, serpentine, 

 porphyry, clay slate, gneiss, limestone, granite, 

 all waste under the gentle touch of the air and 

 foam, and become thus prepared to submit to 

 the force of the overwhelming surges which at 

 times are cast upon them. The soluble portions 

 of the rocks thus exposed become separated and 

 dissolved out by the waves, the surface loses its 

 solidity and compactness, and may be found on 

 examination covered for some inches in depth 

 with a layer of disintegrated matter, which only 

 awaits the coming of the first tempest to be torn 

 off and borne away by the triumphant waters 

 to the depths of the sea. The oxygen and car- 

 bonic acid gases held in solution by the waves 

 are largely instrumental in effecting this process, 

 and those portions of the rocks which are sub- 

 merged, although less influenced than the parts 

 exposed to the air and consequently to greater 

 vicissitudes of temperature, are nevertheless gra- 

 dually destroyed by this means. 



The matter thus produced accumulates at 

 the base of the cliffs, and it may be observed 

 forming a sort of low mound at their foot along 

 the rocky portions of the coast, there to remain, 

 however, only for a time. This leads us, there- 

 fore, to ask what becomes ultimately of this 



