CHEMICAL EFFECT OF WAVES. 473 



pointed, it at length totters, becomes crested 

 with foam, curves over, breaks with great vio- 

 lence, and, continuing to break, is gradually 

 lessened in a bulk, until it ends in a fringed 

 margin on the sea-shore a broken and agi- 

 tated mass of foam. Nothing could be more 

 perfect than the manner in which the water 

 and air are thus commingled; and the hissing 

 of innumerable air-bubbles, as they burst on 

 the surface, impresses forcibly upon the mind 

 of the thoughtful observer, the conviction that 

 such a process of agitation as this is neither 

 without its effect, nor doubtless without its 

 intention. 



From what has been already said upon the 

 chemistry of the sea, it will be evident that the 

 solution of the gas oxygen, in water, is of the 

 most vital importance to the marine inhabit- 

 ants. Much of this oxygen, as we shall yet 

 have to notice, is obtained by vital processes ; 

 but, as we look along the shore, white with the 

 foam of countless waves ; as we remember the 

 intimate manner in which air is thus mingled 

 with water, and reflect upon the incessant con- 

 tinuance of the same phenomenon, can we doubt 

 that, in the same manner also, a large quantity 

 of this valuable ingredient is added to the waters 

 for the service of the inhabitants of the sea ? In 

 consequence of the slight solubility of oxygen 



