THE SALTS OF THE SEA. 247 



mollnsk or coralline, we will suppose, commences his secretions, and 

 abstracts from the sea water (§ 465) soHd matter for his cell. In 

 that act this animal has destroyed the equihbrium of the w^hole 

 ocean, for the specific gi'avity of that portion of water from w^hich 

 this sohd matter has been abstracted is altered. Having lost a 

 portion of its sohd contents, it has become specifically fighter than 

 it was before ; it must, therefore, give place to the pressure which 

 the heavier w^ater exerts to push it aside and to occupy its place, 

 and it must consequently travel about and mingle with the w^aters 

 of the other parts of the ocean until its proportion of solid matter 

 is retmned to it, and until it attahis the exact degree of specific 

 gravity due to sea water generally. 



486. How much sohd matter does the whole host of marine 



Solid matter secreted plants and auimals abstract from sea water daily? 



by them. jg j^ ^ thousaud pouuds, or a thousand milhons of 



tons ? No one can say. But, whatever be its weight, it is so 



much of the power of gravity applied to ^ the dynamical forces of 



the ocean. And this power is derived from the salts of the sea, 



through the agency of sea-shells and other marine animals, that 



of themselves scarcely possess the power of locomotion. Yet they 



have power to put the w^hole sea in motion, from the equator to 



the poles, and from top to bottom. But we have yet to inquire 



how far may cm-rents be due to the derangement of equihbrium 



arising from the change of specific gravity caused by the secretions 



of the myriads of marine animals that are continually at work in 



various parts of the ocean. These httle creatures abstract from 



sea water sohd matter enough to build continents of. And, also, 



we have to remember as to the extent to which equihbrium in the 



sea is distm'bed by the salts which evaporation leaves behind. Thus, 



w^hen we consider the salts of the sea m one point of view, w^e see 



the winds and the marine animals operating upon the waters, and, 



in certain parts of the ocean, developing by their action upon the 



solid contents of the same those very principles of antagonistic 



forces which hold the earth in its orbit, and preserve the harmonies 



of the universe. 



487. From another point of view, we see the sea-breeze and the 

 Dynamical force de- sea-shell, m performing their appointed offices, so 

 rived from. actiug as to givo risc to a reciprocating motion in 



the waters ; and thus they impart to the ocean dynamical forces 

 also for its circulation. The sea-breeze plays upon the surface ; 

 it converts only fresh water into vapour, and leaves the solid mat- 



