THE SALTS OF THE SEA. 195 



current, which, "because it comes from toward the equatorial re- 

 gions, comes from a milder climate, and is therefore warmer, we 

 can easily imagine why there might be an open sea in the Polar 

 regions — why Lieutenant De Haven, in his instructions (§ 482), 

 was directed to look for it ; and why both he and Captain Penny, 

 of one of the English searching vessels, and afterward Dr. Kane, 

 found it there. 



543. And in accounting for this polynia, we see that its exist- 

 ence is not only consistent with the hypothesis with which we set 

 out, touching a perfect system of oceanic circulation, hut that it 

 may be ascribed, in a great degree at least, if not wholly, to the 

 effect produced by the salts of the sea upon the mobility and cir- 

 culation of its waters. 



544. Here, then, is an office which the sea performs in the econ- 

 omy of the universe by virtue of its saltness, and which it could 

 not perform were its waters altogether fresh. And thus philoso- 

 phers have a clew placed in their hands which will probably guide 

 them to one of the many hidden reasons that are embraced in the 

 true answer to the question, *' Why is the sea salt?" 



545. Sea Shells. — We find in sea water other matter besides 

 common salt. Lime is dissolved by the rains and the rivers, and 

 emptied in vast quantities into the ocean. Out of it, coral islands 

 and coral reefs of great extent — marl-beds, shell-banks, and in- 

 fusorial deposits of enormous magnitude have been constructed by 

 the inhabitants of the deep. These creatures are endowed with 

 the power of secreting, apparently for their own purposes only, 

 solid matter, which the waters of the sea hold in solution. But 

 this power was given to them that they also might fulfill the part 

 assigned them in the economy of the universe. For to them, 

 probably, has been allotted the important office of assisting in 

 giving circulation to the ocean, of helping to regulate the cli- 

 mates of the earth, and of preserving the purity of the sea. 



546. The better to comprehend how such creatures may influ- 

 ence currents and climates, let us suppose the ocean to be per- 

 fectly at rest — that throughout, it is in a state of complete equi- 

 librium — that, with the exception of those tenants of the deep 

 which have the power of extracting from it the solid matter held 



