THE SALTS OF THE SEA. 179 



CHAPTER IX. 



THE SALTS OF THE SEA. 



Why is the Sea Saltl <J 49L— An Hypothesis, 494.— The Adaptations of the Sea, 498. 

 — Components of Sea Water every where alike, 500. — Proportion of soHd Contents, 

 502. — The Influence of Wind upon the Circulation of the Sea, 508. — The Influence 

 of Heat, 511. — The Influence of Evaporation, 517. — The Influence of Precipitation, 

 519. — Under Current from the Mediterranean and Red Sea due to the Salts of, 523. 

 — Space that the Salts of the Sea would occupy in a Solid State, 527. — De Haven's 

 Drift from the Arctic Ocean, 530. — An under Current flowing into it, 534. — The 

 Water Sky, 540. — Sea Shells, 545. — Their Agency in the System of Oceanic Circu- 

 lation, 548. — They assist to regulate Climate, 557. — Compensation in the Sea, 563. 

 — Insects of the Sea, 565. — Geological Records concerning the Salts of the Sea, 

 568.— Light from the Bible, 571. — Whence come the Salts of the Seal 574.— Pro- 

 fessor Chapman's Experiments, 579. 



490. In order to comprehend aright the currents of the sea, and 

 to study with advantage its physical adaptations, it is necessary to 

 understand the effects produced by the salts of the sea upon the 

 equilibrium of its waters ; for wherever equilibrium be destroyed, 

 whether in the air or water, it is restored by motion, and motion 

 among fluid particles gives rise to currents, which, in turn, consti- 

 tute circulation. 



This chapter is therefore added as a sort of supplement, which 

 will assist us in elucidating what has been advanced concerning 

 the currents of the sea. 



491. The question is often asked, "Why is the sea salt?" I 

 think it can be shown that the circulation of the ocean depends, 

 in a great measure, upon the salts of sea water ; certainly its in- 

 flences upon climate are greatly extended by reason of its salt- 

 ness. 



492. As a general rule, the sea is nearly of a uniform degree of 

 saltness, and the constituents of sea water are as constant in their 

 proportions as are the components of the atmosphere. It is true 

 that we sometimes come across arms of the sea, or places in the 

 ocean, where we find the water more salt or less salt than sea 



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