26 SALTNESS OF TEE OCEAN, 



most perfect representation of perpetual motion, penetrating 

 everything, passing everywhere, always present, in sight or 

 out of sight, and everywhere producing a marked effect. 

 When it is remembered that a very large proportion of the 

 w^eight of every living being, animal or vegetable, consists 

 of water, and that for life to continue at all, an incessant 

 supply of fresh fluid is required, the necessity of water will 

 be fully understood. 



The Saltness which distinguishes the waters of the ocean 

 is explained by the circumstance that chloride of sodium 

 (common salt) and other dissolvable salts, which form essen- 

 tial ingredients of the earth, are being constantly washed 

 out of the soil and rocks by rain and springs, and carried 

 down by the rivers ; and as the evaporation which feeds the 

 rivers carries none of the dissolved matter back to the land, 

 the tendency is to accumulate in the sea. We know that 

 beds of rock-salt, of enormous thickness, form part of the 

 crust of the globe; and Ave may infer that immense banks of 

 salt exist in the bed of the deep. The uniformity of this 

 saltness is preserved by the constant movement of the 

 waters, caused by the regular and perpetual action of the 

 winds. It has been said that if all the salts of the sea were 

 spread equally over the northern half of this continent, it 

 would cover the ground to the depth of one mile I What 

 force could move such a mass of matter on dry land ? Yet, 

 the machinery of the ocean, of which it forms a part, is so 

 wisely, marvelously, and wonderfully compensated, that the 

 most gentle breeze that plays on its bosom — the tiniest in- 

 sect that secretes solid matter for its sea-shell — is capable of 

 putting it instantly in motion. Still, when solid and placed 

 in a heap, all the mechanical contrivances of mankind, aided 

 by the tremendous forces of all the steam and water power 

 of the world, could not move so much as an inch in centuries 

 of this matter, which the sunbeam, the zephyr, and the in- 

 fusorial insect keep in perpetual motion and activity. 



