204 THE PHYSICAL GEOGRAPHY OF THE SEA. 



earth with solid matter that has been secreted from brinj waters, 

 or those infusorial deposits which astound the geologist with their 

 magnitude and extent, or those fossil remains of the sea which 

 have astonished, puzzled, and bewildered man in all ages — whence, 

 had not the sea been salt when its metes and bounds were set, 

 could these creatures have obtained solid matter for their edifices 

 and structures. Much of that part of the earth's crust which man 

 stirs up in cultivation, and which yields him bread, has been made 

 fruitful bj these "salts," which all manner of marine insects, 

 aqueous organisms, and sea-shells have secreted from the ocean. 

 Much of this portion of our planet has been filtered through the 

 sea, and its insects and creeping things are doing now precisely 

 what they were set about when the dry land appeared, namely, 

 preserving the purity of the ocean, and regulating it in the due 

 performance of its great offices. As fast as the rains dissolve the 

 salts of the earth, and send them down through the rivers to the 

 sea, these faithful and everlasting agents of the Creator elaborate 

 them into pearls, shells, corals, and precious things ; and so, while 

 they are preserving the sea, they are also embellishing the land 

 by imparting new adaptations to its soil, fresh beauty and variety 

 to its landscapes. 



573. In every department of nature there is to be found this 

 self-adjusting principle — this beautiful and exquisite system of 

 compensation, by which the operations of the grand machinery of 

 the universe are maintained in the most perfect order. 



574. Whence came the salts of the sea originally is a question 

 which perhaps never will be settled satisfactorily to every philo- 

 sophic mind, but it is sufficient for the Christian philosopher to rec- 

 ollect that the salts of the sea, like its waters and the granite of 

 the hills, are composed of substances which, when reduced to their 

 simple state, are found for the most part to be mere gaseous or 

 volatile matter of some kind or other. Thus we say that granite 

 is generally composed of feldspar, mica, and quartz, yet these three 

 minerals are made of substances more or less volatile in combina- 

 tion with oxygen gas. Iron, of which there is merely a trace, is the 

 only ingi-edient which, in its uncombined and simple state, is not 

 gaseous or volatile. Now was the feldspar of the granite origin- 



