320 PHYSICAL GEOGEAPHY OF THE SEA, AND ITS METEOHOLOGY. 



618. The waters of the Mississippi and the Amazon, together 

 The work of re- wlth -all the stroams and rivers of the world, both 

 caiTied on.' '^^^ great and small, hold in solution large quantities of 

 lime, soda, iron, and other matter. They discharge annually into 

 the sea an amount of this soluble matter, which, if precipitated and 

 collected into one solid mass, would no doubt sm-prise and astonish 

 even the boldest speculator with its magnitude. This soluble mat- 

 ter cannot be evaporated. Once in the ocean, there it must re- 

 main ; and as the rivers are continually pouring in fresh supphes 

 of it, the sea, it has been argued, must continue to become more 

 and more salt. Now the rivers convey to the sea this solid mat- 

 ter mixed with fresh water, which, being lighter than that of the 

 ocean, remains for a considerable tune at or near the surface. 

 Here the microscopic organisms of the deep-sea lead are continu- 

 ally at work, secreting this same hme and soda, etc., and extract- 

 ing from the sea water all this solid matter as fast as the rivers 

 bring it down and empty it into the sea. Thus we haul up from 

 the deep sea, specimens of dead animals, and recognize in them the 

 remains of creatures which, though invisible to the naked eye, 

 have nevertheless assigned to them a most important office in the 

 physical economy of the universe, viz., that of regulating the salt- 

 ness of the sea (§ 489). This view suggests many contemplations. 

 Among them, one, in which the ocean is presented as a vast chemi- 

 cal bath, in which the solid parts of the earth are washed, filtered, 

 and precipitated again as solid matter, but in a new form, and with 

 fresh properties. Doubtless it is only a readaptation — though it 

 may be in an improved form — of old, and perhaps effete matter, to 

 the uses and well-being of man. These are speculations merely ; 

 they may be fancies without foundation, but idle they are not, I 

 am^ sure ; for when we come to consider the agents by which the 

 physical economy of this Qur earth is regulated, by wdiich this or 

 that result is brought about and accomplished in this beautiful sys- 

 tem of terrestrial arrangements, we are utterly amazed at the offices 

 which have been performed, the work w^hich has been done, 

 by the animalculse of the water. But whence come the little sih- 

 cious and calcareous shells which Brooke's lead has brought up, 

 in proof of its sounding, from the depth of over two miles ? Did 

 they live in the sm'face waters immediateh" above ? or is then- 

 habitat in some remote part of the sea, whence, at their death, the 

 currents were sent forth as pall-bearers, with the command to de- 

 posit the dead corpses where the plummet found them ? 



