THE BASIN OF THE ATLANTIC. 259 



microscopic organisms of the deep-sea lead are continually at work, 

 secreting this same lime and soda, etc., and extracting from the sea- 

 water all this solid matter as fast as the rivers bring it down and 

 empty it into the sea. They live and die at the surface, then 

 sinking, the bottom of the sea is strewed with them. 



739. Thus we haul up from the deep sea specimens of dead an- 

 imals, 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 saltness of the sea (§ 563). 



740. This view suggests many contemplations. Among them, 

 one in which the ocean is presented as a vast chemical bath, where 

 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 re-adaptation — though it may be in an im- 

 proved form — of old, and perhaps effete matter, to the uses and 

 well-being of man. 



741. These are speculations merely ; they may be fancies with- 

 out foundation, but idle they are not, I am sure ; for when we come 

 to consider the agents by which the physical economy of this our 

 earth is regulated, by which this or that result is brought about and 

 accomplished in this beautiful system of terrestrial arrangements, 

 we are utterly amazed at the offices which have been performed, 

 the work which has been done, by the animalcul^e of the water. 



742. But whence come the little calcareous shells which 

 Brooke's lead has brought up, in proof of its sounding, from the 

 depth of two miles and a quarter ? Did they live in the surface 

 waters immediately above ? or is their habitat in some remote part 

 of the sea, whence, at their death, the currents were sent forth as 

 pall-bearers, with the command to deposit their remains where the 

 plummet found them ? 



743. In this view, these little organisms become doubly inter- 

 esting. When dead, the descent of the shell to its final resting- 

 place would not, it may be supposed, be very rapid. It would 

 partake of the motion of the sea-water in which it lived and died, 

 and probably be carried along with it in its channels of circulation 

 for many a long mile. 



R 



