THE BASIN OF THE ATLANTIC. 
215 
fresh water, which, being hghter than that of the ocean, remains 
for a considerable time at or near the surface. Here the micro- 
scopic organisms of the deep-sea lead are continually at work, se- 
creting this Scime lime and soda, &c., and extracting 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 invis>. 
ible 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 (§ 342). 
This view suggests many contemplations. Among them, one 
in which the ocean is presented as a vast chemical 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 re-adaptation, though it may be in an im- 
proved form, of old, and, perhaps, eifete 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 our 
earth is regulated, by which this or that result is brought about 
and accomplished in this beautiful system of terrestrial arrange- 
ments, we are utterly amazed at the offices which have been per- 
formed, the work which has been done, by the animalcules of the 
water. 
459. 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 ? 
460. 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 circula- 
tion for many a long mile. 
