216 THE PHYSICAL GEOGRAPHY OF THE SEA. 



The microscope, under the eye of Ehrenberg, has enabled us 

 (§ 158) to put talhes on the wings of the wind, to learn of them 

 somewhat concerning its " circuits." 



Now, may not these shells, which were so fine and impalpable 

 that the officers of the Dolphin took them to be a mass of unctu- 

 ous clay — may not, I say, these, with other specimens of sound- 

 ings yet to be collected, be all converted by the microscope into 

 tallies for the waters of the different parts of the sea, by which 

 the channels through which the circulation of the ocean is car- 

 ried on are to be revealed ? 



Suppose, for instance, that the dwelling-place of the little shells 

 which compose this specimen from that part of the ocean be ascer- 

 tained, by referring to living types, to be the Gulf of Mexico or 

 some other remote region ; that the habitat and the burial-place, 

 in every instance, be far removed from each other — by what agen- 

 cy, except through that of currents, can we suppose these little 

 creatures — themselves not having the powers of locomotion — to 

 come from the place of their birth, or to travel to that of their 

 burial ? 



Man can never see — he can only touch the bottom of the deep 

 sea, and then only with the plummet. Whatever it brings up 

 thence is to the philosopher matter of powerful interest ; for by 

 such information alone as he may gather from a most careful ex- 

 amination of such matter, the amount of human knowledge con- 

 cerning nearly all that portion of our planet which is covered by 

 the sea must depend. 



Every specimen of bottom from the deep sea is, therefore, tc 

 be regarded as probabl}^ containing something precious in the wa}- 

 of contribution to the sources of human knowledge. 



