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THE PHYSIOLOGY ОЕ DEEP-SEA LIFE. 303 
oceanic basins. And this is the temperature of all seas whick 
are not, like inland seas, subjected to special conditions ; as, for 
instance, the Mediterranean, the Red Sea, the Sulu Sea, the Car- 
ibbean, and the Gulf of Mexico. These all depend for their 
lowest bottom temperature on the height of the ridges separat- 
ing them from the general circulation. 
The differences of temperature observed over extensive areas 
in the Atlantic are easily explained by the presence of ridges 
rising to heights which isolate the western basin of the Atlantic 
from the eastern, and that protect these basins again from the 
indraught of cold water from the depths of the South Atlantic. 
We may thus find enclosed seas or circumscribed oceanic areas 
with higher bottom temperature than adjoining seas, due en- 
tirely to their exclusion from oceanic circulation by elevations 
of a portion of the bottom. 
The great cold of the bottom water of the ocean, even in the 
tropics, is best brought home to those who have examined the 
contents of a haul of the trawl under the tropics. The bottom 
ooze is intensely cold, and it is a strange sensation, while one’s 
back is broiling beneath a tropical sun, to have one’s hands 
nearly frozen from the stiff, cold mud or ooze one is compelled 
to handle while assorting the contents of the trawl. 
The increase of temperature as one passes into the interior 
of the earth does not affect the temperature of the bottom 
of the ocean, for there the constant renewal of cold water sup- 
plied from the poles keeps the temperature uniform even in the 
equatorial regions. Were the body of water affected in a sim- 
ilar manner as the solid crust of the earth, we should find about 
350° F. at a depth of three thousand fathoms. But if the in- 
creased heat of the interior of the earth’s crust is due to pres- 
sure, and not to solar agency through the absorption of heat, we 
can see some reason for a lower ocean temperature at correspond- 
ing depths, even were there no oceanic circulation. 
1 We followed the advice given by Com- 
mander Belknap to dredgers and sound- 
ers, to ice their wine in the common 
refrigerator ; but the fate of a small bot- 
tle of champagne, sent down to a depth 
of twenty-four hundred fathoms, was only 
encouraging to the friends of total absti- 
nence. It came back to us cold, it is 
true, but filled with muddy salt water, 
which had been forced through the foil 
and cork, and had replaced the more pala- 
table contents of the bottle. 
