THE ARCTIC SEAS. 151 
bably aware that the body of the Whale is encased in 
a thick coat of fat, denominated blubber, varying in 
diameter from eight inches to nearly two feet in dif- 
ferent parts of the animal. It has, however, been only 
recently known that this fat lies not under the skin, 
but actually in its substance. I shall describe this in 
the words of Professor Jacob, who first made known 
this interesting peculiarity:—“That structure in 
which the oil is deposited, denominated blubber, is 
the true skin of the animal, modified certainly for 
the purpose of holding this fluid oil, but still being 
the true skin. Upon close examination it is found 
to consist of an interlacement of fibres, crossing each 
other in every direction, as in common skin, but more 
open in texture, to leave room for the oil. Taking 
the hog as an example of an animal covered with an 
external layer of fat, we find that we can raise the 
true skin without any difficulty, leaving a thick layer 
of cellular membrane, loaded with fat, of the same 
nature as that in the other parts of the body; on the 
contrary, in the Whale it is altogether impossible to 
raise any layer of skin distinct from the rest of the 
blubber, however thick it may be; and, in flensing a 
Whale, the operator removes this blubber or skin 
from the muscular parts beneath, merely dividing 
with his spade the connecting cellular membrane.”* 
Such a structure as this, being firm and elastic in the 
highest degree, operates like so much India-rubber, 
possessing a density and power of resistance which in- 
creases with the pressure. But this thick coating of 
fat subserves other important uses. An inhabitant 
* Dublin Philos. Journ. i. 356. 
