492 ACCOUNT OF THE AllCTIC REGIONS. 



and clean, while all the rest is rough and dirty ; 

 and especially from the circumstance of a broken 

 tusk being found, with the angles of the fractured 

 part rubbed down ^nd rounded, it is not improbable 

 but it may be used in piercing thin ice for the con- 

 venience of respiring, without being under the ne- 

 cessity of retreating into open water. It cannot, I 

 conceive, be used as many authors have stated, in 

 raking their food from the bottom of the sea; 

 because these animals are most commonly met with 

 in deep seas, where they would be incapable of sur- 

 viving under the immense pressure of the column 

 of water resting on the bottom. 



A quantity of blubber, from 2 to 3 4 inches in 

 thickness, and amounting sometimes to above half a 

 ton, encompasses the whole body. This affords a 

 large proportion of very line oil. The skull of the 

 narwal, like those of the Delphinus deductor, por- 

 pus, beluga, grampus, dolphin, &c., is concave above, 

 and sends forth a large flat wedge-shaped process in 

 front, which affords sockets for the tusks. Upon 

 this process is a bed of fat extending to the thick- 

 ness of 10 or 12 inches horizontally, (as the animal 

 swims,) and 8 or 9 perpendicularly. This fat gives 

 the round form to the head ; and by its greater or 

 lesser deposition, occasions a considerable difference 

 in the shape and prominence of the forehead. In 

 consequence of this, what has been called the facial 



