The Rorqual— The Spermaceti Wliale. 407 
THE KORQUAL, OR FIN-BACKED WHALE, 
(Balcenoptera boops,) 
Is a very large Whale, specimens sometimes measuring 
as much as one hundred feet in length. It is distinguished 
by its smaller head, and by the existence of a sort of fin 
on the lower part of its back. The Rorqual is found in 
the northern seas, and specimens are sometimes seen off 
our coasts. It is not of much value, as it furnishes far 
less blubber than the common Whale, and the baleen or 
whalebone is so short as to be useless. 
THE SPERMACETI WHALE, OR CACHALOT. 
(Physeter macrocephalus.) 
This animal has teeth in the lower jaw onl} r ; and no 
whalebone. The substance called spermaceti is extracted 
from its immense head, which is nearly half the size of 
the entire animal ; and the throat is so large that it could 
swallow a shark. 
The quantity of oil produced from the Spermaceti 
Whale is not so considerable as that obtained from the 
common or Greenland Whale, but in quality it is far 
preferable, as it yields a bright flame, without exhaling 
any nauseous smell. The substance known by the' 
