LECTURE IV. 147 



ralk-d Sperma-Ceti Whales, is distinguished \>y 

 having visible teeth in tin- Io\\crjaw only, which 

 \\hi-ii the mouth is dosed, are received into so 

 inaiiv open socket* in the upper jaw : an accurate 

 inspection <>f the upper jaw h that 



there are cor respond! n i in that al-o, but 



thev are very small, and situated so deep within 

 the sockets as to be totally invisible on a general 

 view. 



The Physeter Macrocephalus, or great Sper- 

 maceti Whale, is not greatly inferior in size to the 

 Great Whah hone Whale or Mysticeto, and is of a 

 shape not less uncouth; the head being of so 

 a >i/e a^ at Ica.-t to equal a third of the length of 

 the whole animal. It is from this Whale, as well 

 as from some others of this genus, that the well- 

 known substance popularly known by the name of 

 Spermaceti is obtained. This substance, v.h.ch 

 in the living animal is a liquid oil, is contained in 

 a vast cellular cavity within the head; when ex- 

 posed to thi f cold air, it concretes into a 

 solid form: it exists in other parts of the animal, 

 as well as in the head, and may be gained from 

 the blubber or common oil by proper preparation: 

 in a smaller proportion also it is found to exist in 



