CETACEANS. 165 



parasites, often to the extent of resembling a rugged 

 rock.* 



The essential parts which compose the integuments 

 are the same as in quadrupeds. The epidermis, or scarf- 

 skin, is exceedingly delicate ; being no thicker than the 

 membrane known as ee gold-beaters'-skin." It is trans- 

 parent, of a pale-brown colour, and, after the death of 

 the whale, is readily and easily detached from the body. 



Beneath this covering is a thick layer of colouring 

 matter, or rete mucosum, (the " black-skin" of whalers,) 

 of firm, elastic, or doughy consistence, and dull, or gray- 

 black colour. When exposed to the air, its surface 

 hardens, becomes polished, and may be repeatedly 

 peeled off in sheets, which are sometimes preserved by 

 sailors and exhibited as the " skin of the whale." 



I scarcely need observe, that upon this structure the 

 colour of the Cachalot depends ; but it is worthy of 

 remark, that in those parts where the body of the 

 animal is white, this substance is not absent, but 

 resembles curds of milk, or flour-paste. 



The black-skin possesses a powerful alkaline pro- 

 perty, both in its recent state and when burned to 

 ashes. In the latter form it resembles powdered char- 

 coal, and communicates to water all the qualities of a 

 caustic alkali. Chemical analysis proves, that it derives 

 this power from a large proportion of free soda which 

 enters into its composition.f 



* It is the opinion of whalers, that both the Sperm and True-Whales 

 occasionally frequent heavy surfs, and roll in the billows, to free their 

 skin from extraneous matters. 



f A similar alkaline principle resides in the same structure in other 

 cetaceans ; although the fact would appear to have escaped the notice 

 of chemists and naturalists. It proves of very essential convenience to 

 the whaler, by enabling him readily to cleanse his ship and clothes from 

 oil, with which it combines perfectly, forming an extemporaneous soap. 



