16 Structure and Economy 



scarcely less in the diving birds ; and it is, perhaps, occasioned 

 by the slow return of the venous blood to the heart, during fre- 

 quent submersion, by which it probably acquires a superabun- 

 dance, or an extra quantity of carbon. In ourselves, it may be 

 added, that the same appearance of the blood is produced, by 

 artificially arresting its progress in the veins ; and that which is 

 slowly drawn from the arm is, on the same principle, much 

 darker than that which flows freely ; a circumstance, even to the 

 present day, often erroneously attributed to a morbid state of 

 that fluid. 



I shall now endeavour to describe to you another interesting 

 peculiarity in the whale tribes. Beneath their smooth skins, the 

 bodies of these animals are well known to be surrounded by an 

 enormously thick membrane, which contains a prodigious quan- 

 tity of fluid oil. This fluid oil, in like manner, pervades every 

 part of the substance of their bones, which, milike those of 

 quadrupeds, are not hollow, but entirely spongy or cellular. 



The blubber, or membrane, which contains the oil, varies, in 

 the common whale, in its depth ; it is two feet thick in several 

 situations, especially across the back of the neck ; but it even 

 extends to three feet in thickness in the lip, near the angle of 

 the mouth. It is comparatively the most abundant, and the 

 oil is of the finest quality in young whales ; hence, a sucking 

 whale of nineteen feet long, and fourteen in circumference, has 

 been known to yield six tons of oil, although its whalebone was 

 not one foot in length, and far too short to enable it to catch 

 food. In young whales, also, the blubber is almost white ; in 

 others it is found of a yellowish colour ; and in some, appa- 

 rently from their partaking of a peculiar kind of nourishment, 

 it acquires almost the red appearance of the flesh of the salmon. 



The blubber may, I think, be considered as a less dense 

 portion of the true skin, consisting, in fact, as I have often seen 

 at Hull, of a strong tendinous membrane, whose fibres inter- 

 weave each other in every direction, and which contain the oil 

 within them ; but, when deprived of the oil, these fibres appear 

 like an irregular network of tendon, differing in the fineness of 

 its texture in different situations ; it being most compact, where 

 itis nearest to the surface of the body, and decreasing in its den- 

 sity as it dips downwards towards the muscles. In striking the 



