Structure and Oeconomy of Whales. 38 r 
Seal has while alive ; the oil has the fame fmell with that 
of the Salmon, Herring, Sprat, &c. 
The observations refpeffing the weight of the flefh of ani- 
mals that fvvim, which I publifhed in my obfervations on the 
oeconomy of certain parts of animals, are applicable to thefe 
alfo ; for the flefh in this tribe is rather heavier than beef ; two 
portions of mufcle of the fame fhape, one from the pfoas mufcle 
of the Whale, the other of an ox, when weighed in air, were 
both exactly 502 grains ; but, weighed in water, the portion of 
the Whale was four grains heavier than the other. It is pro- 
bable, therefore, that the neceffary equilibrium between the 
water and the animal is produced by the oil, in addition to 
which the principal acdion of the tail is fuch as tends either 
to raife them, or keep them lufpended in the water, according 
to the degree of force with which it a£bs. 
From the tail being horizontal, the motion of the animal, 
when impelled by it, is up and down : two advantages are 
gained by this, it gives the neceffary opportunity of breathing, 
and elevates them in the water ; for every motion of the tail 
tends, as I faid before, to raife the animal : and that this may 
be effected, the greatefl: motion of the tail is downwards, thofe 
mufcles being very large, making two ridges in the abdomen ; 
this motion of the tail raifes the anterior extremity, which 
always tends to keep the body fufpended in the water. 
Of the Bones. 
The bones alone, in many animals, when properly united 
into what is called the fkeleton, give the general fhape and 
character of the animal. Thus a quadruped is diftinguifhed 
from a bird, and even one quadruped from another, it only 
requiring 
