152 DESTINATION OF NON-AZOTIZED ALIMENTS. 
to say that they are deposited as fat; since it is only when 
a large quantity of them is taken in, that there is any in¬ 
crease in the quantity of fat already in the body. We shall 
hereafter see that they are used up in the process of respira¬ 
tion, one great object of which is, to produce a certain amount 
of heat, sufficient to keep up the temperature of the body, in 
warm-blooded animals, to a high standard. We might almost 
say with truth, that a great part of the oleaginous and sac¬ 
charine principles is burned within the body, for this pur¬ 
pose. The process will be hereafter considered more in 
detail (§§ 412, 413) ; and at present we need only stop to 
remark upon the adaptation between the food provided for 
animals in different climates, and the amount of heat which 
it is necessary for them to produce. Thus the bears, and 
seals, and whales, from which the Esquimaux and the Green¬ 
lander derive their support, have an enormous quantity of 
fat in their massive bodies : this fat is as much esteemed as 
an article of food amongst these people, as it would be thought 
repulsive by the inhabitants of southern climates; and by the 
large quantity of it they consume, they are able to support 
the bitterness of an Arctic winter, without appearing to suffer 
more from the extreme cold than do the residents in more 
temperate climes during their winter. On the other hand, 
the antelopes, deer, and wild cattle, which form a large pro¬ 
portion of the animal food of savage or half-cultivated nations 
inhabiting tropical regions, possess very little fat ; and the 
comparatively small supply of carbon and hydrogen, of which 
the combustion is required to keep up the bodily temperature 
of the inhabitants of those regions, is derived from the flesh of 
these animals, in the manner that will be presently explained. 
158. The application of the substances forming the albu¬ 
minous group, to the support of the animal body, by affording 
the materials for the nutrition and re-formation of its tissues, 
needs little explanation. The proportions of the four ingre¬ 
dients of which they are all composed, are so nearly the same, 
that no essential difference appears to exist among them; and 
it is a matter of little consequence, except as far as the gra¬ 
tification of the palate is concerned, whether we feed upon 
the flesh of animals (syntonin, § 16), upon the white of egg 
(albumen, § 13), the curd of milk (casein, § 15), the grain of 
wheat (gluten), or the seed of the pea (legumin). All these 
