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the state of fat is, to a portion of the nutritive matter extracted from the 

 food, a kind of intermediate state, through which it has to pass before it 

 can be assimilated to the animal whose waste it is destined to repair. 

 Animals which live on grain and vegetables, are always fatter than those 

 which live exclusively on flesh. Their fat is consistent and firm, while 

 that of carnivorous animals is almost completely fluid. 



A corpulent man, on having his diet suddenly reduced, sensibly be- 

 comes thinner, in a very short time: the bulk and weight of his body 

 diminish, from the absorption of the fat which supplies the deficient 

 quantity of blood. Adeps may, therefore, be considered as a substance 

 in reserve, by means of which, notwithstanding the small quantity of food 

 and its want of nutritious qualities, Nature finds wherewith to repair the 

 daily waste. 



CIV. The use of adeps is not, as has been stated, on the authority of 

 Macquer, to absorb the acids that are formed in the animal economy; 

 that which is obtained from it, by distillation, (the sebaceous add] is anew 

 product formed by the combination of the atmosphere with the hydro- 

 gen, the carbon, and the small quantity of azote which it contains. The 

 small quantity of this last substance nearly constitutes it a vegetable 

 acid. Fat has a considerable affinity for oxygen, and by combining with 

 it, turns rancid, after remaining some time exposed to the air. It de- 

 prives metallic oxides of a part of their oxygen, and likewise, on being 

 triturated with metallic substances, promotes their oxidizement. In pro- 

 portion as it absorbs oxygen, its density increases : thus oils become 

 concrete by combining with oxygei, and fat acquires a consistence almost 

 equal to that of wax, which is itself a fatty substance highly oxidized. 



Besides the principal use which we have assigned to adeps, and ac- 

 cording to which the cellular system may be looked upon as a vast reser- 

 voir, in which there is deposited a considerable quantity of nutritive and 

 semi-animalized matter, this fluid answers several purposes of secondary 

 ^utility. It preserves the body in i;s natural temperature, being, as well 

 as the tissue of the cells in which it is contained, a very bad conductor of 

 heat. Persons who are excessively corpulent, scarcely feel the most 

 severe cold; animals which inhabit northern climates, besides being 

 clothed in a thick fur, are likewise provided with a considerable quantity 

 of fat. The fishes of the frozen seas, the cetaceous animals which sel- 

 dom go far from the polar regions, all kinds of whales are covered with 

 fat, and have likewise a considerable quantity within their bodies. By 

 its unctuous qualities, fat promotes muscular contraction, the motion of 

 the different organs, the free motion on each other of the different sur- 

 faces; it stretches and supports the skin, fills vacuities, and gives to our 

 limbs those rounded outlines, those elegant and graceful forms peculiar 

 to the female body. Lastly, it envelopes and covers over the extremities 

 of the nerves, diminishes their susceptibility, which is always in an in- 

 verse ratio of the corpulency ; which induced a physician of merit to say, 

 that the nervous tree, planted in the. adipose and cellular substance, suf- 

 fers, when from the collapse and the removal of that tissue, its branches 

 are exposed, in an unprotected state, to the action of external causes, as 

 injurious to them as the rays of the sun to a plant torn from its native 

 soil. It is, in fact, observed that nervous people are exceedingly thin, 

 and have an excessive degree of sensibility. Too much fat, however, is 

 as injurious as too small a quantity of it. I have seen several persons 

 whose obesity was such, that besides being completely incapable of 



