CHAP. XVIII. 



THE FAT. 



IN many parts of the body a fluid exists, which must be con- 

 sidered before we close our account of the production, application, 

 and purification of the blood or, in other words, of the natural 

 functions. The fat, in truth, nourishes the body, when food can- 

 not be procured or cannot be assimilated. 



" The fat* is" a yellow " oily fluid, very similar in its general 

 character to vegetable oils b , bland, inodorous, lighter than water; 

 containing" oleine, stearine, glycerine, and margaric and oleic 

 acids substances, together with some others, found in the fatty 

 secretions of different animals. Stearine is the solid principle, 

 and oleine the fluid principle, of oils. It consists ultimately of 

 carbon, oxygen, and hydrogen. * 



Carbon - 79-000 



Oxygen - 9-584- 



Hydrogen - 11-416 



" When secreted from the blood and deposited in the mucous 

 tela, it exists in the form of drops, divided by the laminae of the 

 tela, in a manner not unlike that in which the vitreous humour of 

 the eye is contained in very similar cells. 



" The relation of fat to different parts is various. 



" In the first place, some parts, even those whose mucous tela 

 is extremely soft and delicate, never contain fat. Such are the 

 palpebrae and penis. 



" In very many parts, it is diffused indefinitely, especially in 

 the panniculus adiposus, the interstices of the muscles, &c. 



" In some few, it is always found, and appears to be contained 

 in certain definite spaces, and destined for particular purposes. 

 Such we consider the fat around the basis of the heart c : and in 



* " W. Xav. Jansen, Pinguedinis Animalis Consideratio Physiologica et Patho- 

 logica. Lugd. Bat. 1784. 8vo." 



b " J. D. Brandis, Comm. (rewarded with the royal prize) de oleor. ungui- 

 nosor. natura. Getting. 1785. 4to. p. 13.'* 



c " Hence it is clear how many exceptions must be made to the assertion of 



