300 THE FAT. 



is resumed. This is not the case with parts distended by fat, 

 although it is when oil is poured into the common cellular mem- 

 brane after death. 6 



The intestines occasionally discharge fat; sometimes solid, 

 sometimes fluid, but concreting quickly on cooling. I have 

 seen such cases, and published a full history of the subject two 

 years ago. f 



" The glands which some celebrated characters have con- 

 tended secrete the fat, are only imaginary, e 



" Whatever may be the truth of this matter, the deposition 

 and absorption of the fat take place with great rapidity. 



" The use of the fat is multifarious. 



" It lubricates the solids and facilitates their movements ; pre- 

 vents excessive sensibility; and, by equally distending the skin, 

 contributes to beauty." It probably supports mechanically, 

 and lessens shocks ; and preserves the temperature of the body, 

 like an inner garment. 



" We pass over the particular uses of fat in certain parts, v. c. 

 of the marrow of the bones. 



" During health, it contributes little or nothing to nourish- 

 ment." h But as soon as food or chyle is deficient, or great eva- 

 cuations occur, it is absorbed, in order to afford as much nourish- 

 ment as possible. 



Fourcroy fancied " that it affords a receptacle for the super- 



Medical Observations and Inquiries, vol. ii. p. 33. sqq. 



Med. Chir. Trans, vol. xviii. I give cases of its discharge from both bowels 

 and urinary bladder : and one of its discharge from the intestines, while the 

 kidneys were discharging sugar and the lungs pus. Ambergris is a fatty matter 

 found in the intestines of the spermaceti whale, but never higher than six or seven 

 feet from the anus. Its quantity has exceeded a hundred pounds, and, though so 

 frequently discharged as to be found on the shore and floating on the waves, ac- 

 cumulation, or the state which occasions it, sometimes appears to destroy life. 

 It is more abundant in proportion as the animal is costive and sickly. 1. c. 



Some birds nourish their young with an oily substance, secreted in their own 

 stomachs. This is so copious in the petrel, that, ^in the Faro Isles, people use 

 petrels for candles, merely passing a wick through the body from the mouth to 

 the rump. Pennant, Brit* Zool. vol. ii. p. 434. 



e " The singular opinion of the distinguished Home, respecting the origin and 

 use of the fat, viz. that it is formed in the large intestines, chiefly by the instru- 

 mentality of the bile, and that it supplies a kind of secondary nourishment to the 

 body, will be found fully described in the Phil. Trans. IS] 3. p. 146." 



h " P. Lyonet conjectures, with probability, that insects destitute of blood 

 derive their chief nourishment from the fat in which they abound. Tr. anat. de 

 la Chenille gui ronge le bois de Souk, pp. 428. 483, sq. and the Preface, p. xiii." 



