462 



On the Formation of Fat in the Intestines of living Animals. By Sir 

 Everard Home, Bart. Presented by the Society for promoting the 

 Knowledge of Animal Chemistry. Read March 18, 1813. [Phil. 

 Trans. 1813, p. 146.] 



In the course of the author's inquiries respecting the digestive 

 organs of different animals, he has been gradually led to suppose that 

 the office of the colon and lower intestines in general is different from 

 that of the upper. In the stomach and small intestines the process 

 of forming and separating the chyle is carried on ; but after the food 

 has passed into the caecum and colon, it appears to undergo a total 

 change in its appearance and smell, with some tendency to putrefac- 

 tion, that is not observable in the contents of the small intestines, 

 and is prevented from being communicated to them by a valve that 

 does not allow even gases to pass upwards into the small intestines. 



The general construction also of the colon and caeca favours the 

 opinion that the functions which they perform are of a different kind ; 

 since their capacity and arrangement would occasion the passage of 

 their contents to be more tardy than it is through the small intes- 

 tines. The smell and semi-putrescent state of these matters led to 

 a comparison of them with animal substances buried in the ground 

 in moist situations, which are known to be converted into adipocere, 

 and suggested the possibility that the secondary digestive operation 

 performed in the lower intestines might be the formation of fat; and 

 this conjecture appeared to the author to be supported by the con- 

 sideration, that fat is the winter supply in dormant animals, and that 

 these animals have a formation of intestines peculiar to themselves, 

 in which there is no valve to distinguish the beginning of the colon, 

 and no other impediment to the free supply of materials for the pro- 

 duction of fat. 



The author next adduces an instance of the conversion of a corpse 

 into adipocere (in the course of twenty-one years) in Shoreditch 

 churchyard; and compares the situation of feculent matters retained 

 in the cells of the colon with a current of more fluid matters passing 

 over them with that of bodies buried in the neighbourhood of a com- 

 mon sewer; and he enumerates various instances in which substances 

 of a fatty nature are known to be formed in the large intestines. 



Ambergris, for example, is never found excepting in the last seven 

 feet of the intestines of the spermaceti whale. In the human intes- 

 tines also fatty concretions are sometimes found, called scybala, and 

 these have a considerable resemblance to ambergris. 



One instance of the formation of fatty concretions in the intestines 

 appeared to have occurred in consequence of having swallowed large 

 quantities of common olive oil. The consistence of these is com- 

 pared to that of soft wax, and by analysis they appeared to consist 

 of two thirds olive oil, and one third animal mucus. 



A second instance is noticed, which, as well as the preceding, was 

 observed by Dr. Babington in a child 4| years old, subject to 

 jaundice, who has voided for some time past at intervals of ten days 



