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 putrefaction, 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 intestines. The smell' and semi-pubescent 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 consideration, 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 production 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 common 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 spermaeeti whale. In the human-intestines also fatty concretions are sometimes found, called scybsla, 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
