88 



the omentum guards the intestines against cold, and preserves in them a 

 gentle warmth, necessary to digestion ; or shall we admit the opinion ot" 

 those who maintain, that it answers the purpose of a fluid, filling up 

 spaces, and lessening the effect of friction and pressure from the anterior 

 parietes of the abdomen ; or shall we assert with others, that the use of 

 the omentum is to allow the blood to flow into it, when the stomach, in 

 a state of contraction, is incapable of receiving it. May not the^blood 

 which flows so slowly in its long and slender vessels, acquire some olea- 

 ginous quality which renders it filter to supply the materials of bile*? 



The stomach likewise stretches, though in a less distinct manner, 

 towards its lesser curvature, and the laminse of the gastro-hepatic 

 omentum are separated from each other, as those of the omentum 

 majus. ^ Such is the utility of the gastro-hepatic omentum, which may 

 be considered as a necessary result of the manner in which the peritoneum 

 is disposed in relation to the viscera of the abdomen. This membrane, 

 which extends from the stomach to the liver, so as to cover it, could not 

 fill the space which separates those organs, were it not for a kind of 

 membranous communication which connects them, ami in which are con- 

 tained the vessels and nerves, which, fro pi the lesser curvature, or the 

 posterior edge of the stomach, course towards the concave surface of the 

 liver. This gastro-hepatic epiploon, may besides, by the separation of 

 the t\Vo laminae of which it is formed, favour the dilation of the hepatic 

 vein, which is situated, as well as the vessels, the nerves, and the excre- 

 tory ducts of the liver, in the thickness of its right border. 



The stomach has ever been considered as the principal organ of diges- 

 tion, yet its function in that process is but secondary and preparatory; it 

 is not in the stomach that the principal and most essential phenomenon 

 of digestion takes place, I mean the separation of the nutritive from the 

 excrementitious part of the food. The food, when received into the 

 stomach, is prepared for this separation which is soon to be performed, 

 it becomes fluid, and undergoes a material alteration ; it is converted into 

 a soft and homogeneous paste, known under the name of chyme. What 

 is the agent that brings about this change? or in other words, in what 

 does digestion in the stomach consist? 



As it is frequently necessary to clear a spot on which one means to 

 build, we will bring forward and refute the hypotheses that have been 

 successively broached, to explain the mechanism of digestion. They 

 may be enumerated as follows : concoction, fermentation, putrefaction, 

 trituration, and maceration of the food taken into the cavity of the 

 stomach. 



XV. The first of these opinions was that of the ancients and of the fa- 

 ther of physic ; but, by the term concoction, Hippocrates did not mean 

 a phenomenon similar to that which takes place, when food is put into a 

 vessel, and exposed to the influence of heat. The temperature of the 



* The omentum seems to lubricate the intestines by means of its adipose halitus, 

 and to aid in facilitating the continual movements of the intestines. It also appears to 

 assist in the reciprocal motion which takes place between the digestive tube and the 

 anterior abdominal parietes, especially in preventing the natural and increased action 

 of the latter, during respiration and muscular exertion, from impeding or injuring the 

 function of the former. It likewise obviates the adhesion of the intestines to the peri- 

 toneum during disease, and the consequent impediment to the operations of the 

 primse vise. Copland. 



