ABSORPTION FROM THE DIGESTIVE CAVITY. 509 



ing the solution of the various azotized principles, and in regard to them, 

 therefore, it is injurious; but it seems, from the observations of Dr. Beaumont, 

 to be a spontaneous occurrence, whenever the diet has been for a long time, 

 and in great part, of an oleaginous nature ; and it then appears destined to aid 

 in the reducing process, which is the proper function of the stomach. It is 

 suggested by Dr. A. Combe, whether the peculiar digestibility of a piece of 

 fat bacon, in certain forms of Dyspepsia, may not be due to the abnormal 

 presence of bile in the stomach. The power of precipitating the proteine- 

 compounds from their acid solutions, which has been shown, by the recent 

 experiments of Plainer, to belong to the peculiar principles of bile, fully ex- 

 plains its injurious effects upon the solvent processes, which normally take 

 place in the stomach. In regard to the Albuminous and Gelatinous articles 

 of food, there is no evidence that any other change is effected in them, than 

 one of simple solution ; and they appear to be absorbed in the same condition 

 as that to which they are reduced by the action of the stomach. 



CHAPTER XI. 



OF ABSORPTION AND SANGUIFICATION. 



I. Absorption from the Digestive Cavity. 



672. So long as the Alimentary matter is contained in the digestive cavity, 

 it is as far from being conducive to the nutrition of the system, as if it were in 

 contact with the external surface. It is only when absorbed into the vessels, 

 and carried by the circulating current into the remote portions of the body, 

 that it becomes capable of being appropriated by its various tissues and organs. 

 Among the Invertebrata, we find the reception of alimentary matter into the 

 Circulating system to be entirely accomplished through the medium of the 

 blood-vessels, which are distributed upon the walls of the digestive cavity. 

 But in the Vertebrata, we find an additional set of vessels interposed between 

 the walls of the intestine and the sanguiferous system; for the purpose, as it 

 would seem, of taking up that portion of the nutritive matter which is not in 

 a state of perfect solution, and of preparing it for being introduced into the 

 current of the blood. These are the lacteals, or absorbents of the intestinal 

 walls. That their special office is to take up the product of the admixture of 

 the chyme with the biliary and pancreatic fluids, appears from the fact, that 

 they are not distributed at all upon the walls of the stomach, nor upon those of 

 the duodenum above the point of entrance of the hepatic and pancreatic ducts; 

 but that they are copiously distributed upon the walls of the remainder of the 

 small intestine, and more sparingly upon those of the large. Each lacteal 

 tube originates in the interior of one of the villous processes of the mucous 

 membrane lining the intestinal tube. The accompanying figure represents the 

 appearance offered by the incipient lacteals, in a villus of the jejunum of a 

 young man, who had been hung soon after taking a full meal of farinaceous 

 food. The trunk that issues from the villus is formed by the confluence of 



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