250 DIGESTION. [CHAP. xxv. 



quarters of an inch, lower down. Under such circumstances, fat 

 passes through the small intestine unaltered, and the lacteals are 

 filled with limpid chyle, totally devoid of the white colour. 



The influence of the pancreatic fluid in the formation of the 

 white chyle, by its action upon fatty food, is beautifully illus- 

 trated by Bernard in a very simple experiment upon the rabbit, 

 which we have repeated with results precisely corresponding with 

 those obtained by him. The rabbit is selected for this observation ; 

 because, while the choledoch duct opens into the duodenum just 

 below the pylorus, the pancreatic duct opens as much as sixteen 

 or seventeen inches lower down, so that all that length of intestine 

 receives bile only. A small quantity of melted hog's lard was in- 

 jected into the stomach (the animal having been kept without 

 food for twenty-four hours previously), after which it was let to 

 eat freely of parsley and carrots. After five or six hours, it was 

 killed. Between the openings of the two ducts, the lacteals 

 contained a clear limpid fluid; but below the pancreatic duct, the 

 lacteals were turgid with a rich white creamy chyle. 



In confirmation of these results of experiments, it may be stated, 

 that patients labouring under disease of the pancreas, invariably 

 suffer from extreme emaciation, and many cases are recorded in 

 which fat appeared unaltered in the stools, apparently in conse- 

 quence of malignant disease in the pancreas. Cases of this kind 

 are recorded by Elliotson, Bright, and others. 



From the preceding facts, so well collected by the industry and 

 acuteness of Bernard, it seems to us that we must conclude that 

 the principal function of the pancreatic fluid is to digest fatty 

 matters, that is, to reduce them to a state which will admit of 

 their ready absorption by the lacteals. This power is mainly due 

 to the organic principle resembling albumen, which is held in solu- 

 tion in the pancreatic fluid. 



An objection to this view arises from the fact, that some animals 

 have no fat, or oily matter, in their food ; as, for example, many 

 vegetable feeders. This objection, however, may be thus met; that 

 nearly all vegetable substances contain a certain proportion of oily 

 matter, however small ; and, moreover, the pancreatic fluid might 

 serve to digest the fatty matters of the bile, which, by absorption 

 into the lacteals, are readily carried to the lungs for combustion. 



But that the digestion of fat food is not the only office of the 

 pancreas iu digestion, is sufficiently proved by the experiments of 

 Bouchardat and Sandras, already referred to, which point out the 

 important share it takes in the digestion of amylaceous matters. 



