194 BILIARY, PANCREATIC, AND INTESTINAL SECRETIONS. 



pancreatic fluid closely corresponds with that of saliva, which 

 it much resembles in appearance. The intestinal juice, like 

 the gastric, is a nearly colourless, somewhat viscid fluid, con- 

 taining an organic compound not far removed from albumen ; 

 but it differs from the gastric juice in being alkaline instead 

 of acid. The relative offices of these three fluids have not 

 yet been determined with certainty ; but there appears good 

 reason to believe : (1) that the bile, by its alkalinity, neutralizes 

 the acidity which the chyme derives from the gastric juice, 

 and that this neutralization favours the metamorphosis of 

 starch into sugar, which has been almost suspended in the 

 stomach ; (2) that the bile aids the pancreatic fluid in re- 

 ducing the oleaginous particles to the condition of an emul- 

 sion, that is, in bringing them into a state of very minute 

 division, in which they remain suspended in the albuminous 

 solution ; (3) that the pancreatic fluid aids the salivary mat- 

 ter which was swallowed with the food, in the transforma- 

 tion of starch into sugar ; (4) that the intestinal juice has a 

 solvent power for albuminous substances which is scarcely 

 inferior to that of the gastric juice, with a power of converting 

 starch into sugar which is scarcely inferior to that of saliva 

 or pancreatic fluid. The fluid of the Small Intestine, com- 

 pounded of the salivary, gastric, intestinal, biliary, and pan- 

 creatic secretions, appears to possess a far greater digestive 

 power than that of the stomach, being capable of dissolving, 

 or at any rate of reducing to an absorbable condition, nutri- 

 tious substances of every class. This process goes on during 

 the passage of the alimentary mass along the small intes- 

 tine ; and the nutritious materials are progressively with- 

 drawn by absorption, partly into the blood-vessels, which 

 appear to receive whatever are in a state of perfect solution 

 ( 218), and partly into the lacteal absorbents, which take up 

 nothing but that peculiar emulsion of albumen and fatty matter 

 which is termed chyle ( 222). 



214. At the extremity of the Small Intestine, there is a 

 kind of pouch, called the coecum ; which in some animals 

 seems almost like a second stomach, and which is furnished 

 with one or more little appendages, termed coeca* This is very 

 small in Man, and does not seem to perform any important 



* The word ccecum is used in Anatomy to denote a tube closed at one 

 extremity. 



