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 coecum is used in Anatomy to denote a tube closed at one 
extremity. 
