This section is from the book "Animal Physiology: The Structure And Functions Of The Human Body", by John Cleland. Also available from Amazon: Animal Physiology, the Structure and Functions of the Human Body.
The Pancreas is a large lobulated gland, about eight inches long and one inch and a half broad, not unlike the salivary glands in appearance, and sometimes called by the Germans the abdominal salivary gland; its secretion, however, is much more important. The pancreatic juice, which is a viscid alkaline fluid containing an albuminoid principle, has a most powerful action in converting starch into sugar, and has the advantage over saliva, that this action is not prevented by the presence of acid. It has also the property, at the temperature of the body, of making a very complete emulsion, or milky fluid, with oils; that is to say, it resolves them into exceedingly minute globules, which remain separate from one another; and these find their way through the walls of the villi into the absorbent vessels. In rabbits the duct of the pancreas opens into the intestine considerably lower than the bile duct; and in them, as Bernard has observed, there are no oil globules in the absorbent vessels above the level of the pancreatic duct; which shows that the bile is incapable of digesting fats without the pancreatic juice. This fluid has likewise been shown to have a solvent action on albuminoids outside the body; and it is possible, as has been suggested by one observer (Flint) that muscular fibre, disintegrated by the gastric juice, is afterwards completely dissolved by means of the pancreatic. It appears, then, that the pancreatic juice is the principal means of digesting starch and oil, and that it is likewise useful in digesting albuminoids.