tly minute to permit of
their being absorbed into the blood.

Again, this most important digestive fluid produces on starch an action
similar to that of saliva, but much more powerful. During its short stay
in the mouth, very little starch is changed into sugar, and in the
stomach, as we have seen, the action of the saliva is arrested. Now, the
pancreatic juice takes up the work in the small intestine and changes the
greater part of the starch into sugar. Nor is this all, for it also acts
powerfully upon the proteids not acted upon in the stomach, and changes
them into peptones that do not differ materially from those resulting from
gastric digestion. The remarkable power which the pancreatic juice
possesses of acting on all the food-stuffs appears to be due mainly to the
presence of a specific element or ferment, known as _trypsin_.

Experiment 60. _To show the action of pancreatic juice upon oils or
fats._ Put two grains of Fairchild's extract of pancreas into a
four-ounce bottle. Add half a teaspoonful of warm water, and shake well
for a few minutes; then add a tablespoonful of cod liver oil; shake
vigorously.

A creamy, opaque mixture of the oil and water, called an emulsion, will
result. This will gradually separate upon standing, the pancreatic
extract settling in the water at the bottom. When shaken it will again
form an emulsion.

Experiment 61. _To show the action of pancreatic juice on starch_.
Put two tablespoonfuls of _smooth_ starch paste into a goblet, and while
still so warm as just to be borne by the mouth, stir into it two grains
of the extract of pancreas. The starch paste will rapidly become
thinner, and gradually change into soluble starch, in a perfectly fluid
solution. Within a few minutes some of the starch is converted through
intermediary stages into maltose. Use the Fehling test for sugar.

152. Digestion in the Small Intestines. After digestion in the
stomach has been going on for some time, successive portions of the
semi-digested food begin to pass into the duodenum. The pancreas now takes
on new activity, and a copious flow of pancreatic juice is poured along
its duct into the intestines. As the food is pushed along over the common
opening of the bile and pancreatic ducts, a great quantity of bile from
this reservoir, the gall bladder, is poured into the intestines. These two
digestive fluids are now mixed with the chyme, and act upon it in the
remarkabl