the side of the stomach, and mingle with the food. The muscular walls of
the stomach contract upon the food, moving it about with a sort of
crushing action, thoroughly mixing the gastric juice with the food.
During this process both the openings of the stomach are closed tightly.
The gastric juice softens the food, digests albumen, and coagulates
milk. The saliva continues its action upon starch for sometime after the
food reaches the stomach.

"After the food has remained in the stomach from one to three hours, or
even longer, if the digestion is slow, or indigestible foods have been
eaten, the contractions of the stomach become so vigorous that the more
fluid portions of the food are squeezed out through the pylorus, the
lower orifice of the stomach, thus escaping into the intestine. The
pylorus does not exercise any sort of intelligence in the selection of
food, as was once supposed. The increasing acidity of the contents of
the stomach causes its muscular walls to contract with increasing
vigor, until finally those portions of the food which may be less
perfectly broken up, but which the stomach has been unable to digest,
are forced through the pylorus.

"_Intestinal Digestion._--As it leaves the stomach, the partially
digested mass of food is intensely acid, from the large quantity of
gastric juices which it contains. Intestinal digestion cannot begin
until the food becomes alkaline. The alkaline bile neutralizes the
gastric juice, and renders the digesting mass slightly alkaline. The
bile also acts upon the fatty elements of the food, converting them into
an emulsion. The pancreatic juice converts the starch into grape-sugar,
even acting upon raw starch. It also digest fats and albumem. The
intestinal juice continues the work begun by the other digestive fluids,
and, in addition, digests cane-sugar, converting it into grape-sugar.