Though I have tried to avoid all possible use of technical terms, in the following very abbreviated description of the digestive organs and their processes, their use will be occasionally required.

In order to make the work of digestion as clear as possible without a lengthy description, we will follow the food in its travels through the alimentary canal, explaining the actions of the organs and various digestive juices with which it comes in contact.

After food has been called for by appetite and has gone through the first process of digestion by thorough mastication, it is swallowed and allowed to enter the stomach. Now immediately upon entrance, this food comes in. contact with the gastric juice which is secreted by the peptic glands, and which exudes in tiny drops from the inner surface of the stomach like perspiration from the pores of the skin. Not only the quality but the quantity of this digestive juice furnished depends greatly upon how much food is needed - in other words on how hungry you are at the time the food is eaten. The feeling of hunger, the ability to heartily enjoy the food eaten, is an unmistakable indication that there will be secreted a full supply of these digestive juices, that will be poured forth copiously as the process of eating and digesting continue; and the more intensely the food is enjoyed, the more each morsel is dwelt upon in the act of mastication by the sense of taste in the endeavor to secure its most delicious flavor before swallowing, die more freely does the gastric juice flow, and, naturally, the more perfectly is the work of stomach digestion performed.

The time required for stomach digestion depends greatly upon the character of the food, and upon how carefully the work of mastication has been performed. If the food has been hurriedly bolted it will require much longer than if it had been practically reduced to a liquid before swallowing. The period of digestion has been variously estimated from two to five hours. The stomach, while digestion continues, involuntarily churns and presses the food back and forth within its walls that it may be thoroughly mixed with the gastric juices. Portions of the digested food that are rendered liquid are all the time being absorbed by the stomach during this process. As the gastric juice of the stomach only digests albuminous, muscle making, articles of food, that will readily account for the feeling of increased muscular power which so quickly follows eating when one is tired and much in need of nourishment; and, when mastication has been properly performed, the saliva begins the work of digesting all starchy, heating foods, and undoubtedly some of this is also absorbed by the glands of the stomach, thus also accounting for the feeling of increased warmth that usually follows half an hour or more after a meal.

Of course immediately after a hearty meal the blood is attracted to the stomach in such quantities in its endeavor to supply the gastric juice and do the other work in connection with digestion, that one naturally feels the cold more than usual for a short time, if exposed, but this passes away within half an hour at most after a meal and a feeling of increased warmth is then noticed.

As part of the mass, being digested by the stomach, assumes a condition that indicates the process of stomach digestion has been completed, it is allowed to pass the pylorus and enter the duodenum, which is a part of the small intestines. Here the food comes in contact with two other digestive juices that are poured forth under normal conditions as needed - the bile and pancreatic juices. The bile is alkaline in character; it neutralizes the gastric juice, emulsifies the fats, making them soluble, and it also has antiseptic qualities which act upon the entire intestinal canal. The pancreatic juice is similar to the saliva of the mouth and performs important offices, though in addition to digesting starchy elements it also digests albuminous - muscle making - and fat.

From the duodenum the food enters the principal part of the small intestines. Here it comes in contact with another fluid called the intestinal juice. This juice possesses the power pecular to itself of digesting all the various food elements, thus practically completing the work of digestion. The small intestines are supplied with a very large number of glands which absorb large quantities of the nourishment made ready by the various digestive juices with which the food had previously come in contact. From the small intestines the food is slowly forced into the colon where absorption still continues though in a much more limited degree.

For a technical description of the process of absorption of the nourishing elements of the food, I refer you to the following by Dr. J. H. Kellogg:

"The process of absorption begins almost as soon as food is taken into the mouth, and continues so long as any soluble nutriment can be extracted from the alimentary mass. The work of absorption is performed by two sets of absorbent vessels, minute veins, and lymphatics, here called lacteals. The venous absorbents take up whatever is held in solution in the food taken into the stomach, and the principal portion of the digested farinaceous, saccharine, and albuminous elements of food. The lacteals absorb the emulsified fats, and some portion of the other elements. The products absorbed by the venous absorbents find their way into the general circulation through the hepatic vein, after passing through the liver, which is apparently a wise arrangement of nature, to provide for a sort of filtration before the more delicate tissues of the body are exposed to the action of whatever deleterious elements the food may happen to contain. It is claimed by physiologists that the liver has also an important function to perform in completing the work of digestion, especially that of starchy substances. The food mingled with venous blood is conveyed to the liver by the portal vein.

Those products which are absorbed by the lacteals, reach the general circulation through the thoracic duct, a long, slender lymph vessel which empties "into the large vein from the arm on the left side."