First of all of the important processes of Nature in her work of building-up, repairing and sustaining the human body, are the processes of Nutrition. The processes of Nutrition are those by which the normal condition of life and growth of the living organism is maintained, and which operate in the direction of the living tissues of the body taking up from the blood the nourishing materials or substances required for their repair and the performance of their healthy functions.

You will note the following two facts: (1) That the tissues take up nourishing material or substance in order that they may keep in repair and perform their ^healthy functions-this nourishment is food, and the products of food; and (2) that this nourishment is taken up from the blood. We have here two great facts of physical life, viz.: (a) That the tissues require and take up FOOD; and (b) that this food is obtained from the BLOOD, and the blood only. (By "the tissues" physiologists mean the material and substance of the organs, muscles, etc., composing the physical body.) Now then, the next thing to ascertain (1) how this nourishment gets into the blood; and (2) how it is extracted and taken up from the blood by the tissues.

Let us begin at the beginning. The food of the human being, composed of animal or vegetable substance, is taken into the mouth, where it is broken up into bits so as to be more easily digested a little later on. But in the mouth we also find the first steps or processes of digestion performed. There are located in the mouth six important glands known as the salivary glands; four of these are located under the tongue and jaw, and two in the cheeks in front of the ears. These glands manufacture and give forth through numerous ducts a fluid substance called "saliva," more commonly known as "spittle." Mixing with the food, while the latter is being chewed, the saliva performs the chemical process of converting the .starchy portion of the food into sugar or glucose, and thus performing the first stage of its assimilation into the system. This chemical process is continued as the food passes down the gullet, but practically ceases when the stomach is reached. (In cases of indigestion, it is well to give some little attention to the cells composing these glands, in your general treatment, for it often happens that they are more or less inactive.)

The stomach is the great chemical laboratory of the body, and in it are performed many important chemical processes in the direction of converting the food-mass into the ultimate form of nourishment in which it is taken up by the blood. In the stomach is manufactured, by countless minute glands, that strong digestive fluid known as "the gastric juice." This juice is a very powerful chemical substance wrhich acts as a solvent upon the nitrogenous portions of the food, and also upon the sugar or glucose into which the starches of the food have been converted by the saliva. One of its most active ingredients is that known as pepsin, which is a powerful digestive agent. About one gallon of gastric juice is manufactured by the healthy stomach each twenty-four hours. It is mixed up with the food very thoroughly by a peculiar churning motion of the stomach which tosses and kneads the food-mass so that the gastric juice is well mixed up with every particle of it, and thus able to perform its chemical processes.

If this work of'digestion in the stomach is not performed for any reason, as, for instance, the stomach having been weakened by abuse and over work, or by the placing into it of too much indigestible stuff, then fermentation is apt to result, and the food-mass, instead of being digested properly, is converted into a putrefj^-ing, rotting, yeasty mass, which instead of nourishing the blood practically poisons it. In such cases we have dyspepsia and other diseases resulting from imperfect digestion and assimilation. In such cases the stomach and its glands should be specifically treated by the practitioner, and encouraged to perform their work properly. The stomach, as I have said elsewhere in these lessons, is a very obedient organ-something like a big, gentle, intelligent Newfoundland dog so far as its mentality is concerned. By proper treatment it may be encouraged to resume normal and natural functioning; but the patient should be told to treat it properly in return. In treating the stomach, address yourself not only to it in itself, but also to the glands manufacturing the gastric juice-it is astonishing how these glands will respond to an earnest appeal, and will manufacture a sufficient amount of gastric juice with a sufficient amount of pepsin in it to do the wrork properly. Treatment of this kind just before a meal will often give the patient a keen appetite, and will result in perfect digestion of that meal. The experiment is most interesting and instructive.

After the food-mass has been treated by and in the stomach as I have just described, it is passed on and out of the stomach on the right-hand side, and enters into what is known as the Small Intestine. The Small Intestine is a long tube, entrail or gut, which is from twenty to thirty feet in length, but which is so ingeniously coiled upon itself as to occupy but a comparatively small space in the body-this intestine must not be confused with the Colon or large intestine which carries away the refuse or garbage of the system to be discharged from the body. The Small Intestine is an important part of the main organs of nutrition. Its surface is lined with a velvety substance which brushes against the food-mass which passes along it, and acts to absorb the fluid food-substance when properly digested.

When the food-mass enters the Small Intestine it is met with a strong, peculiar fluid called Bile, which becomes thoroughly mixed up with it and wrorked into it. The Bile is manufactured by the Liver to the extent of about two quarts a day, and is stored up for future use in what is called the Gail-Bladder. There is also poured into the food in this stage another strong fluid, called the Pancreatic Juice, which is manufactured to the extent of about one and one-half pints daily by the Pancreas, or "sweetbread," an organ situated just behind the stomach. The work of the Bile and the Pancreatic Juice is to act upon the fatty portions of the food-mass so as to render it capable of being absorbed into the blood; the Bile also acts to prevent decomposition and putrefaction of the food as it passes through the intestine, and also to neutralize the gastric juice which has already performed its work and is no longer needed by the system.

In cases of digestive trouble, the practitioner should always treat the Small Intestine, the Pancreas, and the Liver. The first two organs are, like the stomach, quite receptive and responsive to mental treatment-in fact, they are rather more gentle than even that organ, and rather resemble the intelligent well-bred hunting-dog in their mental character. The Liver, on the contrary, as I have said before, is stubborn, rather stupid, and "heavy" in its mentality -it is like the pig or the mule, and must be treated vigorously, firmly, and positively, and emphatically told that it must get to work properly and efficiently.

The food-mass in the Small Intestine is a soft, semi-liquid substance produced by the process of digestion of the food originally taken into the mouth. It reaches the Small Intestine from the stomach in the form of a pasty substance called Chyme. This Chyme is transformed by the intestinal juices and Bile into three derivative substances, namely: (1) Peptone, derived from the digestion of albuminous substances; (2) Chyle, derived from the emulsion of the fatty substances; and (3) Glucose, derived from the transformation of the starchy substances. It should be noted, however, that the fluids taken into the stomach as drink, as well as the fluids liberated from the solids in the process of digestion in the stomach, do not reach the Small Intestine at all-instead, they are rapidly taken up by the absorbent apparatus of the stomach and carried into the blood, and thence to the kidneys and bladder^ and finally voided from the system in the urine. Some of the fluids, of course, are retained in the body to perform necessary work therein.

The work of absorption of the digested food substances, or nourishment, from the Small Intestine into the blood is performed by the millions of plush-like "hairs" of the velvety inner surface of the Small Intestine, which maintain a constant waving motion through the semi-liquid digested food contained therein, and "lick up" and absorb the nourishment now fitted for the system. In this way the Peptone and Glucose are carried into the blood to the Liver, and then passed through the heart as you shall learn in a later lesson. The Chyle is absorbed by the lymphatic vessels called "the lacteals," and thence to the thoracic dnct, and then gradually conveyed to the blood.

In a subsequent lesson I shall take up the story of the assimilation of the food from this point, and show you the processes whereby the blood carries this nourishment to all parts of the body, nourishing cells and tissue, organs and parts, building-up and repairing each. To many it seems a strange idea that the blood is the carrier and distributor of this nourishment derived from the food-but it is a scientific fact nevertheless.

In another subsequent lesson I shall take up the subject of the elimination of the waste products which remain after the nourishment is extracted from the food by the processes of digestion.

Before passing on, however, I wish to impress upon the minds of students and practitioners the fact that in most cases of chronic ailments the original cause of the trouble is to be found in these main organs of nutrition. If the body is not sufficiently nourished, or if it be furnished with improper material, it is bound to rebel and manifest in the form of abnormal function or disease. No matter what may be the superficial symptoms, it will always be well to take these organs into account, and to give them the proper treatment. In fact, many of the best practitioners, before proceeding to more local treatment, give a strong, thorough, preliminary treatment both to the main organs of nutrition and the organs of elimination. If the body is properly nourished, and its waste products are properly carried off, the liability of disease is materially lessened, and the work of cure rendered materially easier and simpler.

The body has often been compared to a piece of intricate machinery, which is rim by the steam of the vital force. This steam is generated by the fires of the furnace of the organs of nutrition; and these fires must be kept well supplied with the nourishment of the proper kind of food, and fanned by the draft of perfect functioning. Also, the ashes and clinkers must not be allowed to accumulate-the wrork of the organs of elimination must be kept normal, and up to the mark.

Hence, student and practitioners, keep these two main points always before you-attend well to the organs of nutrition, and those of elimination, and nine-tenths of your work is accomplished. For, from imperfect digestion and assimilation, and imperfect elimination, arise a veritable swarm of diseases, symptoms, and physical troubles.