Between the power which repairs a trifling injury in any part, or that knits a broken bone or heals a serious wound, and the power which previously was occupied in maintenance of the body, there is no difference, and this power is identical with the power of development seen in the embryo. The power of production is the power of reproduction; the power of creation is the power of recreation. The power that produces the body is the power that renews it. The power of generation is the power of regeneration. The power that built the living organism also repairs it. The processes which are constantly active in renewing, repairing, and maintaining the body are identical with those processes which have been used in building the body. The powers of life are within; the power of renewal is within.

This reparative and defensive power, which is nothing more nor less than the ordinary powers of healthy life, never rests day or night, asleep or awake, so long as life lasts, and even, after somatic death has occurred many cells in the body continue, for some time, to repair and defend themselves. This reparative power is inseparable from life and is exercised only by life. It never begins but once--when life begins--and never ends until death. It does not depend upon any special conditions or treatments. The snail only asks for the ordinary or natural conditions of snail life in order to grow a new head. He requires no drugs, serums, salves, antiseptics, vaccines, antitoxins, electrical currents, x-rays, radium, nor any drugless treatment. The celery or parsley stalk needs only the ordinary or natural conditions of plant life in order to grow a new shoot or leaf to take the place of the destroyed one. The same is true of the crab that has lost its claw. Given these conditions, even though not in their perfection, and life is capable of accomplishing all the reparative work possible. What life cannot do, cannot be done by treatment.

4. The power of the living organism to reject and eliminate all waste, useless and injurious substances. The first three powers which we have just considered all depend upon the power peculiar to living things to appropriate dissimilar material from their environment, transform it into matter like themselves, and incorporate it into their own structure. The power to reject and refuse waste, useless and injurious substances and to eliminate these is as fundamental as the power of appropriation and transformation or assimilation. Each of these two powers are equally essential to the continuance of the living state and the living organism equally serves its own end in either set of actions.

The complex animal body is adequately equipped with organs and structures, the function of which is to excrete and eliminate from it all waste matter, toxins etc. Chief among these are the lungs, kidneys, bowels, liver and the mucous surfaces of the hollow organs of the body. No special notice will be given these regions at this place. I desire, however, to direct attention to one phase of the work of keeping the body clean that is frequently overlooked. I refer to the work performed in the nose and throat in filtering the air we breathe and in removing from the air passages dust, etc., that get into these.

These passages are lined with fine hair-like projections called cilia. These are very close together and continually wave to and fro like the stalks of grain in a wheat field. However, the stroke made in one direction is sharp and decisive, the recovery is slower and more gentle, reminding one of the stroke of a whip or an oar or the movements of the hands in swimming. These cilia are overlaid with a thin film of moisture or mucous which is kept moving by their strokes. Any small particles of dust, germs, etc., which adhere to the surface of these passages are carried along with the moving film. In the bronchial tubes the movement is from below upward toward the throat so that dust that might otherwise accumulate in the lungs and result seriously is continually cleared away. It is carried to and gathered temporarily about the root of the tongue where it is usually swallowed but sometimes coughed up and spit out. One physiologist compares us to vacuum cleaners "freeing the air of part of the suspended material and depositing it in our own stomachs." But it is not allowed to remain in the stomach. It passes out with the food and, after traversing the entire length of the digestive tract, is expelled from the bowels.

The nose and trachea filter the air we breathe, warm it and moisten it and thus fit it for entrance into the lungs. The atmosphere is nowhere pure enough and usually not warm and moist enough for man's breathing until it has passed through this process. The air which enters the lungs is as different from that which enters the nostrils as distilled water is different from that which entered the still.

The man with weak or diseased lungs finds it painful to breathe through his mouth but experiences no such difficulty in breathing through his nose. The mouth does not prepare the air for the lungs as does the nose. Some dust does escape the action of the cilia and gets into the lower portions of the air passages where no cilia exists, where it may accumulate and stain the lungs. This is seen in the lungs of coal miners, inhabitants of smoky cities and workers in other dusty places. Further mention of this will be made in the chapter on what is "disease".

Cilia surrounding the edge of the mouth of the sea anemone usually beat from without inward, thus keeping a steady stream of water flowing into the body cavity. However, if a non-nutritive substance, such as a grain of sand, is placed upon the margin of the mouth, the cilia immediately reverse their motion in an effort to expel the foreign particle. Here the power of rejection is manifest.

All orifices of the body are normally self-cleaning. Their secretions are normally antiseptic and so long as their health remains unimpaired, unless overwhelmed from without, they remain clean and clear. A diarrhea soon cleanses the digestive tract when it becomes foul.

The normal undisturbed excretion of waste matter is absolutely essential to life and health and the normal organism is capable of carrying on this process of excretion in an adequate manner so long as the normal conditions of life are present. When these conditions are only imperfectly or partially supplied to the body for a length of time it gradually loses the normal energy of all its functions. The work of excretion is impeded, resulting in an accumulation of toxic matter which is destructive to life and health.

Matter is constantly being formed in the body, or received into it from without, that is both useless and injurious and, if allowed to remain and clog the activities of life, would produce disease or death. If the urine is suppressed for 52 hours, death results; the carbon dioxide exhaled in a day would kill many times over if retained. If a wound is obstructed so that drainage is stopped, septicemia and probably death soon result. There is not a moment of life, from birth to death that the body's processes of purification are not busily engaged in eliminating all wastes and toxins from the system. Closely wrapped up with and inseparable from this power of rejection is the power of the living organism to detoxify, through chemicalization, all waste and toxins that are formed in it as a result of the normal processes of life, or all organic poisons that gain an entrance into it from without. This detoxifying work is accomplished largely in the liver and lymphatic glands or nodes including, also, such lyphoid structures as the tonsils, adenoids (which are also tonsils), pyers patches in the small intestines, and the Vermiform appendix.