The Influence of Sunshine
By John Harvey Kellogg
SUNSHINE is the mightiest thing in the world. Scientists have advanced the idea that it is really the sunshine that turns the earth; that the impulse of the sun’s rays striking upon the earth is the cause of its rotation upon its axis. At any rate, it is certain that sunshine is the motive power which sets in operation nearly all the forces of life as well as many of the physical processes which are continually going on upon the face of the earth. It is the sunshine that enables the little seed to sprout and germinate in the earth, and send up its stem into the air, and its rootlets into the soil, gathering from the air and the soil the elements out of which it builds its trunk, its flowers, its leaves, and its fruit. The sun shining upon the leaves of the plant sets up a process of digestion similar to that which takes place in the human13stomach—a process by which carbonic acid gas is taken in, and the carbon organized into woody structures, into starch and sugar, and the various elements which compose our foods. If you visit the greenhouse, you will notice that the gardener goes about among the flowers from time to time, moving the plants, and turning them toward the sunlight; you will observe that the plants turn their faces toward the glass, so as to catch as much of the vitalizing influence of the sunshine as possible. The sunflower follows the sun over the arch of heaven all the day long, and catches its last rays at night. Indeed, the behavior of some flowers in reference to the sun is so precise that they constitute a floral clock, and it is possible by looking at the face of the plant to tell exactly what time of day it is. It is the sunshine that paints the flower with scarlet, blue, and various other colors. These colors are simply a few extracts from the sunlight; for the sunbeams have all the colors in them; it is from this source also that the green leaf gets its color. In the same manner the cells of the skin are stimulated by the sunshine to make pigment, or coloring-matter, and thus the skin is said to be “tanned” by exposure to the sunlight. Freckles are caused by an unequal distribution of this coloring-matter, or pigment. This pigment does not come from the wind; it is not painted on, but is manufactured by the living, active cells in the skin, through the action of the sunlight. So the cells which make the muscles, nerves, etc.,—those which make bile in the liver, and in fact all the cells,—have their activity quickened under the influence of sunshine. Just as the little polyp is awakened by the sunshine, so the little cells of the skin and of the rest of the body are awakened by its influence. Another interesting thing about sunshine is that it not only develops and stimulates human life, and animal and vegetable life, but it is destructive of parasitic life. There is one class of plants that do not flourish in sunshine,—the fungi, mushrooms, etc., which grow in the shade; they love the darkness, and grow under leaves, logs, and stones. You have observed that where a large tree overhangs the roof of a house or barn, a great mass of moss and other fungi is very apt to be found growing on the roof in the shadow of the tree. Mildew and mold are found on garments which have been hidden away in a dark room. Molds grow on the damp walls of a dark cellar, and on the under side of a board lying on moist ground. These are parasites which attack to destroy—and there are parasites which attack human beings. All those germs which are fatal to human beings are destroyed by the sunshine. These germs get into the body, where they are hidden from the sunshine, and then attack us; but they can not live in the sunlight. If we spend a large part of the time out of doors, where the sun can shine upon us and through us, the germs can not flourish. The sunshine illuminates our bodies just as the whole hand is illuminated by the electric light. When we stand out in the clear blaze of the sunshine, there is not a corner of the body that is not penetrated by it.