Lessons from Common Things

Lessons from Common Things By President F. S. Harris of the Brigham Young University 2. AIR THE earth with its 200 million square miles of surface is sur- rounded by a comparatively thin layer of gases, ordinarily regarded ,as about fifty miles in thickness. The density of these gases even at sea level is not great, and by the time the highest mountain is reached they are becoming still more rare. Half of the atmosphere is contained in the lower three and one-half miles. This mixture of gases, the air, is composed largely of inert nitrogen, although it has a large proportion of oxygen, together with minor quantities of carbon dioxide, water vapor and a number of rare gases. All of us have spent our entire lives bathed in this fluid atmosphere. None of us has at any time lived without being completely surrounded with it. We are never conscious of it except when the wind blows or there arises some unusual situation such as lack of oxygen or excess of carbon dioxide in a mine or a poorly ventilated room. Let us spend a few minutes looking into this very common substance to see some of the various ways it affects our lives. First, as to its composition, the nitrogen of the air enters into every living cell. No cell, either animal or plant, could exist without the nitrogen which forms part of its protein. The nitrogen in the air is inert, or lazy in reacting with other chemical elements. Through the action of bacteria and other agencies, however, sub- stances are produced from this nitrogen which are active. Plants, and, later, animals eagerly utilize this active nitrogen to help form their tissues. Nitrogen is especially abundant in such products as flesh, eggs, and the solid part of milk, although it is also found in all living things. There is not sufficient nitrogen stored up in the earth to serve as food of plants and animals for more than a very short time. It requires the constant activity of the nitrogen-gathering agencies to keep enough of this gas locked in the available form to keep plants and animals growing vigorously. Another interesting gas formed in air is carbon dioxide. This is present in only small quantities — a fraction of a per cent of the total air. It is sometimes spoken of as poisonous carbon dioxide, but this property merely refers to its action on animals when the gas becomes too concentrated. If it were not for the presence of this gas in the air, it would be impossible for plants to live and function.

292 IMPROVEMENT ERA Feb., 19Z9 It is the carbon dioxide of the air, combined with the water from the soil, which produces the bulk of food for both plants and animals. If, in making the air, this carbon dioxide had been by chance left out of the mixture, plants could not manufacture their food, and with- out plant food animals could not live, so the earth would be destitute of life. Probably most of us are more aware of the presence of the element oxygen in the air than of the other constituents. We are constantly being told that we must make sure we have enough oxygen to breathe; teachers and health officials warn us to sleep with the bedroom window open, to watch the ventilation in crowded rooms and other places where oxygen is scarce or rapidly used. Oxygen is just as indispensable to our lives as the other main atmospheric gases, but not more so. There is a constant demand for oxygen to unite with the food we eat, and thereby furnish energy. It is also important because of its ability to combine with fuels of various kinds to give heat, not only for use within our own bodies but also for warming houses, and heating steam and air to run engines. If the atmosphere were entirely made of oxygen, life could not exist because the burning process would be so rapid that life would be consumed; without oxygen the burning process necessary to animal life would cease. Another interesting matter concerns the quantity of atmosphere. If, in the making of a world such as ours, there had been a lesser amount of air, then the higher sections of the earth would have been useless for living organisms. As it is, with the possible exception of one or two mountain tops, there seems to be just about enough air to support vigorous life on all parts of the earth. The mixture of the gases, as well as the quantities, just about balances the demand. There has not been any great waste in the gases; there is enough to satisfy life and to absorb and check the loss of heat from the earth, but none which could well be spared. Do combinations of such circumstances as a perfect atmosphere come by accident? Did it just accidentally happen that the mix- ture of gases surrounding the earth is just what it should be to create harmony? Could so wonderful a balance in weight, com- bining qualities, reaction to heat and cold, and power to move where it is most needed by man, just come about without any intelligent planning? The reader may answer these questions for himself in the way he sees fit. "No man has come to true greatness who has not felt in some degree that his life belongs to his race, and that what God gives him he gives him for man- kind."— Phillips Brooks.