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AIR

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Pacific Press Publishing Company · Oakland, California · Jan 11, 1899

FromSigns of the Times, Vol. 25, No. 2.

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AIR.

By John Harvey Kellogg

THE first inquiry suggested to the thinking mind would be, What is it? and what is its office?
It is the elastic fluid that we breathe. It surrounds the earth to a distance of about fifty miles above the surface, and forms what is called the atmosphere. It can not be seen, but can be felt. This is demonstrated by moving the hand back and forth rapidly through the air. The Creator stated that it “bloweth where it listeth, thou hearest the sound thereof, but canst not tell whence it cometh, and whither it goeth.”
It is a gas, odorless and colorless, consisting of twenty-one parts of oxygen and seventy-nine parts of nitrogen, of which oxygen is the most important, for if deprived of this we can live but a few minutes. It is the first essential to all life, the highest and richest blessing to man. Without it a fire will not burn, and all life will cease to exist. Steel and iron can be burned in pure oxygen, also the waste material in our bodies, which are poison factories. The nitrogen in the air dilutes the oxygen to the proper consistency, so that it can be used by the body to the best advantage.
The air tends to stop motion. This we call resistance, and can be illustrated by dropping a penny and a feather and noticing which reaches the ground first.
Air exists in every substance, and is impenetrable, as is shown by inverting a cup or other small vessel in water and forcing it down. The upper part of the cup will be found without water in it; the air has kept the water out. The compressibility and elasticity of air are also illustrated by this same experiment; as the water compresses the air in the cup and enters part way into the cup, and as the cup is brought nearer the surface, the air again expands and fills the cup. One hundred cubic inches of air weigh thirty-one grains, which makes it eight hundred and fifteen times lighter than water. Its density at the sea level is fifteen pounds to the square inch. This can be more fully appreciated when we remember that the area of our body is about two thousand square inches, which would make us stand under the enormous load of thirty thousand pounds. The reason that we are not crushed under this pressure is because it is counter-balanced by an equal pressure from within.
As we ascend from the earth the air becomes more rare. This is the reason that in climbing a steep mountain it is more difficult to breathe, at great heights even causing the blood to ooze from the nose and ears, the veins to swell, extremities to become cold, and the head to ache. Heat also brings about the same condition.
Air is also a non-conductor of heat. When air is oppressively warm, and no breeze is stirring, we are overcome by the heat, because the air does not carry off the heat generated in our bodies. Set the air in motion by use of a fan and we are soon relieved.
CALIFORNIA SCENERY, No. 1.—A view in Yosemite Valley. Washington Tower on the right and Half Dome on the left, reflected in Merced River. A fuller description of this wonderfully beautiful valley will be given later.
CALIFORNIA SCENERY, No. 1.—A view in Yosemite Valley. Washington Tower on the right and Half Dome on the left, reflected in Merced River. A fuller description of this wonderfully beautiful valley will be given later.
How do we obtain this vital fluid? It is a gift of our Creator. He gives it to us in its pure state, but we bar it out by the use of walls and tents, and therefore perish—by a fire of our own kindling. How often we stop by the little hut or hovel, and see an opening called a door; possibly in the door we discover a small window! If the air is cool, these will be closed, at the same time shutting out the pure air, that which sustains life. To appreciate this, take a candle into such a house and see how soon it grows dim and then goes out. This shows the condition of the air; and what it did for the candle it will, slowly but surely, do to our lives. Impure air in a room may also be detected by the sense of smell. If one enters a room, coming in out of the pure air, and detects a disagreeable odor, it is in all probability due to the fact that the room has not been properly ventilated. When we have ascertained that the air in a room is in an unhealthy condition, it is our duty to see that it is supplied with fresh, pure air which God has so bountifully supplied to us without money and without price.
How may we obtain pure air in our dwellings?—There are two points to be remembered, First, hot air always rises. Second, cold air always falls. This accounts for the current of air in a room when we open a door or window—the cold air rushes in and the warm rushes out. The opening should, if possible, be on the opposite sides of the house or room; thus our efforts are supplemented by the pressure of the air without. As each person in a room requires three thousand cubic feet of air per hour, we should be very careful to have our rooms so ventilated as to supply this amount of fresh air to each individual. The air in a room being the same temperature, the foul air, being heavier, would naturally fall to the floor; if we admit cold, fresh air, it would naturally fall to the floor, displacing the foul air, and as it became heated, it would gradually rise, crowding the foul air before it. If the fresh air is heated, it rises at once and rolls along the ceiling; as it cools, it settles, and, as the foul air is ahead of it, the outlet should be near the floor.
The amount of fresh air is determined as follows: Air heated to 40° Fahr. above the outside air travels at the rate of 5 feet per second. The outlet should be large enough so the foul air can escape faster than the pure air comes in. It is estimated that we can figure the velocity at 10 feet per second. Then, as it requires 3,000 cubic feet of air per hour for each individual in a room, divide the amount required by the velocity and the result will be the area of the opening required. For example, if two persons require 6,000 cubic feet of air for one hour, they will require 1 2/3 feet per second; this divided by the velocity, 10, would leave 1 2/3 feet, the area of the opening required or 2 persons; 40 per cent. in air ducts is usually added to the above for obstruction of register plate. H. F. RAND, M.D.