The Harvester World: Volume 6, number 2, February 1915

              Welfare Work

PROTECTION     AGAINST    INJURY SANITATION HEALTH
INDUSTRIAL    EDUCATION RECREATION SPORTS

Fresh Air

Do you know the big, able-bodied man who begins to cough as if he had suddenly been seized by a des¬ perate attack of croup, if you open your window in the car when the air is suffocating and foul enough to make you "dopey" for the rest of the morning? Have you caught his bullying glances which are meant to con¬ vince you that you are risking his life?
Do you know the anaemic office man who draws up his coat collar and sits in a dejected heap when some one opens a window in the otHce and he can feel the stagnant air moving away to make place for a fresh supply? It is moving air that he is afraid of, not the stagnant air that contains not only his own exhalations but those of many other persons.
Do you know the girl who wears summer underwear, and a decollete lingerie or chiffon waist all winter, and who sniffs and sputters at any one who dares to open a window in a room where she and perhaps ten or more other persons will spend seven or more hours breathing each others' exhalations?
They are all pitiable and amusing, these three, fight¬ ing against fresh air without which they cannot hope to be healthy, and making a determined stand for the very thing that will gradually but surely reduce their own vitality.
Because there are these three and more like them, we are reprinting the articles on ventilation taken from Dr. W. A. Evans' column in the Chicago Tribune.
INSPIRATORY EXPERIMENTS Copyright:   1914:   By Dr. W. A. Evans
In a recent set of experiments Dr. Thomas Crowder of the Pullman company undertook to discover how much of the air taken in at one inspiration is the air breathed out with the next preceding expiration. The results of his experiments show us at least a part of the reason one feels better in the morning after a night's sleep in the open air.
That one does feel better thousands testify to. Fur¬ thermore, the testimony goes to show that the nearer one comes to sleeping entirely in the open the better he feels. Sleeping in a room with the windows open is good, but it falls a little short of the maximum.
Thousands of persons have testified to these facts, as they were established by the sense of well-being. About the only way of measuring the effects of ventilation is by the feel of those affected. Starting with this as a fact, men have tried to find the reason.
That was not the object of Dr. Crowder's search, but his observations bear on the question. His observa¬ tions showed that under about average still air condi¬ tions a little over 2 per cent of the inspired air is air that has just been expired.
In a small bedroom on a windy day, when the tem¬ perature of the room was 42, a comparison was made between the reinspiration when the window was down and when it was raised about a foot, allowing the air in the room to be changed about sixteen times an hour. The difference was one-half of 1 per cent in favor of the slightly open window condition.
When the experimenter stood directly in a current of air from the inlet to the outlet there was no reinspira¬ tion.
In another experiment, when he stood in a current of air moving at the rate of 120 feet a minute, no air was rebreathed. When he stood in this same well ventilated room but to one side of the air current there was 6 per cent of reinspiration.
With an electric fan blowing air over the face no air was reinspired. When he was walking around the room or standing over a radiator no air was reinspired.
When he was lying flat in bed reinspiration was less than when he was in the sitting posture. Sleeping on a pillow increased the reinspiration, especially if the pil¬ low was a soft one. Lying on the side with the face in a soft pillow materially increased the reinspiration.
Air currents playing over the face with enough force to be felt as a breeze were not sufficient to drive the expired air entirely away from the pit in the pillow.
Crowder found that sleeping in tents, houses, and half-open porches did not wholly prevent reinspiration. On a sleeping porch with two open, but screened sides, when the temperature of the outside air was 70 and a breeze was blowing at the rate of 400 feet a minute, reinspiration was between one-third and one-half the figure for inside conditions.
ECONOMY IN VENTILATION
A common ventilation requirement is that 3,000 cubic feet of fresh air per hour for each person shall be allowed to enter a room. Some of the older standards required 4,000 feet. The more recent requirement is 2,000 feet. The usual public school standard is 1,800 feet.
The tendency is steadily toward a lower requirement. This is because the underlying principles of ventilation are coming to be applied, not because men are becom¬ ing more indifferent toward good ventilation.
When anything new is undertaken the tendency is to overplay. When information becomes more exact the requirements are lowered in order to prevent risk.
In eight hours a person living in a room containing 1,200 cubic feet of air uses only 6.4 cubic feet of the oxygen in the air and adds to it about the same number of feet of carbonic acid.
A Canadian writer asks: Why bring in 24,000 cubic feet of fresh air to get rid of this twenty feet of expired