Rural Hygiene

by Henry N. Ogden

Professor Jacob, late Professor of Pathology, Yorkshire College, Leeds, gives the following example on a large scale, to show the results of insufficient ventilation: "A great politician was expected to make an important speech. As there was no room of sufficient dimensions available in the town, a large courtyard, surrounded with buildings, was temporarily roofed over, some space being left under the eaves for ventilation. Long before the appointed time several thousand people assembled, and in due course the meeting began; but before the speaker got well into his subject, there arose from the vast multitude a cry for air, numbers of people were fainting, and every one felt oppressed and well-nigh stifled. It was only after some active persons had climbed on the roof and forcibly torn off the boards for a space about twenty feet square that the business of the meeting could be resumed."

Remembering that the process of breathing is for the purpose of supplying oxygen to the blood and that the absorption of oxygen in the lungs is the same process which goes on when a candle burns, the following experiments were made by Professor King of the University of Wisconsin, to show the effect of expired air on a candle flame. He took a two-quart mason jar and lowered a lighted candle to the bottom, noting that the candle burned with scarcely diminished intensity. Through a rubber tube, he breathed gently into the bottom of the jar, with the result that the candle gradually had a reduced flame and was finally extinguished. He observed also that if the candle were raised as the flame showed signs of going out, the brilliancy of the flame was restored, while lowering the candle tended to extinguish the flame. Even when the candle was raised to the top of the jar, the flame was extinguished after sufficient air had been breathed into the jar. Clearly, then, he argued, air once breathed is not suitable for respiration, unless much diluted with pure air. He argued from this that if a candle using oxygen for combustion could not burn in expired air, therefore an individual using oxygen for the renewal of the blood could not be properly supplied in a room partially saturated with the expired products of the lungs.

Professor King also experimented with a candle burning in a jar on which the cover had been placed, and found that the candle was extinguished in thirty seconds, and he argued that if a candle was thus extinguished on account of the carbonic acid given off, so a person shut up in an air-tight chamber would similarly be extinguished in the course of time.

To prove that expired air is poisonous to animal life, Professor King experimented on a hen, placing the same in a cylindrical metal air-tight chamber eighteen inches in diameter and twenty inches deep. The hen became severely distressed for want of ventilation and died at the end of four hours and seventeen minutes.

In the Wisconsin Agricultural Experimental Station, an experiment was conducted for fourteen days on the effect of ample and deficient ventilation on a herd of cows. The stable was chiefly underground and had two large ventilators which could be opened or closed at will. The food eaten, the water drunk, the milk produced, and weight of the cows were recorded each day. For a part of the time the cows were kept continuously in the stable with all openings closed, and then the ventilators were opened, the alternate conditions being repeated at intervals of four days. The amount of food consumed was practically the same under both conditions. The quantity of milk given was greater with good ventilation. The chief difference was in the amount of water consumed, since with the insufficient ventilation the cows drank on the average 11.4 pounds more water each, daily, and yet lost in weight 10.7 pounds at the end of each two-day period. Examination of the animals themselves also showed that a rash had developed on their bodies which could be felt by the hand and which was apparently very irritating, since it was so rubbed by the animals as to cause the surface to bleed. The evident teaching of the experiment is that under conditions of poor ventilation, it was impossible for the lungs to remove waste products to as great an extent as usual, and, therefore, the demand for additional water was felt in order to stimulate greater action on the part of the kidneys to care for these waste products. That this was not a successful substitute was shown by the loss of weight in the animals, and by the irritation of the skin which evidently was trying to eliminate some of the remaining impurities through its surface.

Modifying circumstances.

Fortunately for mankind, it has not been customary, nor even possible, to build dwellings or stables approaching the air-tightness of a fruit jar. Air has great power of penetration, particularly when in motion, and a wind will blow air through wooden walls, and even through brick walls, in considerable quantity. It is practically impossible to build window casings and door frames so that cracks do not exist, through which air may find its way. When, however, in the wintertime, storm windows have been put on, or when, as occasionally happens, to keep out drafts, strips of paper are pasted carefully around all window casings, or when rubber weather strips are nailed tight against the windows and doors, conditions are obtained which resemble the mason fruit jar, and under those conditions, a person living continuously in such a room is experimenting on himself as Professor King did with the candle.

Another reason why it is difficult to make a room an air-tight chamber is that if a stove or fire-place be in the room, a strong suction is produced through the flame, and such suction requires the entrance of outside air. It is a common experience that a fire-place in a room otherwise tight will refuse to draw and will smoke persistently until a door or window is opened, when, a supply of air being provided, the fire is made bright and active.

Fortunately, the vitiation of the air in a room is never so severe as that in an experimental chamber, and there are few examples which can be cited of men or women dying from lack of ventilation in an ordinary room. But the serious aspect of inadequate ventilation is not that it actually induces death, but that it decreases the powers and activities of the various organs of the body; that it interferes with their normal processes, that it loads up in the body an accumulation of organic matter which is normally oxidized by fresh air and which, if not oxidized, obstructs the activities of other organs of the body.

Danger of polluted air.