Pure air is strictly essential to maintain perfect health.  If a person is accustomed to sleeping with the windows open there is but little danger of taking cold winter or summer.  Persons that shut up the windows to keep out the “night air” make a mistake, for at night the only air we breathe is “night air,” and we need good air while asleep as much or even more than at any other time of day.  Ventilation can be accomplished by simply opening the window an inch at the bottom and also at the top, thus letting the pure air in, the bad air going outward at the top.  Close, foul air poisons the blood, brings on disease which often results in death; this poisoning of the blood is only prevented by pure air, which enters the lungs, becomes charged with waste particles, then thrown out, and which are poisoning if taken back again.  It is estimated that a grown person corrupts one gallon of pure air every minute, or twenty-five barrels full in a single night, in breathing alone.

Clothes that have been worn through the day should be changed for fresh or dry ones to sleep in.  Three pints of moisture, filled with the waste of the body, are given off every twenty-four hours, and this is mostly absorbed by the clothing.  Sunlight and exposure to the air purifies the clothing of the poisons which nature is trying to dispose of, and which would otherwise be brought again into contact with the body.

Colds are often taken by extreme cold and heat, and a sudden exposure to cold by passing from a heated room to the cold outside air.  Old and weak persons, especially, should avoid such extreme change.  In passing from warm crowded rooms to the cold air, the mouth should be kept closed, and all the breathing done through the nostrils only, that the cold air may be warmed before it reaches the lungs, or else the sudden change will drive the blood from the surface of the internal organs, often producing congestions.

Dr. B. I. Kendall writes that “the temperature of the body should be evenly and properly maintained to secure perfect health; and to accomplish this purpose requires great care and caution at times.  The human body is, so to speak, the most delicate and intricate piece of machinery that could possibly be conceived of, and to keep this in perfect order requires constant care.  It is a fixed law of nature that every violation thereof shall be punished; and so we find that he who neglects to care for his body by protecting it from sudden changes of weather, or draughts of cold air upon unprotected parts of the body, suffers the penalty by sickness, which may vary according to the exposure and the habits of the person, which affect the result materially; for what would be an easy day’s work for a man who is accustomed to hard labor, would be sufficient to excite the circulation to such an extent in a person unaccustomed to work, that only slight exposure might cause the death of the latter when over-heated in this way; while the same exercise