MOISTURE IN THE ATMOSPHERE 19 



by the heating apparatus rapidly yield a supply of moisture. Evap- 

 oration is greatly facilitated by placing the water or wicks in the 

 current of heated air entering the room. By a suitable construction, 

 the water may be replenished automatically. In very cold, dry 

 weather the air supply of an ordinary medium-sized house requires 

 the addition of not less than ten gallons of moisture every twenty- 

 four hours, and sometimes much more. 



How We Take Cold. Constant colds and sore throats testify 

 to the effects on the skin and mucous membrane of too high a 

 temperature and too dry an air. Anaemia, debility, and irritability 

 bear witness to the ill effect of this form of heat on the blood and 

 nerves. Too often the occupants of overheated houses think this 

 is the way to be comfortable. 



The prime cause of colds or chills is not exposure to cold, but 

 to the overheated, confined air of rooms, factories, and public 

 meeting places. Colds and sore throats are the results, not of cold 

 air, but of infection. If the mucous membrane is healthy, the 

 lining of the nose and throat is pale pink, stretches taut over the 

 surface it covers, and protects from infection. Ill- ventilated street 

 cars as well as poorly ventilated, dry houses often may be blamed 

 for many of our colds. 



A steady supply of pure air should be admitted at all times to 

 every occupied room. A piece of board about 8 inches wide and 

 long enough to fit on the bottom sash of a window, in each room, 

 will allow air to enter and rise toward the ceiling if the window is 

 open a little way at the bottom. The air coming in from outdoors 

 will gradually descend on the occupants, who will thus feel no 

 draft. Contact with fresh, cold air does not cause chills or colds. 

 It stimulates activity of both the mind and the body. Careful 

 experiments have shown that for each degree above 65 the power 

 of mental concentration diminishes. This fact is important for 

 those who are working in offices, factories, shops, and schools. 



QUESTIONS 



1. Why does the air feel so chilly in the spring when snow and 

 ice are melting? 



2. What would be the difference between the bodily feeling on 



