OTHER IMPORTANT FACTS ABOUT AIR 



139 



stances of disobedience and inattention might also 

 have been prevented. 



When we come from out-of-doors into a room where 

 the temperature is too high, the uncom- 

 fortable state of the air is readily noticed. 

 The occupants of the room, however, hav- 

 ing gradually become accustomed to the 

 warm atmosphere, are not aware of its con- 

 dition. It would be a fine thing to equip 

 schoolrooms and other assembling places 

 with alarm thermometers. If such a ther- 

 mometer would give notice of the harmful 

 condition of the air so vigorously that im- 

 mediate attention would be given to cool- 

 ing it, much benefit might result. 



Some people have an idea that if the air 

 of a room is cold, it must necessarily be 

 fit for breathing. For this reason, no win- 

 dows are opened in their unheated sleeping 

 rooms in cold weather. While some air 

 will come through walls and windows when 

 the atmosphere outside is cold enough to have good 

 ventilation, there should be some openings through 

 which the breathed-out air may escape and the pure 

 air come in freely. We should remember that to 

 have our breathing supply pure, a free circulation 

 of air is necessary, and should arrange for it intelli- 

 gently in both winter and summer. 



Any one can easily be convinced of the truth of this 



Thermometer. 



