VENTILATION 121 



breathing organs send along with it many particles 

 of fetid matter which have a noxious smell and may 

 also contain disease germs. Not only does this unclean 

 watery vapor pass from the lungs, but the pores of 

 the skin are also continually giving it out. 



When we go into a poorly ventilated room contain- 

 ing a number of people, the disagreeable odor noticed 

 is not carbonic acid gas, though much of it may be 

 present, for that is odorless. It is the smell from the 

 fetid matter in the watery vapor breathed out by the 

 people in the room. If this could be seen, we certainly 

 should take much greater care to have a good circu- 

 lation of air in dwelling and assembly rooms. It is 

 unquestionably true that facts learned in physiology 

 lessons and emphasized only now and then, through 

 the sense of smell, do not make the same impression 

 as something visible. 



People who are too particular to drink from the 

 same cup or glass others have used, often sit in close 

 rooms breathing in foul air that they and others have 

 breathed out, without any thought about its lack of 

 cleanliness or the numerous disease germs it may 

 contain. Without the slightest concern, they breathe 

 in noxious particles of tissue that have been expelled 

 from the breathing organs of others. Any irritation 

 of the throat or lungs, cold, headache, or other dis- 

 agreeable feeling, naturally resulting from breathing 

 impure air, is usually charged to cold air. An effort 

 may be made to remember when and where they were 



