CHAPTER X 



VENTILATION, HEAT, AND CLOTHING 



168. Need of fresh air. Since oxygen is taken from 

 the air and carbonic acid gas goes out in its place, the 

 air in a short time becomes unfit for use unless it is 

 changed. Carbonic acid gas is but slightly poisonous in 

 itself, or else the body would always be poisoned, but 

 when it is breathed into the air the same amount of 

 oxygen has been taken away from the air. Only a little 

 oxygen can be taken away from the air before the body 

 feels the loss. In a church, the windows are sometimes 

 closed tightly and but little new oxygen can get in to take 

 the place of that which is breathed. So there is not 

 enough oxygen to keep up the full oxidation within our 

 bodies. As a result, their power is lessened, and we 

 become so sleepy that the best sermon does not keep us 

 awake. 



169. Foul air. Water is always evaporating from ihe 

 nose and mouth and going out by the breath. Odors from 

 the mouth and clothes also enter the air. The moisture 

 and odors are very unpleasant to sensitive persons and 

 may of themselves cause sickness. Disease germs, such 

 as those of measles and smallpox, are often given off by 

 unclean persons. They are no more poisonous in a close 

 room than out of doors, but in a room they are not scat- 

 tered by the wind, and so another person is far more likely 

 to breathe them in than he would be in the open air. So a 



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