226 APPLIED PHYSIOLOGY 



coal stove or a leaking gas pipe may smother a whole family while they 

 are asleep. 



In treating a case of poisoning by gas, an abundance of fresh air 

 should be admitted, and artificial respiration should be performed. 



394. Germs of disease in foul air. Disease germs may 

 be breathed into the air. If the air of a room smells 

 stuffy, it is a hint that the germs as well as the stuffy 

 ddors may be accumulating. Lung diseases are especially 

 frequent among those who work in close rooms. The 

 germs of " colds," scarlet fever, and all other " catching " 

 diseases, are also likely to accumulate in a close room. 

 Sick persons often breathe out the germs of disease, which 

 may reenter the body and continue the disease. More- 

 over, every discomfort retards recovery, so in sick rooms 

 and hospitals a continuous supply of fresh air is especially 

 necessary, while in every room the air should be changed 

 often enough to prevent the stuffy odor from developing. 



395. Consumption. Tuberculosis of the lungs, or consumption, 

 is an infectious disease, caused by the growth of living germs within 

 the lungs. A person suffering with consumption is continually giving 

 off the germs in the secretions from his air passages. His handker- 

 chief contains millions of them. While moist they remain on the 

 handkerchief or clothes, but when dry they may float through the air, 

 and when inhaled may produce the disease. A consumptive is always 

 a menace to other occupants of a room, especially if he does not exercise 

 great care with the secretions from his nose and mouth (p. 392). 



396. Ventilation. Continually replacing the impure air 

 of a room with fresh air is ventilation. Nowadays, with 

 air-tight rooms and closed stoves, openings need to be pro- 

 vided for the exchange of air. When, by breathing, the 

 quantity of carbonic acid gas in the air is increased by one 

 half its natural amount, other substances have also en- 

 tered the air, so that it begins to be stuffy. When the 



