838 EESPIKATION 



by bacteria which enter the body through the blood or 

 food; but it is evident that the air furnishes a natural 

 highway for them, and this is another reason why we 

 should make sure that our air supply is as pure as possible, 

 and that we keep our respiratory organs in a healthy state, 

 in order that the germs which enter may be removed before 

 they have time to form colonies. 



Alcohol and respiration. — It is often claimed that alco- 

 hol increases the rate of respiration, and is thus a valuable 

 element in cases where great demands for oxygen are made 

 by the tissues, as in heavy muscular exertions. Careful 

 experiment has shown that alcohol does increase the rate 

 of respiration and the amount of oxygen taken into the 

 body for a period of an hour or more after its use; while 

 highly flavored wines and brandies have an even greater 

 effect in this direction than pure alcohol. "When, however, 

 the manner in which alcohol causes this increase in oxygen 

 supply is investigated, it is seen to be a harmful rather than 

 a helpful agent. The reason for this may be stated as 

 follows : 



Alcohol causes a congestion of the surface blood vessels 

 and a consequent loss of heat to the body. It also causes 

 temporary increase in the activity of the digestive tissues 

 and the muscles. This loss of heat and action of the tissues 

 creates a demand for more oxygen on the part of the body, 

 and this demand acts upon the respiratory center and 

 makes the rate of breathing faster, in order to furnish the 

 increase in oxygen. In other words, if it were not for the 

 action of the alcohol on the tissues there would be no in- 

 crease in the breathing rate, and the increase in oxygen 

 thus secured is more than used up in offsetting the loss of 

 heat and in supplying the needs of these unnaturally active 



