How to Keep Well 



467 



Air Supply. Air is the first requisite of life. Without it, 

 even with plenty of water and food, adequate light, and suit- 

 able temperature, we can live only a very short time. You have 

 undoubtedly noticed that it is impossible to hold your breath long 

 without great discomfort. Unless you resume breathing you will 

 soon become unconscious. Your blood will lose its bright red 

 color and death will quickly ensue. 



National Tuberculosis Association. 



FRESH AIR Is THE FIRST REQUISITE IN THE CURE OF TUBERCULOSIS 



Good ventilation requires an adequate amount of fresh air 

 continually kept in motion and having a proper degree of humid- 

 ity. The widespread use of sleeping porches, and roof play- 

 grounds in crowded cities, and the efforts to secure as much 

 outdoor life as possible, mark one phase of the world movement 

 for the prevention of disease. 



Water Supply. The fact that water makes up more 

 than one-half the weight of our bodies, and that we are con- 

 stantly drinking it to replace that which has been excreted, 



