THE NEED OF FRESH AIR 183 



drowning, or from a severe electric shock. In any one of the 

 above cases, the person's Hfe may be saved by prompt recourse to 

 artificial respiration. The Schaefer method is considered the best 

 and should be given as follows : Place the patient face downward, 

 taking care to keep the mouth and nose free from dirt. Kneel 

 astride the patient at his knees and slowly but strongly press 

 down and forward with the hands immediately over the lower 

 part of the chest cavity, and arms straight. Keep this pressure 

 for about three seconds and then swing your body off suddenly, 

 thus allowing the lungs to fill with air. After two seconds repeat 

 the pressure as before. Count the seconds as you do this so as 

 to time the total respiration movements at twelve to a minute. 

 Why? 



Do not give up work if the patient shows no signs of recovery. 

 Persons who have been for some time under water have been re- 

 suscitated after from four to five hours work. Prompt and regular 

 effort is the thing that counts. 



The Need of Fresh Air. — We are all aware of the discomfort 

 that comes in the crowded auditorium or schoolroom at the end of 

 a school period. Some people think that this discomfort is caused 

 by lack of oxygen in the air or by the presence of too much carbon 

 dioxide. But experiments conducted by the New York State 

 Ventilation Commission and in many laboratories have shown that 

 this discomfort comes largely from two sources, the rise in tempera- 

 ture and the increase in humidity in the air. The source of this 

 heat and moisture is largely the bodies cf the people who are in the 

 room. The death of the unfortunates in the " Black Hole of 

 Calcutta," which in the past was thought to be due to lack of 

 oxygen, was probably caused by heat stroke, due to the increased 

 moisture and rise in temperature from so many bodies packed into 

 the small room. 



Need of Ventilation. — In order to get rid of excess moisture, 

 reduce the heat, and remove the other products of respiration 

 from the air, ventilation is necessary. Ventilation is defined as 

 adequate replacement of used air with fresh air. In addition, air 

 in buildings contains dust, with its load of bacteria, odors of various 

 kinds, and sometimes poisonous gases. 



While natural ventilation, or the exchange of inside air and out- 



