1-2 



ELEMENTARY BIOLOGY 



breathing'. It is only in comparativolv recent times, therefore, 

 that we lia\e come to reahze what a close connection there 

 is between our breathing habits and breathing conditions, on 



Head C'l; 



^Supply tube 



-M<i>A(*A^~^~ ■ 



Fu;. 6i. Oxvsien inhalator 



This apparatus tor tlie resuscitation of persons overcome by suffocating fumes or gases 

 was developed by the United States Bureau of Mines. It is used with the Schaefer 

 method of artificial respiration, and supplies oxA-gen for about thirty-five minutes, which 

 is usually sufficient to restore normal breathing. (Photograph by United States Bureau 



of Mines) 



the one hand, and our health, happiness, and efficiency, on the 

 otlier. The most important things that have been discovered 

 by tlie new attention to these details are the following : 



I. iHitdoor air is better than indoor air in ever)" way. 



ij. It is better for playing, even in the cold and rain ; suitable 

 clothing will make up for these. 



