256 INTRODUCTION TO GENERAL SCIENCE 



cubic inches of air, eighteen times a minute, from which part 

 of the oxygen is absorbed. All living beings, including the 

 microscopic forms, require oxygen. Even fishes absorb it 

 from the air which is dissolved in the water, and will die in 

 water from which the air has been removed. Plants also 

 breathe, but this absorption of oxygen must not be confused 

 with the work c-f the leaves. 



While we breathe only about thirty cubic inches per breath, 

 this does not nearly represent the capacity of the lungs, which 

 is about three hundred and thirty cubic inches. It is easy to 

 see, then, that in ordinary breathing we do not supply our 

 lungs with fresh air, but merely dilute the vitiated air that is 

 already there. If we wish to be in a healthy condition, we 

 must realize, then, that at several periods during the day we 

 should make an effort to exhale all the air possible from our 

 lungs and then to take a very deep breath, repeating this 

 four or five times. The effect on the health of a person who 

 will do this every few hours, out in the fresh air, is quite 

 marvelous. Part of the advantage of vigorous exercise is 

 due to the fact that we must breathe more deeply when 

 exercising than we do ordinarily. Although some of us are 

 not strong enough to take violent exercise, yet we can all 

 breathe deeply at some period during the day. 



Human beings breathe in two ways. Women breathe 

 from the chest, men from the abdomen. It is probably true 

 that both methods are wrong. The woman exercises the 

 upper part of her lungs, and the man the lower part. It does 

 not tend to produce even development, and both ways leave 

 part of the lungs unaffected. Both ways tend to produce 

 disease of the lungs, since it is only by the vigorous use of all 

 parts of our body that we can maintain our health. Nature 

 always takes away from us what we do not use. The proper 



