CITY AIR. 253 



the less carbonic acid will be exhaled; 

 and thus country people will inhale pure 

 oxygen, instead of air impregnated with the 

 narcotic poison, called carbonic acid gas. 



Q. Why do TREES and FLOWERS help to make 

 country AIR WHOLESOME ? 



A. Because trees and flowers absorb 

 the carbonic acid generated by the lungs 

 of animals, putrid substances, and other 

 noxious exhalations. 



Q. Why is the AIE of CITIES LESS wholesome 

 than COUNTRY air ? 



A. 1st Because there are more 

 inhabitants to vitiate the air : 



2ndly The sewers, drains, bins, and 

 filth of a city, very greatly vitiate the air : 



3rdly The streets and alleys prevent 

 a free circulation : and 



4thly Besides all this, there are fewer 

 trees to absorb the excess of carbonic 

 acid gas, and restore the equilibrium. 



Q. Why are PERSONS who live in CLOSE 

 BOOMS and crowded CITIES, generally SICKLY ? 



A. Because the air they breathe is 

 not pure, but is both defective in oxygen, 

 and impregnated with carbonic acid gas. 



