Btmospbere, 49 



dwelling is located above the common level the 

 purer will be the air. This rule, however, has 

 its limits, as the oxygen of the air is heavier 

 than the nitrogen, so that the air at very great 

 altitudes has not the same proportion of oxy- 

 gen to nitrogen that it has at a lower level. 

 An analysis that was made some years ago of 

 the air on the west shore of Lake Michigan, 

 especially that section where the bluffs are 

 high, shows that it compares favorably with 

 that of any other portion of the United 

 States. 



In view of the foregoing, it is of the highest 

 importance to the sanitary condition of any 

 city, town, or village that it be not too com- 

 pactly built. If more than a certain number 

 of people occupy a given area, it is absolutely 

 impossible to preserve perfect sanitary condi- 

 tions. And there ought to be a State law, 

 especially for all suburban towns, which are 

 the homes and sleeping places for large num- 

 bers of business men who spend their days in 

 the foul air of the city, stipulating, that the 

 houses shall be not less than a certain distance 

 apart. Oxygen is the great purifier of the 

 blood, and if one does not get enough of it he 

 suffers even though he breathes no impurities. 

 The power to resist the effects of bad air is 

 much greater when one is awake and active 

 than when asleep, and this is why it is more 

 important to sleep in pure air than to be in it 



