PURE AIR AND THINGS THAT SPOIL IT 7 



cheeks are flushed, though some of them have pale faces 

 instead. Only a few sit up straight, while none of them 

 look as if they enjoyed studying. One class is reciting a 

 spelling lesson, and I notice that several of the children 

 miss the easiest words. In this room the air is wretched. 

 I look around and cannot see any place for fresh air 

 to enter. 



The second room is of the same size, and although it 

 holds the same number of children, still everything here 

 is different. Both the girls and the boys look as if they 

 enjoyed studying, most of them are sitting up straight, 

 their eyes are bright, they do not often miss the easy 

 words, and nobody looks cross. As might be expected, 

 enough fresh air is coming into the room all the time to 

 keep it fresh and pure. 



If you should put very many dogs or other living crea- 

 tures into a room, and then shut every door and window, 

 the animals would use up the air as fast as children do ; 

 and if they could get no more, they would die as those 

 men died in the Black Hole of Calcutta. 



Last summer a ten-year-old friend of mine caught a 

 mouse by the tail and put it under a tumbler. She was 

 afraid it would not get air enough, so she slipped a 

 pencil under one edge of the glass to hold it up and let 

 the air get in. She was so careful of the health of the 

 mouse that it lived merrily, until one day the glass tipped 

 over and it ran away. 



