BEST AND SLEEP 277 



from such a practice, loss of strength and vitality is 

 quite likely to come if it is continued. It is far wiser 

 and more economical, in the long run, to exceed rather 

 than to cut short the sleeping hours ordinarily consid- 

 ered necessary. When we feel ill or nervous, it may 

 even happen that quietly resting in bed a few hours 

 or days will completely restore our strength. 



Certain conditions help the body to gain the greatest 

 possible benefit from sleep. The first is a plentiful 

 supply of pure, cool air. One may sleep all night with 

 windows closed, because of wintry atmosphere outside, 

 and yet feel languid and nervous in the morning. 

 This is because the large amount of carbonic acid gas 

 in the room during the latter part of the night has 

 had a depressing effect. A person may not wake 

 once through a hot summer's night, and still not be 

 rested next day, for, even with wide-open windows, 

 there may not have been sufficient circulation of air to 

 keep the atmosphere pure and bracing. A sleeping- 

 room having two or more windows should always be 

 preferred to a chamber with but one, as good ventila- 

 tion is much more easily secured, especially in summer. 



Then there should be just enough bed clothing to 

 keep the body comfortably warm. An unnecessarily 

 heavy covering is too warm, and does not afford suffi- 

 cient chance for air to circulate near the skin. Usually 

 it is well to sleep with the head on a low pillow. A 

 firm, compact mattress is also more hygienic than the 

 feather and straw ticks that were formerly in com- 



