32 SCIENCE OF HOME AND COMMUNITY 



7. Heated air contains the same amount of water that it did 

 when cold. Why is the per cent of humidity so much lower ? 



8. How may ventilation be secured during the night while 

 asleep ? 



REFERENCES 



Barber, First Course in General Science, Henry Holt and Com- 

 pany, New York City. Chap. 6. 



Fisher and Fisk, How to Live, Funk and Wagnalls, New York 

 City. Chap. I. 



