VENTILATION OF SLEEPING ROOMS 



411 



Ventilation of sleeping rooms. Sleeping in badly ventilated 

 rooms is frequently the cause of much discomfort and often of 

 illness. Windows should be open top and bottom, but no direct 

 draft should be allowed. 

 This ventilation may 

 often be managed with 

 the use of screens. 



In cities especially, 

 the night air is purer 

 than day air, because the 

 factories have stopped 

 work, the dust has 

 settled, and fewer people 

 are on the streets. The 

 old myth of " night air" 

 being injurious has long 



since been exploded, and thousands of people of delicate health, 

 especially those who have weak throats or lungs, are regaining 

 health by sleeping out of doors or with the windows wide open. 

 The only essential in sleeping out of doors is that the body be 

 kept warm and the head be protected from strong drafts. 



Is this a good method of window ventilation? Why? 



Self-Testing Exekcise 

 Ventilation is the (1) of (2) air with 



(3) 



air. From (4) to (5) cubic feet of air are needed in 



a room by every person per hour. Sleeping rooms are best venti- 

 lated by opening the window (6) and (7), but a 



(8) should be avoided. Ventilate the lungs by (9) 



(10). 



PROBLEM VII. WHAT ARE THE ORGANS OF EXCRETION 

 AND HOW DO THEY FUNCTION? 



Laboratory Exercise. The structure of the kidney. Some idea of 

 the internal structure of the kidney of man may be gained by examina- 

 tion of a sheep's kidney. Get the butcher to leave the mass of fat 

 around the kidney. What is the use of this fat? Notice, after re- 

 moving the fat, that the kidney appears to be closely wrapped in a 

 thin coat of connective tissue ; this is called the capsule. 



