WORK AND WASTE. THE BLOOD. f>l 



5. Few people die of old age. Generally, before the 

 time for such a death is reached, some disease attacks the 

 enfeebled body, and overcomes it. 



6. The process of repair is going on all the time: but, 

 during our waking-hours, waste is greater than repair; 

 hence, every one. must sleep several hours in each twenty- 

 four. During sleep, the waste is very small; and the pro- 

 cess of repair restores to the system eax'h night what it has 

 lost during the day. 



7. The need of sleep is indicated by a feeling of fatigue 

 and drowsiness. These are the warnings that Nature 

 gives us to stop for repairs. Without this feeling, we 

 would not be willing to lie inactive for so much of each 

 day. Since rest is very important, this feeling is made 

 so strong that it is almost impossible to resist it. Ex- 

 hausted men will fall asleep on horseback, or even 

 walking. 



8. But Nature gives her warning in good time. If it is 

 necessary to continue working for a while after we begin 

 to feel tired, we can generally do so without injury; but 

 we must rest afterward. However tired we may be at 

 night, if we are rested by our night's sleep we are safe ; 

 but if the wear of the day is not fully repaired, and we 

 feel each morning more weary than on the morning be- 

 fore, we are in danger. 



9. A very young infant sleeps most of the time. He 

 requires less sleep as he grows older. Grown persons 

 need from six to nine hours sleep every day. Indolent 

 people often take too much. On the other hand, it is 

 easy to injure the health, particularly in early life, by 

 taking hours which belong to sleep for work or pleasure 

 This is especially injurious when the weary body and 



