238 RULES FOR THE PROPER EXERCISE 



will be sleepless for hours after going to bed, or 

 perhaps be tormented by unpleasant dreams. If, 

 notwithstanding, the practice be continued, the 

 want of refreshing repose will ultimately induce a 

 state of morbid irritability of the nervous system, 

 not far distant from insanity. It is therefore of 

 great advantage to engage in severer studies early 

 in the day, and devote the two or three hours which 

 precede bedtime to lighter reading, music, or amus- 

 ing conversation. The vascular excitement pre- 

 viously induced in the head by study has then time 

 to subside, and sound refreshing sleep is much more 

 certainly obtained. This rule is of great conse- 

 quence to those who are obliged to undergo much 

 mental labour. 



There are, no doubt, individuals so happily consti- 

 tuted, and whose natural sphere is so essentially 

 that of activity, that they are able to think and work, 

 early and late, for years in succession, with very 

 little sleep, and with little regard to diet and regi- 

 men ; but they are so obviously exceptions to the 

 general rule, that we cannot for a moment hold them 

 up as models for imitation; and even they would 

 enjoy their astonishing gifts with greater security, 

 were they to conform more completely with the 

 laws of their organization. 



Periodicity, or the tendency to resume the same 

 mode of action at stated times, is peculiarly the 

 characteristic of the nervous system ; and, on this 

 account, regularity is of great consequence in exer 

 cising the moral and intellectual powers. All ner- 

 vous diseases have a marked tendency to observe 

 regular periods, and the natural inclination to sleep 

 at the approach of night is but another instance of 

 the same fact. It is this principle of our nature 

 which promotes the formation of what are called 

 habits. If we repeat any kind of mental effort every 

 day at the same hour, we at last find ourselves enter- 

 ing upon it, without premeditation, when the time 



