BEAIN TEOUBLES. 295 



liave been saved from furfclier weakening. So, remem- 

 bering how close in reality is the analogy between the 

 mental and bodily powers, we can well believe Dr. 

 Forbes Win slow, when he tells us that when the 

 attempt to fix and concentrate thet noughts requires 

 a continuous, painful, and vigorous effort of the will, 

 "serious and irreparable injury may be done to the 

 delicate organisation of the brain and mind by inju- 

 dicious attempts to exercise, stimulate, and force into 

 activity the morbidly nagging and sluggish mental 

 faculties/' These symptoms show that the brain is 

 for the time being unfit for sustained action or for 

 intense action, though not necessarily (or even pro- 

 bably) diseased, and that rest is essential to restore 

 its enfeebled energies. Whether such rest should be 

 long-continued or not, will depend upon the question 

 whether the symptoms of weakened powers of atten- 

 tion are marked or otherwise, and also in no slight 

 degree on the length of time during which these 

 symptoms, whatever they may be, have been neg- 

 lected. If they are attended to so soon as they are 

 noticed (in which case they will probably be slight), a 

 very brief rest will generally restore to the mind its 

 wonted energies. Many a man, who in the midst of 

 prolonged and arduous mental exertion, has noticed 

 signs of flagging in his power of attention, has found 

 in even half an hour of sound sleep a remedy more 

 effective than a three months' rest would be after such 

 signs had been neglected during several successive 

 weeks of mental labour. 



