BRAIN TROUBLES. 283 



learn that where a slight lapse of memory is noticed, 

 the indication may be taken as a sign that rest is 

 needed. But there are, as we have seen, other ways 

 in which this special power may come to be affected; 

 so that if the memory should show signs of failure 

 where we have no reason to believe that overwork has 

 caused the mischief, we may infer that some one or 

 other of the causes which, as we have seen, may affect 

 the memory seriously have operated injuriously in 

 slight degree. Nor in general need we be in much 

 doubt as to the true nature of the cause, simply because 

 we cannot fail (usually) to recognise in the circum- 

 stances preceding the attack the origin of the mischief. 

 Thus, although a serious failure of the memory con- 

 sidered apart from the circumstances preceding it 

 might leave the physician in doubt whether depletion 

 or plethora (to mention two possible causes) had 

 produced the mischief, yet the physician, apart even 

 from an examination of the patient's condition, could 

 learn at once from him whether either of these two 

 opposite conditions had existed before the attack. In 

 like manner, any person whose memory suddenly 

 seemed weakened could, as his own physician, ascer- 

 tain (unless, indeed, his memory failed to remind him 

 how he had passed the hours or days preceding the 

 attack) whether the mischief resulted from deficiency 

 or excess in the amount of food or stimulants he had 

 previously taken, whether the proper remedy would 

 be, on the one hand, some such medicine as a glass of 

 wine and a chop, or, on the other hand, a diminution 



