230 ROUGH WAYS MADE SMOOTH. 



mental qualities, because insanity must be regarded as a 

 disease of the moral rather than of the mental nature. Its 

 origin may be in the mind, as the origin of mental diseases 

 is in the brain, that is, is in the body ; but the principal 

 manifestations of insanity, those which must guide us in 

 determining its true position, are unquestionably those rela- 

 ting to moral habitudes. Insanity is not always, or at least 

 not always demonstrably hereditary. Esquirol found among 

 1,375 lunatics 337 unquestionable cases of hereditary trans- 

 mission. Guislain and others regard hereditary lunacy as 

 including, roughly, one-fourth of the cases of insanity. 

 Moreau and others hold that the proportion is greater. It 

 appears, however, that mental alienation is not the only form 

 in which the insanity of an ancestor may manifest itself. 

 Dr. Morel gives the following instructive illustration of the 

 ' varied and odd complications occurring in the hereditary 

 transmission of nervous disease.' He attended four brothers 

 belonging to one family. The grandfather of these children 

 had died insane ; their father had never been able to con- 

 tinue long at anything ; their uncle, a ma.n of great intel- 

 lect and a distinguished physician, was noted for his 

 eccentricities. Now these four children, sprung from one 

 stock, presented very different forms of physical disorder. 

 One of them was a maniac, whose wild paroxysms occurred 

 periodically. The disorder of the second was melancholy 

 madness ; he was reduced by his stupor to a merely auto- 

 matic condition. The third was characterised by an extreme 

 irascibility and suicidal disposition. The fourth manifested 

 a strong liking for art ; but he was of a timorous and 

 suspicious nature. This story seems in some degree to give 

 support to the theory that genius and mental aberration are 

 not altogether alien ; that, in fact, 



Great wit to madness nearly is allied, 

 And thin partitions do their bounds divide. 



Of the hereditary transmission of idiotcy we naturally 

 have not the same kind of evidence. Madness often, if 



