28 INSANITY IN THE LOWER ANIMALS. 



4. To separate mania from other comparatively transient 

 conditions which resemble it. 



5. To avoid the confusion of real with spurious hydro- 

 - phobia; or of hydrophobia, whether real or spurious, with 



other diseases, such as hysteria, delirium tremens, and phre- 

 nitis. 



6. To distinguish between hysteria especially cataleptic 

 hysteria chorea, and insanity. 



7. To beware of confounding the mere sulkiness and lazi- 

 ness of the schoolboy, his indifference to, or disinclination for, 

 lessons, his refusal to learn or execute a task, with actual 

 mental incapacity or inability, the result of organic disease 

 of the brain, of congenital defect, or of acquired insanity, a 

 mistake sometimes fatal occasionally committed both by 

 teachers and parents. 



8. To avoid in general terms confounding mental with 

 other disorders, or to distinguish the affections with which 

 insanity may be confounded. 



9. To distinguish between certain premonitions, forms and 

 causes of insanity, as well as between exciting and predispos- 

 ing causes, for instance, in such cases as intense emotion or 

 excitement. 



10. To determine the boundary line between sanity and 

 insanity, one which it is simply impossible to establish. 



There is frequent confusion of causes with results or 

 effects. Thus emotion may be a cause, form or premonitory 

 symptom of insanity, according to its nature, intensity, 

 duration and sequence. The same may be said of mental 

 excitement. It is difficult to tell when or where it passes 

 into mania, to determine the kind or degree that constitutes 

 disease. Eccentricity again may be premonitory of, or 

 amount to, insanity, or it may not be referable to the cate- 

 gory of disease at all. 



If such difficulties occur in man, in whom aid is to be 

 had from speech and writing, they are not likely to be less 

 among the lower animals, in whom no such aid as a rule is 

 possible. On the whole, however, it cannot be said that 

 there is greater difficulty in the diagnosis of insanity in other 

 animals than in man. In both cases the difficulties are 



