406 CRILE— BRAIN CELLS AND FUNCTIONS. [April i8, 



cases of insanity as phases of a disease, of an injury, or of an emo- 

 tion. The stage of excitation in anesthesia is insanity. The only 

 difference between what is conventionally called insanity and the 

 fleeting insanity of the sick and the injured is that of time. We may 

 conclude, therefore, what must be the brain picture of the person 

 who is permanently insane. This a priori reasoning is all that is 

 possible, since the study of the brain in the insane has thus far been 

 wholly on the brains of those who have died of some disease. And 

 it is impossible to say which changes have been produced by the fatal 

 disease, and which by the condition producing insanity. The only 

 logical way of investigating the physical basis of insanity would be 

 to make use of the very rare opportunity of studying accidental 

 death in the insane. 



Our experiments have proved conclusively that whether we call 

 a person fatigued or diseased, the brain cells undergo physical de- 

 terioration, accompanied by loss of mental power. Even to the 

 minutest detail we can show a direct relationship between the phys- 

 ical state of the brain cells and the mental power of the individual, — 

 that is, the physical power of a person goes pari passu with his 

 mental power. Indeed, it is impossible to conceive how any mental 

 action, however subtle, can occur without a corresponding change 

 in the nerve cells. It is possible now to measure only the evidences 

 of gross and violent mental activity on the brain cells. At some 

 future time it will doubtless be possible to so refine the technique 

 that more subtle changes may similarly be measured. Nevertheless, 

 with the means at our disposal we have shown already that in all 

 these conditions the cells of the cortex showed the greatest changes ; 

 and that loss of the higher mental functions accompanied the cell 

 deterioration. 



Cleveland, Ohio, 

 April, 1913. 



