402 CRILE— PHYSICAL STATE OF [April i8, 



activity. We found that strychnia, accorchng to the dosage, caused 

 convulsions ending in exhaustion and death ; excitation followed by 

 lassitude ; stimulation without notable after results ; or increased 

 mental tone. The brain cells accurately displayed these physiologic 

 alterations in proportional hyperchromatism in the active stages, and 

 proportional chromatolysis in the stages of reaction. The biologic 

 and therapeutic application of this proof is as obvious as it is 

 important. 



Alcohol in large and repeated dosage caused marked morphologic 

 changes in the brain cells which went as far even as destruction of 

 the cells. Ether, on the other hand, even after five hours of admin- 

 istration, produced no observable destructive changes in the cells. 



The efl^ect of iodoform was peculiarly interesting, as it was the 

 only drug that produced fever. Its observed effect upon the brain 

 cells was that of widespread destruction. 



Infections. — In every observation on dogs and on man pyogenic 

 infections caused definite and demonstrable lesions in certain cells 

 of the nervous system, the changes in the cortex and the cerebellum 

 being most marked. For example, in infections the result of bowel 

 obstruction, in peritonitis, and in osteomyelitis causing death, the 

 real lesion is in the brain cells. The lassitude, diminished mental 

 power, excitability, irritability, restlessness, delirium and uncon- 

 sciousness that may be associated with acute infections, we may rea- 

 sonably conclude are due to physical changes in the brain cells. 



Graves' Disease. — In Graves' disease the brain cells showed 

 marked changes which were apparently the same as those produced 

 by overwork, by the emotions, and by strychnine. In one advanced 

 case it was found that the brain had lost permanently a large number 

 of cells. This is the reason undoubtedly why a severe case of 

 exophthalmic goitre sustains such a permanent loss of brain power. 



Insomnia. — The brains of rabbits which had been kept awake 

 for lOO hours showed precisely the same changes as those showm in 

 physical fatigue, strychnine poisoning and exhaustion from emo- 

 tional stimulation. Eight hours of continuous sleep restored all the 

 cells except those that had been completely exhausted. This will 

 explain the permanent efifect of long-continued insomnia ; — that is, 



