PHYSICS OF THE BRAIN. 
427 
gested with blood, and had undergone previous disease. I found 
the anterior cerebral ganglia specially involved, and from the 
whole of this dumb but forcible evidence, I learned that the man 
was insane, that he had been insane before this time, that his 
insanity had taken the impulsive character, and that in a fit of 
extreme and uncontrollable impulse, he had committed suicide 
by throwing himself under the train. When the facts of this 
man’s life were brought out before the coroner, Dr. Lankester, 
they gave the same evidence to the letter, nor less nor more. 
In the heat of battle it is not the cerebrum but the cerebellum 
which propels the man on ; in the chase in the race it is the 
same. The vehement tendency to rush forward, which nearly 
all persons feel when they look over a deep precipice, is of the 
same nature. The cerebral ganglia, overcome by the impression 
made upon them, are, for the moment, deprived of power, and 
the cerebellum, acting with sudden and uncontrolled force, gives 
the initiative propulsive start towards what is sometimes a 
deadly fall. But I must cease. If in the physics of the brain 
I have shown that some things, deeply interesting in their social 
as well as their physiological meanings, are known, what have I 
not unintentionally shadowed forth of that which has yet to be 
discovered, by the bold, the diligent, the truthful disciple of 
nature ? Who shall show how the imagery of the brain is phy- 
sically cast; who shall disclose that imagery as a world to be 
visibly seen ? Yet in the days to come even these things, 
simple as known as wonderful when unknown, shall be revealed. 
