SCIKNCE AND MAN. 609 
The quickness of thought has passed into a proverb, arid 
the notion that any measurable time elapsed between the 
infliction of a wound and the feeling of the injury would 
have been rejected as preposterous thirty years ago. 
Nervous impressions, notwithstanding the results of 
Haller, were thought to be transmitted, if not instantane- 
ously, at all events with the rapidity of electricity. Hence, 
when Helmholtz, in 1851, affirmed, as the result of experi- 
ment, nervous transmission to be a comparatively sluggish 
process, very few believed him. His experiments may 
now be mads in the lecture-room. Sound in air moves 
at the rate of 1,100 feet a second; sound in water moves 
at the rate of 5,000 feet a second; light in ether moves at 
the rate of 186,000 miles a second, and electricity in free 
wires moves probably at the same rate. But the nerves 
transmit their messages at the rate of only 70 feet a second, 
a progress which in these quick times might well be 
regarded as inordinately slow. 
Your townsman, Mr. Gore, has produced by electrolysis 
a kind of antimony which exhibits an action strikingly 
analogous to that of nervous propagation. A rod of this 
antimony is in such a molecular condition that when you 
scratch or heat one end of the rod, the disturbance propa- 
gates itself before your eyes to the other end, the onward 
march of the disturbance being announced bv the develop- 
ment of heat and fumes along the line of propagation. In 
some such way the molecules of the nerves are successively 
overthrown; and if Mr. Grore could only devise some means 
of winding up his exhausted antimony, as the nutritive 
blood winds up exhausted nerves, the comparison would be 
complete. The subject may be summed up, as Du Bois- 
Revmond has summed it up, by reference to the case of a 
whale struck by a harpoon in the tail. If the animal 
were 70 feet long, a second would elapse before the disturb- 
ance could reach the brain. But the impression after its 
arrival has to diffuse itself and throw the brain into the 
molecular condition necessary to consciousness. Then, 
and not till then, the command to the tail to defend itself 
is shot through the motor nerves. Another second must 
elapse before the command can reach the tail, so that more 
than two seconds transpire between the infliction of the 
wound and the muscular response of the part wounded. 
The interval required for the kindling of consciousness 
