SCIENCE AND MAN 369 



ity, "by the motion of his finger in opening a valve or 

 loosening a detent can liberate an amount of mechanical 

 energy almost infinite compared with its exciting cause; 

 so the nerves, acting on the muscles, can unlock an 

 amount of power out of all proportion to the work done 

 by the nerves themselves." The nerves, according to 

 Mayer, pull the trigger, but the gunpowder which they 

 ignite is stored in the muscles. This is the view now 

 universally entertained. 



The quickness of thought has passed into a proverb, 

 and 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 instan- 

 taneously, at all events with the rapidity of electricity. 

 Hence, when Helmholtz, in 1851, affirmed, as the result 

 of experiment, nervous transmission to be a comparatively 

 sluggish process, very few believed him. His experiments 

 may now be made 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 electric- 

 ity 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 electroly- 

 sis 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 



