XXI. 

 DEATH BY LIGHTNING. 



J3EOPLE in general imagine, when they think at all 

 JL about the matter, that an impression upon the 

 nerves a blow, for example, or the prick of a pin is 

 felt at the moment it is inflicted. But this is not the case. 

 The seat of sensation being the brain, to it the intelli- 

 gence of any impression made upon the nerves has to be 

 transmitted before this impression can become manifest 

 as consciousness. The transmission, moreover, requires 

 time, and the consequence is, that a wound inflicted on- 

 a portion of the body distant from the brain is more 

 tardily appreciated than one inflicted adjacent to the 

 brain. By an extremely ingenious experimental arrange- 

 ment, Helmholtz has determined the velocity of this 

 nervous transmission, and finds it to be about eighty 

 feet a second, or less than one-thirteenth of the velocity 

 of sound in air. If therefore, a whale forty feet long 

 were wounded in the tail, it would not be conscious of 

 the injury till half a second after the wound had been. 

 inflicted. 1 But this is not the only ingredient in the 

 delay. There can scarcely be a doubt that to every act 

 of consciousness belongs a determinate molecular arrange- 

 ment of the brain that every thought or feeling has- 



1 A most admirable lecture on the velocity of nervous trans- 

 mission has been published by Dr. Du Bois Reymond in the 'Pro- 

 ceedings of the Royal Institution' for 1866, vol. iv. p. 575. 



29 



