440 FRAGMENTS OF SCIENCE. 



that every thought or feeling has its physical correla- 

 tive in that organ; and nothing can be more certain 

 than that every physical change, whether molecular 

 or mechanical, requires time for its accomplishment. 

 So that, besides the interval of transmission, a still fur- 

 ther time is necessary for the brain to put itself in 

 order for its molecules to take up the motions or posi- 

 tions necessary to the completion of consciousness. 

 Helmholtz considers that one-tenth of a second is de- 

 manded for this purpose. Thus, in the case of the 

 whale above supposed, we have first half a second con- 

 sumed in the transmission of the intelligence through 

 the sensor nerves to the head, one-tenth of a second 

 consumed by the brain in completing the arrangements 

 necessary to consciousness, and, if the velocity of trans- 

 mission through the motor be the same as that through 

 the sensor nerves, half a second in sending a command 

 to the tail to defend itself. Thus one second and a 

 tenth would elapse before an impression made upon its 

 caudal nerves could be responded to by a whale forty 

 feet long. 



Now, it is quite conceivable that an injury might 

 be inflicted so rapidly that within the time required by 

 the brain to complete the arrangements necessary to 

 consciousness, its power of arrangement might be de- 

 stroyed. In such a case, though the injury might be 

 of a nature to cause death, this would occur without 

 pain. Death in this case would be simply the sudden 

 negation of life, without any intervention of conscious- 

 ness whatever. 



The time required for a rifle-bullet to pass clean 

 through a man's head may be roughly estimated at a 

 thousandth of a second. Here, therefore, we should 

 have no room for sensation, and death would be pain- 

 less. But there are other actions which far transcend 



