336 PRESENT STATE OF ORGANIC ELECTRICITY. 



cord from an induction-coil (in which each primary current 

 induces an opposite in the other wire), the needle returns to 

 zero. 



These experiments appear to prove that when a nerve is 

 completely excited or tetanised by electricity, its usual electro- 

 motor power is diminished or in abeyance ; and as a similar 

 loss of electromotor power also accompanies intense func- 

 tional excitement from ordinary agents, Du Bois Eeymond 

 conceives this negative electric condition to be in some man- 

 ner related to the motor or sensory functional power of the 

 nerve.* 



To what is the Polarisation of the Nerve, when in a state 

 of Functional Activity, due ? A nerve is thrown by a current 

 of electricity into an electric condition apparently similar to 

 that in which it is during excitation by its normal stimuli. 

 Is its natural action due, therefore, to electricity? Is its 

 natural electrotonic condition similar to its so-called artificial 

 condition ? Is it induced by an electric current ? Du Bois 

 Reymond's opinions on this subject are guardedly expressed.! 

 He holds the so-called nervous principle and electricity to be 

 similar or alike. A nerve in action is in an induced electro- 

 tonic state ; and exhibits a consequent amount of negative 

 variation of its ordinary electric current. The source of the 

 inducing current is not stated ; but its direction may be con- 

 ceived as resulting, during its influence, from the direction 

 and extent of the rotation which occurs in one or the other of 

 the two dipolar molecules, of which the presumed ordinary 

 peripolar electromotor elements consist, and on which the 

 ordinary current of the nerve depends. The induced current 



* Chap. vii. of the second division of vol. ii. of the Untcrsuchungen. 



f See p. xv. of the preface of the Untersuchungen, in which Du Bois 

 Eeymond states that the electricity in muscle and nerve will probably ulti- 

 mately prove to be not the mere consequence of their organic processes and 

 actions, but the actual source of their activity. 



