PRESENT STATE OF ORGANIC ELECTRICITY. 331 



experiment may be made. The forefinger of each hand being 

 dipped into the saline solutions along with the electrodes of 

 the galvanometer, no deflection occurs. But if all the muscles 

 of one arm be strongly and continuously contracted, a current 

 is indicated as passing from the finger to the shoulder in the 

 contracted arm, and in the opposite direction in the relaxed 

 one. It is evident that this current is the result of the dimi- 

 nution of the ordinary general muscular current in the con- 

 tracted arm, and the substitution for it of the closed circuit 

 of the ordinary current of the opposite arm.* 



The Electric Properties of Nerve. The resemblance between 

 many actions of the nervous system and certain electric phe- 

 nomena has frequently impressed physiologists ; but investi- 

 gations of this subject have been so generally mixed up with 

 that of the electricity of muscle, as to lead to no precise 

 result. Matteucci had failed in obtaining any indication of 

 electric currents in nerves ; but, nevertheless, the singular 

 parallelism between the two powers could not be overlooked ; 

 and Faraday has pointed out the importance of such considera- 

 tions in his statements regarding electro-nervous action and 

 reaction. More recently, Du Bois Eeymond has admitted 

 that electricity and the nervous force are at least equivalents. 

 He was the first to derive electric currents from the nerves, 

 and has procured many most remarkable results from his 

 researches on the subject. 



The Electric Condition of a Nerve in the Intervals of Func- 

 tional Activity. By employing a very delicate galvanometer, 

 Du Bois Eeymond has detected the electric current in nerve, 

 and has determined its laws. They are similar to those of 

 the muscular current, having the same relation to the longi- 

 tudinal and transverse sections ; except that as the nerve 

 presents no natural transverse section, the relative conditions 



* The general muscular current and the frog- current are treated of in the 

 first chapter of section iii. of the Untersuchungen. 



