CHAP. XI. NOT AFFECTED D0EIN& NEEVE ACTION. 149 



another time in the inverse direction. Now in 

 whatever manner the nerve was excited to action, 

 I faUed to obtain any evidence of a decided increase 

 in the nerve current, neither could I obtain any 

 definite indication of a sudden decrease in the nerve 

 current; the needle gradually receded. Vibrations 

 of the needle were frequently observed, and were 

 evidently due to the motion of the electrodes caused 

 by the movement of the limb during the contraction 

 of the muscles. The effects upon the needle were 

 just the same, in whatever position the electrodes of 

 the galvanometer were placed ; whether the electrode 

 in contact with the surface of the nerve was placed 

 on the upper or lower portion of the nerve, between 

 the stimulated portion of the nerve and the other 

 electrode, or below the latter. There was no de- 

 cisive action upon the needle in these experiments 

 indicative of any marked influence over the nerve 

 current; the needle merely returned to its former 

 position, or gradually receded. 



When the galvanoscopic frog was employed, as in 

 Sect. II., after the first effect of the nerve current 

 was over, there was no further contraction, however 

 long the nerve was stimulated; there was no effect 

 corresponding to the tetanized muscle; it was im- 

 possible to produce a tetanic condition of the nerve, 

 so that it should affect the nerve of a galvanoscopic 

 frog''. 



^ What the condition of the nerve may be along which the 

 inverse current has passed for some time, so as to produce 



