314 riiysioLotiY or MTSCLES AND NKKYJ .-. 



branch-Currents of tin- electric current used for irritation, 

 which miijit e.-isily 1 -ml to errors, are pre ent ill the mul- 



tiplier. 



13. ELE:TUOTONUS. SECONDARY PULSATION EFFECTED BY 

 NERVES. PARADOXICAL PULSATION (p. 221). 



The reason why it is impo-sible to examine the electro- 

 tunus of the intrapolar portions is purely physical. It' the 

 constant current is trausmitt d through the portion a k 

 (fig. GO, p. 220), and two points of this portion are o>n- 

 neeted with the multiplier, then a part of this current p. 

 through the multiplier itself, so that the portion of the 

 in rve which is situated between these points is travei>ei| 

 I >y a weaker current than are the adjacent portions. The 

 condition- ore thus rendered so complex that it becomes 

 very hard t;> explain the phenomena. Other attempts to 

 study the character of the intrapolar regum have as yet 

 aUbrde-d no clear results. 



If a nerve a is laid on a nerve //. in the way sh<,\\n in 

 liir. ".">, A,B, 6', so that the nerve // forms a diverting arch for 

 a portion of the nerve a, and if electrotonus is generated in 

 the lutt.T liy a coiistant current, 1 lien the electrotonic cnr- 

 r.-nt passes through tlie nerve J, and can at its commence- 

 ment and cessation (closing and opening) excite the in rjc !>, 

 :ind cause pulsation in the muscle of the nei ve. Tliis is 

 spoki-n of as .s- condary pulsation from tin nerv . l'-\ rapidly 

 re|iOateil closings and openings of the circuit, tetanus may lie 

 elicited. I'.ut this secondary ]iulsation is caused only by 

 eVetrotoniis and not. by ne-.iii\e variation, so that it can 

 !. more easily brought almiit by constant currents than by 

 inductive current^. h i ihus distin^ni>lied from the xx-mi- 

 fm-i/ inilantiiin ,j/', </:/ I,,/ /////.s-.-/ , -which was di'sciibed on 

 p. _"!. The negative variation of the nerve eiirivnt i 

 \\<:.k to Cause any not ic 'able etl'i cl in a second nerve. 



