m- MUSCLES AM> M:K\ : 



", we have really to ilo with a closing imme ti it -ly sttC- 

 c vded liy an opening, for the inductive current ai i~e., mil 

 a,' mi disappear:- as SOOD as it lias r.-aeh-d si c.-rt tin strength. 

 Th> may lie imitat -d with suitable apparatus, l.y closing a 

 cm-taut current for a very l>rkf time. Such a ; cm rent 

 sho,-k ' may exhih'.t exactly the same phenomena as does an 

 inductive current. If its duration remains unaltered, hut 

 the strength of the current is giadually increased, the height 

 i.t' elevation at first increases, remains for a time at a first 

 maximum, after which it again increases and reaches a second 

 maximum. Tho explanation is the same as was given in 

 Note :; I'm- inluctive currents. At first only the beginning 

 of the current (the closing) acts excitingly; but when the 

 current H stronger, the cessation of the current (the o|ienin^ ) 

 c.ni also act in the snne way. and a comliination of the two 

 irritant* cm l,c t'onued. 



If the duration of such a current shock i-> very >hort. I he 

 current mu>t he M rongi-r, if it is to exercise any exciting 

 elVect at all, than would he in n -.sary if the duration were 

 longer. It is evident that a current, if it lasts too short a 

 time, cannot effect a sufficient chang,- in t!ie molecular con- 

 dition of the nerve, and weaker currents require a longer 

 time t:> do this than st rongor. 



From the curves in fig. ~'.'> \\!;ic'i ivpreseiit the duration 

 of inductive Currents, it apjicars that without exception the 

 commencement of the current results more abruptly than its 

 disappearance. The coniinenc'-ment of every inductive cm- 

 rent must th>-re!'ore inure easily excite than dues its end, 

 esp 'cially as this isalwavs the case 'Vcii in the ordii arv 

 closing and opening of e\ ery coiislant cm rent, in which such 

 e.-n-ideralilc diflerenci-s in the duration do not occur. In 

 the case of weak inductive cunents il is always only the 

 uiiimencement which is active, in other words mi 'nuliicttr 

 i-in-i-i ni HI-IK a* :lu s tl/' i-JiiKiinj (if a continuous c///-r< uf. 



Now let US suppose that all inductive current is pas>ed 

 through a nervein an a-c-'iidiug direction. So long :is the 



