338 INHIBITION BY EXCITATION AND 



This fact may however be established with greater certainty and 

 in a more complete manner with the aid of the simple artifice 



Fig. 8. 



Fig. 8 represents the effect of exciting the M. sartorius of Rana temporaries 

 after previously poisoning it with veratrine. A single Daniell was always used as 

 the source of the current ; a rheochord was not inserted in the circuit. The muscle 

 was stretched in Hering's double myograph, and it was fixed at the middle. The 

 tracing A is that of the anodic, and K that of the kathodic half of the muscle. Before 

 the special excitation (at C), a tonic contraction of the muscle, lasting a long time, 

 was produced by closing a battery current as short a time as possible, or by a single 

 induction shock. The moments of closing and opening the exciting current are marked 

 by the letters C and O. Its direction was | . In order to economise space, the 

 tracings are shortened in such a manner, that the descending part corresponding to 

 the renewed lengthening of the muscle is only reproduced in part. The phenomenon 

 that the kathodic half of the muscle, on opening the current, is suddenly more 

 relaxed, whilst the anodic half is either shortened or shows no alteration in length, 

 is especially clear here. Both halves of the curve show at C and exactly 

 opposite changes of form. The divisions on the Time Line indicate seconds. 



of fixing- the muscle in the middle in such a way, that while the 

 propagation of the excitation is unhindered, the variations in form 

 of the one half are prevented from affecting the other. In doing 

 this, I employed the same method which has already been dis- 

 cussed in detail in an earlier communication 1 and I need not 

 therefore give a minute description of it here. 



1 Hering, 'Uber die Methoden zur Untersuchung der polaren Wirkungen des 

 elektrischen Stromes,' &c. Sitzungsber. vol. Ixxix. 



