iv ELECTROMOTIVE ACTION IN MUSCLE 453 



other from the behaviour of secondary electromotive phenomena 

 before and after local treatment with water. The mechanical, 

 like the galvanic, effects of excitation are invariably altered in 

 the same way (provided the point of direct excitation coincides 

 with the injured end of the muscle) by every kind of stimulus, 

 localised application included, which produces radical injury of 

 the chemical properties of the muscle-substance : we are there- 

 fore forced into the conclusion that the excitability of the 

 swollen section of the fibre does not at first suffer perceptibly in 

 the case under consideration. On the other hand, there is no 

 doubt that its contractility diminishes considerably in con- 

 sequence of the rigor-like condition of the muscle, even in the 

 earliest stages of the water effect. When, notwithstanding, not 

 merely the continuance of the positive anodic, and negative 

 kathodic after -currents, but also vigorous make and break 

 twitches, are observed on sending current in or out at the end 

 treated with water, we must inevitably conclude that capacity 

 for active change of form at the seat of direct excitation is 

 not essential to excitability in the muscle. It follows that the 

 complete loss of contractility in the etherised muscle can, as 

 little as that of conductivity, be regarded (under similar con- 

 ditions) as a valid objection to the interpretation of polarisation 

 phenomena and of the positive or anodic after-current in 

 particular as the effect of excitation ; the less so since the 

 same facts which tell most decidedly in favour of the view in 

 question can be observed as well on an etherised as on a normal 

 preparation. This applies particularly to the consequences of 

 injuring the ends of the fibres. In every case it may be de- 

 monstrated that the appearance of the positive after-current is 

 rendered impossible when the anodic end of the muscle has been 

 killed by any means whatever. 



The results of this discussion may be summed up in the pro- 

 position that striated muscle under the influence of ether vapour 

 falls into a condition in which the application of an external 

 stimulus produces no directly perceptible changes whether localised at, 

 or distant from, the seat of excitation ; while, on the other hand, 

 galvanometric changes, of equal strength with those produced before 

 narcosis, do appear demonstrdbly at the point of excitation, although 

 in consequence of the abolition of conductivity they are only locally 

 evident. 



