282 



ELECTRO-PHYSIOLOGY 



CHAP. 



traversed muscle, and contributes nothing in regard to the 

 excitability of the intrapolar region. Besides this principal 

 fallacy, his experiments are also hampered by the use of metal 

 electrodes, which complicate the results by polarisation. 



In order to determine the polar excitability of a curarised 

 muscle with parallel fibres, traversed by a constant current, from 

 the above method with as few fallacies as possible, and during the 

 passage of the current the uninjured sartorius, with its stumps of 

 bone at either end, must be attached to the double myograph 

 with unpolarisable electrodes, one of which is permanently fixed, 

 while the other is movable, and connected with a writing lever. 

 The arrangement is such that the polarising constant current and 

 make induction current traverse the muscle in the same ascending 

 or descending direction. 



In order to obtain a general notion, and also for better 

 comparison with the results of v. Bezold, we subjoin two out of 

 many tables of results in which the same method is followed on 

 the whole as in the analogous experiments of v. Bezold : 



1. 



2. 

 3. 



4. 

 5. 

 6. 



7. 

 8. 



9. 

 10. 

 11. 



Twitch. Muscle unpolarised 



Immediately after closure of very weak de- 

 scending 1 current (2 Dan. rheochord res. = 1) 



Immediately after breaking this current 



Muscle unpolarised 



Immediately after closure of strong descending 

 current (res. = 4) . 



On breaking this current 



Polarising current strengthened (res. = 8) 

 immediately after closure 



3 sees, later .... 



Immediately after opening the current 



1 minute later 



Height of 

 Twitch. 



4 mm. 



4 



29 

 4 

 4 



32 

 3 



26 



,, 

 

 trace 



II. 



1. Twitch. Muscle polarised . . .6 mm. 



2 fi 



}> " u 



3. ,, Immediately after closure of weak descending 



current (2 Dan. res. = 1) . . 29 



1 Descending and ascending currents vary in effect because of the asymmetrical 

 form of the sartorius. 



