OF THE GALVANIC CURRENT ON THE MOTOR NERVES OF MAN. 
991 
Tracing 34. To show kathodic after-effect. Distance of secondary from primary coil 
9*5 centims. No additional resistance in circuit. The first group to the 
right of the tracing is of induction kathodic contractions before polarisation; 
the second group is of contractions by the same induction current during the 
8th minute of kathodic polarisation by 20 cells (12 m.w.). The following 
series shows the absence and subsequent rise of contractions after polarisa¬ 
tion. The small groups to the left of tracing, marked 1, 2, 3, 4, 5, 6, 7, are 
of contractions taken at the end of 1, 2, 3, 4, 5, 6, 7 intervals of 15 minutes 
each, and shows the gradual decline of excitability, the strength of the 
induction current remaining the same (9‘5 centims.) throughout the experi¬ 
ment. 
Tracing 35. Series of kathodic closure contractions alternately without and with an 
uninterrupted galvanic current in the same circuit, 1000 ohms in circuit. 
Each series last about 1 minute, the duration of current made is about 
1 second, that of the interval is about 2 seconds. The strength of current 
giving the K.C. contractions is the same throughout, viz. : by 10 cells 
(6 milliwebers). In the three successive series taken during the passage 
of the uninterrupted current, the strength of the latter is increased, being 
by 2, 4, and 6 cells in each successive series. The figure shows that the 
augmentation of K.C.C. is greater with greater strength of the polarising 
current. 
Tracing 36. Series of anodic closure and opening contractions by 30 cells (23 milli¬ 
webers) taken on the same plan as the preceding series, with and without an 
uninterrupted galvanic current in the same direction. It shows augmenta¬ 
tion of A.C.C. and diminution of A.O.C. increasing with increasing strength 
of the polarising current. On comparison with the preceding series it may 
be recognised that the augmentation of A.C.C. during polarisation is less 
marked than that of K.C.C. 
6 L 
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