494 STUDIES IN GENERAL PHYSIOLOGY 



We are dealing simply and solely with the lesser irritability 

 of nerves to transverse currents. 



The second experiment of Danilewsky is intended to show 

 that we are not dealing with electrostatic effects. He 

 obtained electrical effects when the secondary coil of the 

 Ruhmkorff coil was closed by means of the secondary coil of 

 another induction apparatus. I have repeated this experi- 

 ment, and have found that it is in reality nothing else than 

 the experiment discussed before, and that we can therefore 

 speak as little of the effects of an oscillatory discharge, or of 

 electric waves, in this case as in the previous experiment. 

 To convince oneself of this fact one needs only to close the 

 circuit of the secondary coil of the Ruhmkorff through a 

 rheostat instead of with the spiral of an induction apparatus. 

 If a great resistance is introduced into the rheostat, about 

 20,000 ohms, all the experiments which I have described 

 under a) and 6) can be repeated between the terminals of 

 the Ruhmkorff coil. When a resistance of only one ohm is 

 introduced, no effects are obtained ! In this case, therefore, 

 we also deal with the production of a high potential at each 

 side of the resistance through the introduction of a high 

 resistance. These charges bring about an electrostatic 

 separation of both kinds of electricities in the muscle prepa- 

 rations. As soon as the discharge takes place, a current 

 passes through the nerve which brings about maximal effects 

 when it passes longitudinally through the nerve; minimal 

 effects when it passes in a transverse direction. The experi- 

 ments succeed most beautifully when the secondary spiral of 

 the Ruhmkorff is closed through a glass tube filled with 

 distilled water into each end of which dips a copper wire. 

 In this case the glass tube behaves physiologically exactly 

 as the path of the spark in my first-described experiments, 

 and one can here repeat all the experiments which I have 

 discussed in my first publication. But this is possible only 



