492 



STUDIES IN GENERAL PHYSIOLOGY 



somewhat closely, we find that in this experiment the nerve 

 accidentally lay parallel to the metal plates and somewhat 

 outside the area inclosed by the metal plates. This is no 

 other experiment than that which I have described under 6), 

 and which is shown in Fig. 140. In order to convince 



oneself of this fact one 

 needs only to turn the 

 nerve through an angle 

 of 90, as I have done, 

 and lay it parallel to 



<d = \/ the line connecting the 



~~ ~i~ electrodes (Fig. 145); 



FIG. 145 ,, i , . 



one then obtains maxi- 

 mal effects when the nerve lies symmetrically with refer- 

 ence to the metal plates. We do not deal, therefore, with 

 interference in Danilewsky's experiment, but (as I had 

 already shown in my first publication) with the well-known 

 fact that the nerve is insensitive, or only slightly sensitive, 

 to a current which passes through it transversely. I con- 

 vinced myself of the correctness of this interpretation in yet 

 another way. One can also obtain minimal effects when the 

 nerves lie at right angles to the electrodes and in a dissym- 

 metrical position, if the 

 nerves are brought 

 entirely within the area 

 between the two metal 

 plates as shown in Fig. 

 146. In this way cur- 

 rents are obtained which 

 pass transversely through the nerves. 



The "interference experiments" of Danilewsky are not 

 only misinterpreted as far as the purely physiological facts 

 are concerned, but their physical analysis leads also to im- 

 possibilities. In Danilewsky's experiment a spark does not 



A 



V 



FIG. 146 



