526 LIVING TORPEDOS IN BERLIN. 



tunately postponed the repetition of the experiments with feeble 

 opening shocks with a galvanometer of greater sensitiveness, and 

 it is possible that a difference, too small to be detected by the 

 galvanometer of the sensitiveness employed above (p. 517), might 

 thus be proved to exist. However that may be, it may be assumed 

 for the present, that to the right of and above the line A g (the 

 threshold line) with the ineans of observation actually used, the 

 tops of the ordinates, representing the heterodromous resistances, 

 seem to lie in the plane ?i , 5 , 4 parallel to the 2-A-plane. But 

 to the left of this line, the heterodromous resistance becomes so 

 much the greater, as the density is greater and the time of closing 

 is less. Thus with increasing density and decreasing closing 

 time, the tops of the ordinates r rise above the plane w , 2 , 3 , 4 , 

 so that they lie in the surface of complex curvature r lt 2 , 3 , 4 . It is 

 to be assumed that the heterodromous resistance, with increasing 

 current density, approaches a limit (see above, p. 505) ; this is 

 expressed by the course of the curve of heterodromous resistance 

 for minimal duration of closure, which as it nears r 2 becomes 

 concave towards the axis. With increasing duration of closing, it 

 approaches an inferior limit, as is expressed by the curve r 2 , 3 , 

 which unites itself asymptotically with w 2 , 3 ; that is with a line 

 parallel to the time axis ; there will however be somewhat to 

 remark upon this later on. 



This gives upon the whole the main features of the law of the 

 phenomenon. The mode of formulating irreciprocity (pp. 504, 505) 

 seems now to be sufficiently justified. It is at present impossible 

 to form a satisfactory conception as to the cause of the phenomenon. 

 At first the idea may occur, that it is somewhat similar to the 

 internal secondary resistance, which I have described in the case of 

 a porous moist conductor, in which the internal resistance increases 

 with the current density 1 . The analogy between the two phe- 

 nomena is however scarcely a true one. The internal secondary 

 resistance has this indeed in common with heterodromous re- 

 sistance, that boiling temperature destroys it. But disregarding 

 the fact that hitherto it has been observed in living tissue of 

 plants only, it is independent of the direction of the current, it 

 demands longer time of closing for its development, and, when once 

 developed, longer time for its disappearance, whilst, on the contrary, 

 heterodromous resistance is present to its greatest extent at the 



1 Gesammelte Abhandlungen, vol. i. pp. 90 f., u6f. 



