LIVING TORPEDOS IN BERLIN. 505 



observable by the means employed, when the current strength 

 exceeds a certain limit, and secondly, that the irreciprocity increases 

 with the current strength. By performing the experiment on 

 preparations of different transverse section, one is convinced, thirdly, 

 that the question here concerns not current strength, but, as was to 

 be expected, current density. Fourthly, it follows from the above 

 numbers, that within its sphere, irreciprocity increases more slowly 

 than current density. If we take (see below, 13) the difference 

 between the homodromous and heterodromous current strength 

 with the same transverse section, divided by the homodromous 

 current strength, as a measure of the irreciprocity (a method 

 of proceeding which will be justified later), then we find the 

 irreciprocity 



i*3 3 



at 10 cm. CD = 2iL 0-0481, 

 37-66 



at o cm. CD = ?-l = 0-5549, 



477-0 



instead of = 0-8393, as & would be if the irreciprocity were pro- 

 portional to the current density. There can hardly be a doubt 

 that the irreciprocity, referred to the current density, would approach 

 asymptotically to a fixed limit. 



8. The apparent irreciprocity of conduction in the elec- 

 trical organ has its seat in every transverse lamella of the 

 preparation, and increases with the length of the columnar 

 tract which is traversed by the current. 



I next convinced myself, that the difference in the strength of 

 the currents becomes perceptible, not merely when they are led 

 from the one polar surface of the preparation covered with skin to 

 the other, but also between any points whatever of the lateral 

 surfaces of the preparation, and the difference is the greater the 

 further the points are separated from each other. 



I again led the opening shocks of the inductorium, by opening 

 the mercury key, through the preparation and galvanometer, but 

 this time in accordance with the aim of the experiment, the 

 preparation was not traversed by currents from skin surface to skin 

 surface, but the clay points of the non-polarisable tubes, which 

 took the place of the conducting vessels in the circuit containing 

 the galvanometer and the secondary coil of the inductorium, were 

 brought into contact with the lateral surface. The secondary coil 



