LIVING TORPEDOS IN BERLIN. 537 



relatively positive polarisation, different from the shock and due 

 to the homodromous current. A completely reliable proof of the 

 correctness of the one or the other conception is wanting, such 

 as would be afforded by a more frequent recurrence of the 

 behaviour exhibited in the second series, as a set-off for the failure 

 in obtaining- the result sought after in 6. 



16. On conduction in both directions in the electrical 

 nerves of the Torpedo. 



In the experiments of the first communication, one question 

 among others remained unanswered, which has indeed been decided 

 long ago, but can never be too frequently made the object of 

 renewed examination, viz. the question as to conduction in both 

 directions (doppelsinnige Leitung) in the electrical nerves, the purely 

 centrifugal character of which gives them inestimable value for 

 this purpose. The first experiment which I made on the first fish 

 (the one in a condition of opisthotonus) last summer, was aimed at 

 this question. 



With 1 0,000. turns at zero, the feeble current of the electrical 

 nerves could be observed very well : the stronger negativity of the 

 peripheral transverse section, upon which stress was laid in the 

 first communication, could always be clearly made out. Thus I 

 obtained for the nerves of the first Torpedo, which was unhealthy, 

 the following values in Raoults : 



I (left). II. I (right). 



With peripheral. .. ) Transverse ( + 0-00718 + 0-00822 + 0-00568 

 With central \ section... ( 0-00508 0-00568 0-00409 



Difference + 0-00209 + 0-00254 + 0-00159 



These numbers are in complete conformity with those in the 

 first communication. On a later occasion, I tried to prove also that 

 the electromotive force of the current ascending between two 

 transverse sections of the electrical nerves it may be called the 

 axial current increases in proportion to the length of the por- 

 tion of nerve, but I did not succeed in this with the uniformity 

 I could have wished. In observing the axial current between 

 points in the longitudinal section of the uninjured nerve, which 

 I also attempted (comp. p. 465), I met with the difficulty, that 

 since the electrical lobes had been punched out, the negativity of 

 the upper transverse section chiefly asserted itself. It will be 



