LIVING TORPEDOS IN BERLIN. 463 



electromotive observation had been made with respect to electrical 

 nerves ; and unfortunately Sachs let the opportunity pass by of 

 filling up the gap by his observations on Gymnotus 1 . 



Even the Italian electrophysiologists did not make use of the 

 advantages offered them by Nature, and so it was, strange to say, 

 reserved for me more than forty years after the discovery of the 

 nerve-current, in the Physiological Institute of this northern 

 metropolis, to bring Torpedo nerve for the first time into the 

 galvanometer circuit. This occurred on the first occasion that I 

 had the opportunity of killing a Torpedo, viz. on the I3th of June 

 of last year. As it was uncertain how long the nerves would 

 remain alive in summer temperature, I begged Prof. Christiani to 

 undertake this investigation while I occupied myself with experiments 

 on polarisation in the organ. Professor Fritsch was so kind as to 

 prepare for experiment the nerves with which he was so familiar. 



The eight electrical nerves of a large torpedo, four on each side, 

 form, as I had anticipated, an excellent object of investigation 2 . 

 They are easily prepared without branches, as long as from three to 

 4 cm., and at an average thickness of 2-5 mm. Even if they do 

 not as electrical nerves differ from other nerves, they will afford 

 the means of obtaining solutions hitherto unattainable of problems 

 in the general physics of nerves. 



i. Current of rest of the Electrical Nerves of the Torpedo. 



Shortly before undertaking the measurement of electromotive 

 force in the electrical nerves 5 a similar measurement with the same 

 apparatus was made of the N. ischiadicus of the frog, and yielded 

 the ordinary values of 0-014 ^ 0-022 Rauolt. The portions of 

 electrical nerves were of the same length as those of the ischiadicus, 

 viz. 12 to 15 mm. From the greater thickness of the former it 

 might be expected that with an equal specific electromotive force 

 there would be a greater galvanometric effect. This was not the 

 case. Christiani obtained the following numbers from the electri- 

 cal nerves : 



I. II. III. lib. 



0-0054 0-0086 0-0054 0-0089 



The number under lib relates to another animal used on the 27th 

 of June. The greatest force obtained by Prof. Christiani is more 

 than twice as small as that of the nerves of the frog, more than 



1 Untersuchungen, p. 171. 2 Wiener Sitzungsberichte, 1883, i. p. 387. 



