344 INHIBITION BY EXCITATION AND 



dilute solution of acetate of veratrine, and by this method I have 

 attained quite unequivocal results. 



Before I proceed to state these results, I will briefly mention the 

 experimental means which were available for my experiments. 

 I had at my disposal a new large reflecting galvanometer with bell 

 magnets by Edelmann of Munich ; this presents a very substantial 

 advantage for the intended experiments, inasmuch as its extremely 

 strong damping renders nearly perfect aperiodicity possible without 

 the use of Hauy's bar magnet. The magnet comes to rest in 

 little more than a second. 



The bobbins of the Edelmann instrument have however, on 

 account of their large dimensions and the great number of turns, 

 a resistance much too considerable for the present experiments, and 

 I therefore used in their stead two bobbins with a less number of 

 turns, made after Professor Bering's design. Each of these consists 

 essentially of a copper hemispherical cup with thin walls, and when 

 the bobbins are as close as possible to each other, the cavities of 

 the cups almost enclose the spherical damper ; the wires are wound 

 directly over these copper capsules, and thus the greatest part of 

 the space which would be injurious, and which is left empty even 

 when the Edelmann bobbins are in actual contact, is made of use ; and 

 at the same time the coils lie much closer to the magnet here than 

 there, so that notwithstanding their smaller number, the sensitive- 

 ness of the instrument is considerably increased. 



When I led off from the artificial transverse section of a sartorius 

 and from a corresponding point at about the middle of the muscle, 

 with the brash electrodes already mentioned, I observed on an 

 average a deflection of 40-50 scale divisions when the scale was 

 at a distance of about 2-5 metres. The sciatic nerve of a larger 

 frog gave deflections of 5-8 scale divisions, when led off from 

 a tract about I centim. long under similar circumstances. 



This amount of sensitiveness proved to be quite sufficient to 

 demonstrate with all the certainty desirable, electromotive effects 

 even much more insignificant than those concerned in the ex- 

 periments which are about to be described. At the same time, 

 the instrument offers the advantage which ought not to be under- 

 estimated, that the rapidity with which the magnet obeys the 

 directing forces, makes it possible to recognise differences of -tension 

 which change their signs very quickly. 



. I may refer to previous communications for all the rest of the 

 arrangements for the experiments, because they agree precisely 



