ON LIVING MALAPTERURUS. 393 



circuit remained unexcited. If their nerve was in the circuit, 

 twitches presented themselves, as also when the nerve of a nerve- 

 muscle preparation was placed on a gastrocnemius included in the 

 circuit, though the muscle did not itself twitch. But the latter 

 twitches were of unipolar origin, as it was easy to prove 1 . On 

 frequent repetition of the experiment, and especially if the shocks 

 were somewhat strengthened, the slit easily fused together. 



In these experiments, the discrepancy which had always been 

 observed between the strength of the shock in Malapterurus as 

 otherwise tested, and its striking distance, manifests itself afresh, 

 and if I mistake not, more clearly than hitherto. It was ever a 

 matter of surprise that such a powerful shock as that of Gymiiotus 

 should show itself so sensitive to hindrances in its path, that it will 

 not pass through flame 2 , nor even through loosely hanging chains 

 of one of the baser metals, and that it is scarcely perceived with dry 

 copper handles 3 . On account of this behaviour, the identity of the 

 force emanating from electrical fishes with ordinary electricity, was 

 doubted for a long time, and Cavendish sought in vain to remove 

 this diffculty in those theoretical investigations which were far in 

 advance of his time, in which he compared the shock of the 

 electrical fish to that of a battery of great capacity but small 

 tension, which also does not pass readily through a chain 4 . 



I now give the direct proof of the imcomparable superiority, as 

 regards striking distance, of the shocks produced by our apparatus 

 to those of the electrical fish. I am also in a position to give the 

 solution of this enigma, which has escaped all earlier investigators 

 of such fish. 



Let two equal currents I a = T b flow into two conductors A and B 

 of the resistance A. Let the ends of the conductor be connected 

 by a side conductor of the resistance A 15 whilst the conductor A 

 forms a part of an unbranched circuit. If the resistance A. of the 

 two conductors is increased by the same magnitude 6, it can be 

 shown that I b loses thereby more than I a in strength. Let E be 

 the electromotive force in the unbranched circuit, of which A forms 

 a part, let n be a constant > I, and w the actual resistance in both 

 circuits, then we have 



1 Untersuchungen, etc., vol. i. p. 4233". 



2 Humboldt in Observations de Zoologie et d'Anatomie comparee, etc. Paris, 

 1811,4. p. 84. 



3 Faraday, loc. cit. p. 5, 1760. 



4 Loc. cit. pp. 217-222, 224, 225. Comp. Untersuchungen, etc., vol. i. p. 563. 



