NATURAL PHILOSOPHY. 115 



tity of electricity through the liquid, and connecting the ring of mer- 

 cury with the negative platinum wire. The ring of mercury imme- 

 diately became covered with crispations or elevated sharp ridges, 

 about one-sixteenth of an inch asunder, all radiating towards the 

 centre of the vessel, and a definite or musical sound was produced, 

 capable of being heard, on some occasions, at a distance of about 

 forty or fifty feet. The vibrations and sounds ceased after a short 

 time, but were always reproduced by reversing the direction of the 

 electric current for a short time, and then restoring it to its original 

 direction. The loudness of the sound depends greatly upon the power 

 of the battery ; if the battery was too strong the sounds did not 

 occur. The inference drawn by Mr. Gore from these experiments is, 

 that voltaic electricity, like heat and light, may be viewed as consist- 

 ing of vibrations, which are ordinarily inappreciable, but which, un- 

 der certain conditions, such as these described, may be gradually in- 

 creased so as to become visible. These results are evidently worthy 

 of the most attentive examination ; their value as tending to eluci- 

 date the nature of voltaic electricity can hardly be overrated, al- 

 though it is evident that a sufficient number of facts are not yet accu- 

 mulated to prove the inference that has been deduced. 



THE ELECTRIC ORGAN IN FISHES. 



The hypothesis propounded by Sir John Herschel, and eagerly 

 adopted by many physiologists, that the brain is a voltaic battery of 

 which the nerves are the conductors, was retained as a convenient 

 simile, after the identity of nerve force and electricity had been gen- 

 erally discredited ; and the nerves were then spoken of as conductors 

 of the force generated in the nerve-centres. Even as a simile, how- 

 ever, this became inadmissible when it was proved that the nerves 

 were in no sense conductors, but possessed their own special force, 

 neurility, which could operate in complete independence of any 

 centre, and which was to the nerves what contractility was to the 

 muscles, and sensibility to nerve-centres. The hypothesis of the bat- 

 tery, and the hypothesis of nerve-force being electricity, seemed con- 

 firmed by the electrical phenomena exhibited in certain fishes, which 

 have justly excited considerable attention from men of science. The 

 fact that the electric organ is connected with the brain by an enor- 

 mous mass of nerves, and the fact that the discharge is under the 

 control of the animal's will, together with the fact that destruction 

 of the brain on one side destroyed the electrical power on that side, 

 an effect also produced by merely dividing the nerves, so as to cut 

 off the communication with the brain, seemed to establish the 

 hypothesis of the brain's being the central battery. 



This has now been thoroughly disproved. M. Charles Robin long 

 ago suggested that the electric organ, and not the brain, was the 

 source of the electricity discharged. He declared that the tissue of 

 this organ has the special property of producing electricity, just as 

 the muscular tissue has the special property of contractility ; and the 

 influence of the nerve force is similar in both cases, exciting the 

 activity of the electric tissue as it excites the activity of the muscular 

 tissue. Against this it was maintained that the brain generated the 



