PRESENT STATE OF ORGANIC ELECTRICITY. 339 



energy, into a plus and minus state, like that of a charged 

 phial ; and that the current results from a conducting medium 

 between their opposite surfaces being supplied naturally or 

 artificially. Galvani originally, Becquerel subsequently, and 

 latterly Matteucci, conceived the batteries to be charged by 

 electricity developed in the brain, or central organ of the ap- 

 paratus. Eudolphi considered the perpendicular prisms in 

 Torpedo as galvanic piles, the horizontal series in Gymnotus 

 as trough arrangements ; but without entering into the details 

 of the comparison. This view of their action does not explain 

 the intermittent and voluntary character of the electric dis- 

 charges. For, as Valentin has stated, the organs in the fish 

 cannot be complete galvanic batteries, or they would be 

 continually charged, and a current would follow every suit- 

 able closure of the circuit. Valentin proposes the follow- 

 ing theory of the apparatus. He assumes the structure of the 

 battery to be a series of closed spaces ; the series enveloped in 

 thicker, the spaces separated by thinner aponeurotic laminae ; 

 each space being lined by a vascular epithelium, under 

 which the nervous plexuses lie, and filled with fluid. He 

 supposes that there results from the organic or nutritive 

 reactions of the circulating blood, the epithelium, and the 

 contained fluid of each space, a certain amount of electric 

 force,, not, however, sufficient to overcome the insulating ob- 

 stacle opposed to it in the aponeurotic walls ; all the spaces in 

 the battery are, therefore, so far only insulated electrical 

 spaces. As soon, however, as the will of the animal deter- 

 mines a flow of nervous force into the spaces, the organic re- 

 actions become so much exalted that the resolved electric 

 force overcomes the insulating power of the laminae, and a 

 current is produced ; the current being confined to the series 

 by their thicker aponeurotic walls.* This theory, although it 

 may account for a sudden increase of electricity in the organ, 



* " Electricitat der Thiere " in Wagner's Handworterbuck. ., 



