378 Dr. C. B. RadclifiVs Researches in Animal Electricity. [Apr. 8, 



solution by having one of their ends dipping into it — electrodes which, 

 to say the least, are not easily put in order or kept in order. 



II. On the Electrical Phenomena which belong to Living Nerve and 

 Muscle during the state of rest. 



Living nerve and muscle supply currents to the galvanometer (the 

 nerve-current, and the muscular current, so called) which are not supplied 

 by dead nerve and muscle. These currents, when the tissues supplying 

 them are fresh and at rest, show that the surface composed of the sides of 

 the fibres, and the surface composed of the ends of the fibres, are in op- 

 posite electrical conditions, the former surface being positive, the latter 

 negative. These currents, when the tissues supplying them are about to 

 die, and, in some cases, when they are put in action, are wholly or par- 

 tially reversed — are so changed in direction, that is to say, as to show that 

 there is at this time a total or partial reversal in the electrical relations 

 of the ends and sides of the fibres. The fact of a partial reversal, in 

 which the fibres may be positive in some part of their sides and negative 

 in others, or positive at one of their ends and negative at the other, is now 

 pointed out for the first time. 



Nerve and muscle, and the animal tissues generally, oppose a very high 

 resistance to the passage of a common voltaic current — so high, indeed, as 

 to justify the inference that muscles and nerves may be looked upon as 

 non-conductors rather than as conductors. The resistance in an inch of 

 the sciatic nerve of a frog, for example, is about 40,000 B.A. units, or 

 nearly seven times that of the whole Atlantic Cable. 



The mean tension of the nerve-current and the muscular current proves 

 to be about half that of a Daniell's cell. Moreover, negative and positive 

 electricity, in equal amounts, are both found to be present. The case is 

 not one in which only one kind of electricity is present, — in which what 

 appears to be negative is only a lower degree of positive, or vice versa ; it 

 is one in which two electricities are present, one above the zero of the 

 earth, the other below it — one as much above the zero of the earth as the 

 other is below it. These facts are made out by means of the potentiometer. 



Looking at these facts, and especially at the comparative non-conducti- 

 bility of nerve and muscle, wholly or in part, and at the presence in these 

 tissues of positive and negative electricity in equal quantities, it is thought 

 probable — 



That the comparative non-conductibility of nerve and muscle may allow 

 certain parts of these tissues to act as dielectrics rather than as conductors, 

 and that these parts may be the sheaths of the fibres. 



That the development of one kind of electricity (by oxygenation, or in 

 some other way) on the exterior of the sheaths of the nerve and muscular 

 fibres may lead, by induction, to the development of the other kind of 

 electricity on the interior of these sheaths. 



