1870.] Dr. C. B. Radcliffe on Animal Electricity. 



23 



death. This electricity is made known by the electrometer, as* well as by 

 the galvanometer. Living nerve and muscle supply to the galvanometer 

 currents, called respectively the nerve-current and the muscle- cur rent, 

 when the sides of the fibres are connected, through the coil, with either 

 one of the two ends, or when certain points upon the sides or upon the 

 ends are brought together in the same manner, the direction of these cur- 

 rents showing that the sides of the fibres are positive in relation to either 

 of the two ends, or else the reverse (the instances of reversal being the 

 exception and not the rule), and that the positive surface becomes more 

 positive, and the negative surface more negative, as the distance from the 

 line of junction between these surfaces increases. Living nerve and muscle 

 are also (as is now for the first time distinctly proved by means of Thom- 

 son's New Quadrant Electrometer) capable of acting upon the electro- 

 meter, the action showing that the electrical differences upon which the 

 nerve-current and muscle-current depend are not the same in all parts of 

 the fibres, the differences between the sides and the ends being differences 

 in kind, like those which belong to the two surfaces of a charged Leyden 

 jar, the differences upon the sides singly, and upon the ends singly, being 

 only those which indicate different degrees of tension in one kind of elec- 

 tricity. In accounting for these phenomena, the very imperfect conducti- 

 bility of nerve and muscle, and of animal tissue generally, is taken as a 

 starting-point. It is assumed (and in support of this assumption some 

 new measurements of the resistance of nerve and muscle to electrical con- 

 duction are given) that in nerve and muscle the sheaths of the fibres may 

 conduct electricity so imperfectly as to be capable of acting as dielectrics y — 

 that a charge of one kind of electricity, developed on their outsides (by 

 oxygenation'or in some other way), may induce an opposite charge on their 

 insides, — and that the electrical condition of the two ends of the fibres may 

 be opposed to that of the sides, because the charge induced within the 

 sheath is conducted to the ends by the contents of the sheath, It is sup- 

 posed, in short, that the fibres of living nerve and muscle during rest are 

 so many charged Leyden jars, their electrical condition at this time being 

 statical, not current, and that the nerve-current and muscle-current are no 

 more than accidental phenomena arising from the galvanometer being 

 placed between two points which happen to be electrically dissimilar. And 

 in support of this view it is pointed out that precisely parallel electrical 

 phenomena may be obtained from a piece of wood, shaped like the piece of 

 nerve or muscle, and coated on its sides, but not at its two ends, by a sheath 

 formed of two layers of tinfoil separated by an intermediate layer of thin 

 gutta-percha sheeting, if only the sides be charged as the sides of the piece 

 of nerve or muscle are supposed to be charged, and if the electrodes of 

 the galvanomer or electrometer be applied in the proper manner. 



2. The electrical phenomena which mark the passing of nerve and muscle 

 from the state of rest into that of action. 

 Argument. — The nerve-current and muscle- current disappear almost 



