244 Electricity and Galvanism. 



revolting a scene that many spectators fainted at the sight. But 

 this experiment on the recently executed murderer, striking as it 

 was, merely afforded an additional proof of the susceptibility of the 

 muscles to the stimulus of the electric current, and, when divested 

 of the dramatic interest investing it, becomes not more remarkable 

 than the first experiment of Galvani on the leg of a frog. 



Secretion and nervous agency have always been the favourite phe- 

 nomena which electricity has been called in to explain, and with some 

 considerable appearance of probability. Dr. Wollaston, 36 years ago, 

 first suggested from the re-solution of salts into their elements under 

 the influence of feeble currents, that secretion depended essentially 

 upon the electric state of the secreting glands ; he thus regarded 

 the kidneys as constituting the positive and the liver the negative 

 electrodes of the electric apparatus of the body. A curious anecdote 

 is related of Napoleon, who is said by Chaptal to have remarked, on 

 seeing the voltaic battery of the French Academy in action, " Voila 3 

 docteur, V image de la vie ; la colonne vertebral est le pole, la vessie 

 le pole positif, et le foie le pole negatif." We must admit that a 

 great hiatus exists in every argument which assumes that nervous 

 force and electricity are identical, from the fact that delicate as are 

 our tests for this agent, it has never been actually detected traversing 

 the nerves. It has indeed been stated that on connecting needles 

 plunged in the nerve of a rabbit with the galvanometer, and exciting 

 the muscles of the limb to contract, currents have been detected. 

 Other observers of high repute have stated that a steel needle plun- 

 ged in a nerve becomes magnetic during the contraction of the 

 muscle it supplies. Both these statements have been rigidly tested, 

 and have been found utterly unsupported by the results of careful 

 experiment. These failures must not, however, be admitted as quite 

 conclusive against the existence of electricity in the nerves, although 

 their structures are by no means such good conductors as some 

 other of the animal tissues, for it has been well remarked by Dr. 

 Todd and Mr. Bowman, in their elegant and elaborate work on 

 physiological anatomy, that the insertion of needles into the nerves 

 is not a sufficiently delicate means for collecting electricity, if such 

 exists, for they can scarcely be expected to pierce the nerve-tubes, 

 but would sink in between them and the central axis, from which 



