Electro-physiology and electro-therapeutics : showing the best methods for the medical uses of electricity / By Alfred C. Garratt.

we may conclude, he says, that the nervo-electric polarity of the motor nerves is more easily disturbed, at least by the electric current, than the molecular equilibrium of the fibres of the muscles. But my own opinion is, that electro-muscular contrac- tions are most readily obtained; i. e., with the least pain, and by means of a less current, and that more uniformly, if we place one electrode over the nerve trunk, while the other elec- trode is made to glide along nicely and obliquely over the farther side of the muscle — a manoeuvre which is readily learned, but not so easily described. Electro-Physiological Researches and Creeds. We said in the chapter of history that Volta objected to the theory of Galvani; but, at the same time, we find he took up these nervo-electric phenomena, first discovered by Galvani, as a nucleus of vast significance; and he, therefore, made them the subject of his most rigid investigations up to 1800. First, we see, it was reserved for him to show that the metal arc em- ployed by Galvani to produce the muscle contractions was not a simple conductor, but as being in and of itself a source of electricity, because it consisted of two dissimilar metals. From this stepping stone, placed for him by Galvani at first, Volta becomes the discoverer of the electric pile, which bears his name, and also the author of the contact theory. After this, the great object of his life seems to have been to show the cor- respondence in every particular between the contact current, as he then termed it, and the electric current, obtained by the fric- tion machine, then already so well known. There were, how- ever, those who doubted. In this connection, we may see motives which lead Volta to seek to prove, by every possible means, " the identity of the electric and galvanic fluid." Volta also endeavored to remove all those theoretical difficul- ties which were presented, arising from the steadiness of the work- ing of the closed pile, as it was then understood. Although uninterrupted chemical workings, as the decomposition of water, for instance, was very probably known to him, yet when, refer- 15*