But the great majority of cases require--not a generalized, but a strictly localized application, and for the fundamental principles of all methods of localized electrization we are indebted to the late Dr. Duchenne (the “father of electro-therapeutics”), for before him no one had attempted any local application of electricity that could properly be so called. Indeed, to Duchenne may be fairly ascribed the very birth of medical electricity as a branch of therapeutics, and in the true and kindly words of the _Lancet_, when announcing his death:--“No field of work was ever seized upon with more eagerness; ever cultivated with more earnestness; or perhaps ever made to yield a better harvest than that which the discovery of induced electricity placed at the disposal of the man whose genius was the first to recognize, and his talents to secure, the opportunity it afforded. Taking his work at its lowest estimate, he was a man to whom medical science owes a large debt of gratitude, and whose memory deserves a warm tribute of regard.” Duchenne’s two test experiments, demonstrating the fundamental principles of his method, I will now repeat upon the posterior surface of my left forearm. I propose to arrest Faradism in the skin, without allowing it to stimulate the subjacent muscles. To do this it is necessary for the skin to be quite dry--moisture, as you know, being a conductor of electricity--and to make sure of sufficient dryness, I sprinkle the skin with a little starch powder. I now apply to the dry skin the dry metallic conductors of an induction instrument in action. I am afraid you cannot see, Gentlemen, the small sparks produced as the two electricities combine upon the cutaneous surface, or hear the slight crackling sound produced, but you observe no muscular contraction, and what I feel is a superficial and evidently cutaneous sensation. I now replace the dry conductors by well-moistened sponges. You observe that I have not altered the power of the current, but that there is energetic contraction of the extensor muscles. This is quite involuntary, and is due to the electric irritation of the branches of the motor nerves.