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

cause, is temporarily called forth by the artificial application of the current, at the moment of interruption, or by alternation, or by an increase or decrease in the density of the current,— which also causes the positive or negative variation in the native electric current in the nerve; but electrotonus continues of the same strength as long as the circuit remains closed, even when the artificial current is weak. Dubois-Reymond, in order to point out the true signification of the electrotonus, reminds us of the proposition which Ritter and Erman had already advanced on the theory of convulsions, and thus discovered a law, partly from the after observations of Nobili, and partly from those of MM. Becquerel and Matteucci, namely, that the circumstance, or cause, producing motion, and arising at the moment the circuit is closed, is to be found in the electro-molecular change of the nerve, which is in effect an altered condition of the nerve; that, moreover, the activity of the applied current consists in placing the nerve in this condi- tion and maintaining- it so as long as the electric current is directed there; that finally, the opening convulsion is noth- ing else than the replacing of the nerve from the changed condition, back again into its natural state, as soon as the re- straint of the irritating current has been removed. From this, too, arose the aphorism of Ritter, " It is the organism, and no other, which produces on itself the opening shock." We are here also reminded of those ideas of Dr. Erman, that the essence of the inworking of the current consisted in produ- cing a more rapid chemical action in the tissues, i. e., a superior oxidation and hydrogenization in the one and the other half of the nerve; and also are we reminded how Nobili made a difference in the change brought about, by the up-running and by the down-running current, by terming it either " direct alter- nation," or " inverse alternation," in order to correspond with his explanation of the theory of convulsions. Dubois-Reymond goes on to say. If I am not entirely de- ceived, we are now enabled to fill up the theory of Nobili in a truly philosophic manner. It is my opinion, he says, — to the formation of which I think myself justified by facts, — that we