Electro-physiology and electro-therapeutics : showing the best methods for the medical uses of electricity / By Alfred C. Garratt.
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2. That the native nerve and muscle current decreases -when the artificial constant current is made to run in the reversed direction. 3. That the native nerve and muscle current ceases to flow, while and as long as the nerve is disturbed, or is being excited, as by means of interrupted induction currents ; or by mechani- cal or chemical irritations that are strong enough to produce a motion or sensation. The last-mentioned oscillating or stagger- ing of the nerve current is by Dubois-Reymond termed the negative state, while the first-mentioned changes he terms the electro-tonic state of the nerves. The physiologic, and I may add the therapeutic signification of this electrotonus amounts to about this: That we see, after the application of the constant galvanic current, certain changes are produced in the nerve, parallel with, but to the one side, from the direct route of the applied artificial current. In this sense we see that the labors of Eckhard and others con- cur, by tracing the share of the physiological workings, that attend the galvanic excitement, as is done partly inside and partly outside the tested region. These observations of his may be found in the second volume of his works. Dr. Remak ob- serves, that these facts are so important to his mind " that they are the very starting point and stopping point for operations in all electro-therapeutics." The propagation of this electro-tonic state is doubtless arrested by the under-tying and then cut- ting through the nerve, and from this is proved that the pile- formed polarization of the nerve stands related to the " first cause " by which sensation and motion are produced. This view, deduced from all these facts, is also verified by another fact — that the electro-tonic condition of the nerves is developed under all those circumstances by which the action of the nerves appear visibly increased; and that this ends in con- tractions, that is, with the mechanically expressed capability of the nerves and muscles for action. This, however, by no means should lead us to mistake this electrotonus as one and the same thing, exactly as that natural circumstance or cause that produces sensation and contraction. This circumstance, or