Whilst the wire is subject to either volta-electric or magneto-electric induction, it appears to be in a peculiar state; for it resists the formation of an electrical current in it, whereas, if left in its common condition, such a current would be produced; and when left uninfluenced it has the power of originating a current, a power which the wire does not possess under common circumstances. This electrical condition of matter has not hitherto been recognised, but it probably exerts a very important influence in many, if not most, of the phenomena produced by currents of electricity. For reasons which will immediately appear, I have, after advising with several learned friends, ventured to designate it as the _electrotonic_ state. This peculiar condition shows no known electrical effects whilst it continues; nor have I yet been able to discover any peculiar powers exerted or properties possessed by matter whilst retained in this state. * * * * * This state is altogether the effect of the induction exerted, and ceases as soon as the inductive force is removed.... The state appears to be instantly assumed, requiring hardly a sensible portion of time for that purpose.... In all those cases where the helices or wires are advanced towards or taken from the magnet, the direct or inverted current of induced electricity continues for the time occupied in the advance or recession; for the electro-tonic state is rising to a higher or falling to a lower degree during that time, and the change is accompanied by its corresponding evolution of electricity; but these form no objections to the opinion that the electro-tonic state is instantly assumed. This peculiar state appears to be a state of tension, and may be considered as _equivalent_ to a current of electricity, at least equal to that produced either when the condition is induced or destroyed. Faraday further supposed that the formation of this state in the neighbourhood of a coil would exert a reaction upon the original current, giving rise to a retardation of it; but he was unable at the time to ascertain experimentally whether this was so. He even looked--though also unsuccessfully--for a self-induced return current from a conductor of copper through which a strong current was led and then suddenly interrupted, the expected current of reaction being “due to the discharge of its supposed electrotonic state.”