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Rh if I send this same current through the primary, I can hardly touch the wires coming from the secondary. The currents from the secondary are momentary in duration, and as they can be localised, they are used by physiologists as convenient stimuli for nerves and muscles.

Here is a large induction coil. You see the powerful discharges it gives, and when we send these through one of the late Mr. Warren de la Rue's vacuum tubes, containing a residue of carbonic acid, we get a magnificent luminous streak of quivering light in the tube, with beautiful transverse markings or bands.

A living being may be electrified positively or negatively and have no sensation caused by the electrification. You see here a frog sitting under this bell glass on a tin-plate connected with one of the dischargers of this large Wimshurst influence machine driven by an electric motor. The tin-plate and the frog's body are highly electrified, as you see by the sparks that fly out when I bring my finger near the tin-plate; but the frog is undisturbed so long as I do not touch it. We will not put it to the pain of having a tetanic spasm