186 MR. FARADAY’S EXPERIMENTAL RESEARCHES IN ELECTRICITY. 
equatorial parts of the magnet instead of its polar extremity. On revolving’ 
the magnet screw fashion, the galvanometer needle was deflected in the same 
direction as before, bnt far more powerfully. Yet it is evident that the parts 
of the magnet from the equator to the pole were out of the electric circuit. 
228. Then the wire A was connected with the mercury on the extremity of 
the magnet, the wire B still remaining in contact with that in the jar (fig. 36.), 
so that the copper axis was altogether out of the circuit. The magnet was 
again revolved screw fashion, and again caused the same deflection of the 
needle, the current being as strong as it was in the last trial (227-), and much 
stronger than at first (226.). 
229. Hence it is evident that there is no discharge of the current at the 
centre of the magnet, for the current, now freely evolved, is up through the 
magnet ; but in the first experiment (226.), it was down. In fact, at that time, 
it was only the part of the moving metal equal to a little disc extending from 
the end of the wire B in the mercury to the wire A that was efficient, i. e. 
moving with a different angular velocity to the rest of the circuit (258.); and 
for that portion the direction of the current is consistent with the other results. 
230. In the two after experiments, the lateral parts of the magnet or of the 
copper rod are those which move relative to the other parts of the circuit, i. e. 
the galvanometer wires ; and being more extensive, intersecting more curves; 
or moving with more velocity, produce the greater effect. For the discal part, 
the direction of the induced electric current is the same in all, namely, from 
the circumference towards the centre. 
231. The law under which the induced electric current excited in bodies 
moving relatively to magnets, is made dependent on the intersection of the 
magnetic curves by the metal (114.) being thus rendered more precise and 
definite (217. 220. 224.), seemed now even to apply to the cause in the first 
section of the former paper; and by rendering a perfect reason for the effects 
produced, take away any for supposing that peculiar condition, which I ven- 
tured to call the electro-tonic state (60.). 
232. When an electrical current is passed through a wire, that wire is sur- 
rounded at every part by magnetic curves, diminishing in intensity according 
to their distance from the wire, and which in idea may be likened to rings 
situated in planes perpendicular to the wire or rather to the electric current 
