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Prof. D. E. Hughes. 



[May 19, 



form the ring or transversal magnetism into longitudinal magnetism 

 by strongly magnetising the wire after a current has passed through 

 it. This has the effect of rotating the whole of the molecules, and 

 they are all now symmetrical with longitudinal magnetism; then, by a 

 few torsions, the wire is almost as free as a new wire. I have 

 found this method more efficacious than heating the wire red hot, or 

 any other method yet tried. If I desire a constant current from 

 longitudinal magnetism, I place at one of the extremities of the wire 

 a large permanent magnet, whose sustaining power is 5 kilogrammes, 

 and this keeps the wire constantly charged, resembling in some 

 respects the effects of a constant current. The molecular magnetism 

 or the current obtained by torsion is not so powerful from this, my 

 strongest magnet, as that produced by the simple passage of a current, 

 being only 50 sonometric degrees in place of 70° for that due to the 

 passage of a current. The mere twisting of a longitudinal magnet, 

 without regard to the rotation of its molecules has no effect, as is 

 proved by giving torsion to a steel wire strongly magnetised, when 

 only traces of a current will be seen, perhaps one or two degrees, and 

 by using a constant source of magnetism or electricity, when no mea- 

 surable effect will be obtained. Evidently we have as much twisted the 

 magnetised steel as the soft iron. In the steel we have a powerful 

 masmet, in the soft iron a verv feeble one : still the molecular rotation 

 in iron produces powerful currents to the almost absolute zero of 

 tempered steel.* 



If we magnetise the wire whilst the current is passing, and keep 

 the wire constantly charged with both magnetism and electricity, the 

 currents are at once diminished from 70° to 30°. We have here two 

 distinct magnetic polarisations at right angles to each other, and no 

 matter what pole of the magnet, or of the current, the effect is greatly 

 diminished ; the rotation of the two polarities would now require a far 

 greater arc than previously. The importance of this experiment can- 

 not as yet be appreciated until we learn the great molecular change 

 which has really occurred, and which we observe here by simply 

 diminished effects. 



If we heat the wire with a spirit flame, we find the sounds increase 

 rapidly from 70 to 90, being the maximum slightly below red heat. I 

 have already remarked in my previous paper this increased molecular 

 activity due to heat, and its effects will be more clearly demonstrated 

 when w T e deal with the sounds produced by intermittent currents. 



Another method, by means of which I have again received proofs of 

 the rotation of the polarised molecules, is to pass an intermittent 

 current through a soft 0*5 millim. iron wire, listening to the results 

 by the telephone joined direct and alone to the coil, as described in 



* I purposely avoid using the terms " magnetic fluid " and "coercitive force." 



