1881.] 



Molecular Magnetism. 



217 



my paper of March 7. If the wire is then entirely free from strain, 

 we have silence, but a torsion of 20° produces some 50 sonometric 

 degrees of electric force. If, now (the wire being at zero strain), I 

 bring one pole of the permanent magnet I have already described 

 near the side of the wire, the sounds increase from zero up to 50°, 

 being at their maximum when this magnet is 5 centims. distant ; but 

 if we continue to approach the magnet the sounds gradually weaken 

 almost to zero. The explanation of this fact can be found when 

 we know that the greatest inductive effect on the wire would be when 

 a magnet is at an angle of 45° with the wire. And, also, considering 

 each molecule as a separate independent magnet, we find that at a 

 given distance for a given magnet the force of rotation is equal 

 to that of 45° ; by approaching the magnet we increase the rota- 

 tion but diminish the angular polarity in relation to the wire, hence 

 the decrease of force by the near approach of the magnet. And to 

 prove that the function of the elastic torsion is simply to rotate the 

 polarised molecules similarly to the magnet, we place the wire 

 under an elastic torsion of 20°, and approach gradually the magnet 

 as before. One pole now will be found to increase the sounds or its 

 angular polarity, the other will diminish them, until at 5 centims. dis- 

 tance, as before, we have perfect silence ; the torsion exists as before, 

 but the molecules are no longer at the same angle. On removing 

 the magnet we find that instead of the usual 50 of current we obtain 

 barely 5 or 10 : have we then destroyed the polarity of the molecules, 

 or do they find a certain resistance to their free rotation to their usual 

 place ? To solve this question we have only to shake the wire, or give 

 it a slight mechanical vibration, and then instantly the molecules rotate 

 more freely, and we at once find our original current of 50°. I will 

 forbear mentioning many other experimental proofs of my views by 

 this method, as there are many to relate by different methods in the 

 following sections. 



2. Influence upon the Molecular Structure of an Iron or Steel Wire of 



Electricity or Magnetism. 

 Being desirous to modify the apparatus already described, so that it 

 should only give indications of a current if it were of a spiral 

 nature, the wire was kept rigidly at its zero of strain or torsion, and 

 the coil was made so that it could revolve on an axis perpendicular to 

 the wire ; by this means, if the wire was free from strain, the centre 

 or axis of the coil would coincide with that of the wire. Thus, 

 with a straight copper wire, we should have a complete zero, but if 

 this wire formed a right or left-handed helix, the coil would require 

 moving through a given degree (on an arbitrary scale) corresponding 

 to the diameter and closeness of the spirals in the helix ; the degrees 

 through which the coil moved, were calibrated in reference to known 



Q2 



