Mr. G. Gore on Magnets and Electric Conductors. t 393 



It is impossible of belief that accompanying such a circumstance 

 there should be no measurable development of heat; and the 

 author's experiments have proved that in the above cases, at any 

 rate, the heat disengaged is very considerable — amounting, for in- 

 stance, on the part of cupric chloride, at least to about 2565 units 

 when 1 gram molecule of the crystalline salt is dissolved in its mi- 

 nimum of water at 16° C. and brought into contact with sufficient 

 to make the addition of 40 Aq. These numbers only roughly ap- 

 proximate to the truth. On diluting a solution of cobalt iodide 

 till the red colour appears, the thermal effect must be much greater, 

 as not only does it register several degrees on an ordinary thermo- 

 meter, but it may be perceived by the hand. 



The conclusions indicated by these results are obvious, but it is 

 beyond the scope of this paper to refer to them. The writer hopes 

 before long to complete his experiments with the view of having 

 them communicated to the E/oyal Society. 



" On the Attraction of Magnets and Electric Conductors." By 

 George Gore, P.B.S. 



Being desirous of ascertaining whether, in the case of two parallel 

 wires conveying electric currents, the attractions and repulsions 

 were between the currents themselves or the substances conveying 

 them, and believing this question had not been previously settled, 

 I made the following experiment : — 



I passed a powerful voltaic current through the thick copper wire 

 of a large electromagnet, and then divided it equally between two 

 vertical pieces of thin platinum wire of equal diameter and length 

 (about six or seven centimetres), so as to make them equally white- 

 hot, the two wires being attached to two horizontal cross wires of 

 copper. 



On approaching the two vertical wires symmetrically towards the 

 vertical face of one pole of the horizontally placed magnet, and at 

 equal distances from it, so that the two downward currents in them 

 might be equally acted upon by the downward and upward portions 

 respectively of the currents which circulated round the magnet- 

 pole, the one was strongly bent towards and the other from the 

 pole, as was, of course, expected ; but not the least sign of altera- 

 tion of relative temperature of the two wires could be perceived, 

 thereby proving that not even a small proportion of the current 

 was repulsed from the repelled wire or drawn into the attracted 

 one, as would have occurred had the attraction and repulsion taken 

 place, even to a moderate degree, between the currents themselves ; 

 and I therefore conclude that the attractions and repulsions of electric 

 conductors are not exerted between tlie currents themselves, bat between 

 the substances conveying them. 



Some important consequences appear to flow from this conclu- 

 sion, especially when it is considered in connexion with Ampere's 

 theory of magnetism, and with the molecular changes produced in 

 bodies generally by electric currents and by magnetism. 

 t As every molecular disturbance produces an electric alteration in 



