240 



of any fixed magnetic poles,, but from the repulsion of 

 these currents, as is the case with the wire. 



It has been found that wires, freely suspended, along 

 which currents were passing in opposite directions, 

 revolve about each other, or have an inclination to 

 place themselves at right angles ; thus exhibiting the 

 same phenomenon as the magnet and the conducting 

 wire. So far the hypothesis of Ampere leads us most 

 satisfactorily. We see in the magnet one form of 

 electricity, and in the machine or battery another. But 

 why should not the electricity of the magnet, electricity 

 at rest, exhibit the same powers as this force in 

 motion ? 



Oersted, whose theory led him to the discovery of the 

 fact of the magnetic power of an electric current, of the 

 establishment indeed of the new science ELECTRO- 

 MAGNETISM, regards the phenomena of a current passing 

 a wire, and its action on a needle, as evidence of two 

 fluids, positive and negative, traversing in opposite 

 directions, and mutually attracting and repelling. He 

 conceives that they pass the wires in a series of spirals ; 

 that in the magnet, by some peculiar property of the 

 iron, this conflict of the currents is reduced to an equili- 

 brium, and its power becomes manifested in its attractive 

 force.* This does not, however, convey a clear idea to 

 the mind. 



It is curious that iron becomes magnetic in a superior 

 degree to any other metal ; that steel retains perma- 

 nently any magnetism imparted to it; but that soft 

 iron rapidly loses its magnetic power. This must be in 

 virtue of some peculiar arrangement of the molecules, 

 or some unknown physical condition of the atoms of the 

 mass, by which a continued influence is retained by the 

 steel, probably in a state of constant internal circulation. 



* Experience Electro-Magnetique . par M. CErsted. Ann ales 

 de Chimie, vol. xxii. p. ^01. De la Rive, Recherches sur la Distri 

 button de I'Electricite dyn. duns les Corps. Geneve, 1825. 



