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bilitj. Reasoning on the magnet as a source of electricity 

 in a paper "On the Physical Cliaracter of the Lines of 

 Magnetic Force " (Philosophical Magazine, s. 4, vol. III., 

 p. 415), he says, " Its analogy with the helix is wonderful, 

 nevertheless there is as yet a striking experimental distinc- 

 tion between them ; for whereas an unchangeable magnet 

 can never raise up a piece of soft iron to a state more than 

 equal to its own, as measured by the moving wire, a helix 

 carrying a current can develop in an iron core magnetic 

 lines of force of a hundred or more times as much power as 

 that possessed by itself when measured by the same means. 

 In every point of view, therefore, the magnet deserves the 

 utmost exertions of the philosopher for the development of 

 its nature, both as a magnet and also as a source of elec- 

 tricity, that we may become acquainted with the great law 

 under which the apparent anomaly may disappear, and by 

 which all these various phenomena presented to us shall 

 become oner Now, it was the precise and absolute manner 

 in which Faraday stated the definiteness of the relation 

 between the magnetism of a permanent magnet and that of 

 a piece of iron magnetised by its influence, that led the 

 author to enunciate in terms equally absolute and precise 

 the antithesis of Faradaj^'s proposition. How far Faraday's 

 hopes and preconceptions of the electro-magnet as a source 

 of electricity have been realized, the results described in this 

 and the author's former papers will show. Already has it 

 superseded the use of the voltaic battery in every electro- 

 depositing establishment of note in this country, and it is 

 making rapid progress abroad. 



That the transformation of mechanical energy into other 

 modes of force on so large a scale, and by means so simple, 

 will find new and much more important applications than 

 that above mentioned is one of the author's most firm con- 

 victions. 



In a note to his paper the author reviews the attempt by 



