-J4 HISTORY OF GALVANISM. 



wire of a voltaic circuit, acts upon a magnetic needle ; and thus re- 

 called into activity that endeavor to connect magnetism with electri- 

 city, which, though apparently on many accounts so hopeful, had 

 hitherto been attended with no success. Oersted found that the needle 

 has a tendency to place itself at right angles to the wire ; a kind of 

 action altogether different from any which had been suspected. 



This observation was of vast importance ; and the analysis of its con- 

 ditions and consequences employed the best philosophers in Europe 

 immediately on its promulgation. It is impossible, without great in- 

 justice, to refuse great merit to Oersted as the author of the discovery. 

 We have already said that men appear generally inclined to believe 

 remarkable discoveries to be accidental, and the discovery of Oersted 

 has been spoken of as a casual insulated experiment. 1 Yet Oersted had 

 been looking for such an accident probably more carefully and perse- 

 veringly than any other person in Europe. In 1807, he had pub- 

 lished 2 a work, in which he professed that his purpose was " to ascer- 

 tain whether electricity, in its most latent state, had any effect on the 

 magnet." And he, as I know from his own declaration, considered 

 his discovery as the natural sequel and confirmation of his early 

 researches ; as, indeed, it fell in readily and immediately with specu- 

 lations on these subjects then very prevalent in Germany. It was an 

 accident like that by which a man guesses a riddle on which his mind 

 has long been employed. 



Besides the confirmation of Oersted's observations by many experi- 

 menters, great additions were made to his facts : of these, one of the 

 most important was due to Ampere. Since the earth is in fact mag- 

 netic, the voltaic wire ought to be affected by terrestrial magnetism 

 alone, and ought to tend to assume a position depending on the 

 position of the compass-needle. At first, the attempts to produce 

 this effect failed, but soon, with a more delicate apparatus, the result 

 was found to agree with the anticipation. 



It is impossible here to dwell on any of the subsequent researches, 

 except so far as they are essential to our great object, the progress 

 towards a general theory of the subject. I proceed, therefore, imme- 

 diately to the attempts made towards this object. 



See Schelllng ueber Faraday's Entdeckuny, p. 27. 2 Ampere, p. 69. 



