98 HISTORY OF GALVANISM. 



Sciences, September the 18th, 1820 ; Oersted's dis- 

 coveries having reached Paris only in the preceding 

 July. At almost every meeting of the Academy 

 during the remainder of that year and the begin- 

 ning of the following one, he had new developements 

 or new confirmations of his theory to announce. 

 The most hypothetical part of his theory, the 

 proposition that magnets might be considered in 

 their effects as identical with spiral voltaic wires, 

 he asserted from the very first. The mutual attrac- 

 tion and repulsion of voltaic wires, the laws of 

 this action, the deduction of the observed facts 

 from it by calculation, the determination, by new 

 experiments, of the constant quantities which en- 

 tered into his formulae, followed in rapid succes- 

 sion. The theory must be briefly stated. It had 

 already been seen that parallel voltaic currents 

 attracted each other ; when, instead of being paral- 

 lel, they were situate in any directions, they still 

 exerted attractive and repulsive forces depending 

 on the distance, and on the directions of each ele- 

 ment of both currents. Add to this doctrine the 

 hypothetical constitution of magnets, namely, that 

 a voltaic current runs round the axis of each par- 

 ticle, and we have the means of calculating a vast 

 variety of results which may be compared with 

 experiment. But the laws of the elementary forces 

 required further fixation. What functions are the 

 forces of the distance and the directions of the ele- 

 ments ? 



