56 HISTORY OF MAGNETISM. 



cult to conceive these to be the traces of currents 

 of ethereal matter which circulate through the 

 magnet, and which are thus rendered sensible even 

 to the eye. When phenomena could not be ex- 

 plained by means of one vortex, several were intro- 

 duced. Three Memoirs* on Magnetism, written on 

 such principles, had the prize adjudged 3 by the 

 French Academy of Sciences in 1746. 



But the Cartesian philosophy gradually^ declined ; 

 and it was not difficult to show that the magnetic 

 curves, as well as other phenomena, would, in fact, 

 result from the attraction and repulsion of two 

 poles. The analogy of magnetism with electricity 

 was so strong and clear, that similar theories were 

 naturally proposed for the two sets of facts ; the 

 distinction of bodies into conductors and electrics 

 in the one case, corresponding to the distinction of 

 soft iron and hard steel, in their relations to mag- 

 netism. jEpinus published a theory of magnetism 

 and electricity at the same time (1759); and the 

 former theory, like the latter, explained the pheno- 

 mena of the opposite poles as results of the excess 

 and defect of a "magnetic fluid," which was dis- 

 lodged and accumulated in the ends of the body, 

 by the repulsion of its own particles, and by the 

 attraction of iron or steel, as in the case of induced 

 electricity. The /Epinian theory of magnetism, as 

 of electricity, was recast by Coulomb, and presented 

 in a new shape, with two fluids instead of one. But 

 3 Coulomb, 1789, p. 482. 



