26 HISTORY OF ELECTRICITY. 



the action of gravitation." We may add, that by 

 forcing us upon this doctrine of the universal re- 

 pulsion of matter, the theory of a single fluid seems 

 quite to lose that superiority in the way of sim- 

 plicity which had originally been its principal re- 

 commendation. 



The mathematical results of the supposition of 

 ^Epinus, which are, as Coulomb observes 7 , the same 

 as of that of the two fluids, were traced by the 

 author himself, in the work referred to, and shown 

 to agree, in a great number of cases, with the ob- 

 served facts of electrical induction, attraction, and 

 repulsion. Apparently this work did not make its 

 way very rapidly through Europe ; for in 1771, 

 Henry Cavendish stated 8 the same hypothesis in a 

 paper read before the Royal Society; which he 

 prefaces by saying, " Since I first wrote the follow- 

 ing paper, I find that this way of accounting for 

 the phenomena of electricity is not new. ^Epinus, 

 in his Tentamen Theories Electricitatis et Magne- 

 tismi, has made use of the same or nearly the same 

 hypothesis that I have; and the conclusions he 

 draws from it agree nearly with mine as far as he 

 goes." 



The confirmation of the theory was, of course, 

 to be found in the agreement of its results with 

 experiment ; and in particular, in the facts of elec- 

 trical induction, attraction, and repulsion, which 

 suggested the theory. ^Epinus showed that such 

 7 Ac. P. 1788, p. 672. 8 Phil, Trans. 1771, vol. Ixi. 



