36 HISTORY OF ELECTRICITY. 



cently 14 described some important experiments and 

 measures ; but his apparatus was of such a kind that 

 the comparison of the results with the Coulombian 

 theory was not easy ; and indeed the mathematical 

 problems which Mr. Harris's combinations offered, 

 require another Poisson for their solution. Still 

 the more obvious results are such as agree with the 

 theory, even in the cases in which their author con- 

 sidered them to be inexplicable. For example, he 

 found that by doubling the quantity of electricity of 

 a conductor, it attracted a body with four times the 

 force; but the body not being insulated, would have 

 its electricity also doubled by induction, and thus 

 the fact was what the theory required. 



Though it is thus highly probable that the Cou- 

 lombian theory of electricity (or the J^pinian, which 

 is mathematically equivalent,) will stand as a true 

 representation of the law of the elementary actions, 

 we must yet allow that it has not received that 

 complete evidence, by means of experiments and 

 calculations added to those of its founders, which 

 the precedents of other permanent sciences have 

 led us to look for. The experiments of Coulomb, 

 which he used in the establishment of the theory, 

 were not very numerous, and they were limited to 

 a peculiar form of bodies, namely spheres. In 

 order to form the proper sequel to the promulga- 

 tion of this theory, to give a full confirmation, and 

 to ensure its general reception, we ought to have 



11 Phil Trans. 1834, P. 2. 



