WS^ On Franklin's Theorif of Electricitj/^. [Mariom^ 



to induce an extravagant regard to some circumstances to thai 

 neglect of others equally or more important. Thus FrankliB|4' 

 whose experiments and observations will ever rank him among: 

 tlie first philosophers, has impeded the progress of science by hia- 

 hypothesis respecting electricity, which now, in spite of the* 

 anxious exertions of his old and most respectable disciples, seems 

 inevitably doomed to death. M. Van Marum however is gf fit 

 <iifferent opinion, and to arrest the progress of the dualists, by 

 -which he means those who think there are two electric fluids^ 

 by the assistance of the Royal Institution of the Sciences at 

 Amsterdam, he has throw A down the gauntlet to all the world, 

 in a paper read before that Institution in October, 1819, and ia 

 their name he has called for an answer to an experiment whiclt 

 he originally published in the year 1785, and considers still unan- 

 swered and unanswerable. 



The experiment which has been thus put forward as an expe- 

 rknentum crucis of the Franklinian hypothesis, is given so little 

 in detail, and so many of the important circumstances are omit- 

 ted, that it is difficult to deduce from it a perfect explanation of 

 the phenomena. From the whole of the statement, however, 

 the facts upon which M. Van Marum relies may perhaps be suf- 

 ficiently collected. It seems then, that in the formation and 

 collection of positive electricity, M. Van Marum employed two* 

 conductors ; one in more immediate connexion with the machine^ 

 which he has called the first conductor, and a second intended^ 

 to contain a larger quantity of electricity, which he calls th^ 

 receiving conductor, and this latter was placed at a little dist- 

 ance from the first conductor. It then appears, that he was 

 able to ascertain by the form of the spark, that the electric fluid 

 which was generated by the machine, and communicated to the 

 first conductor, passed from that conductor to the receiving, 

 conductor. 



Perhaps there cannot be shown in philosophical reasoningf*!!^ 

 lAore flagrant instance of the evil of an hypothesis and its per- 

 nicious influence over the mind, than that M. Van Marum and 

 his friends should esteem this " a most evident proof in favour 

 of the theory of Franklin." That is, because one electric fluid 

 can pass from one conductor to another, therefore there is no^ 

 other electric fluid. 



This experiment could satisfy only the most zealous adherents^ 

 of the Franklinian hypothesis ; but another, which is twice 

 detailed, is considered irresistible. It was so powerfully opera- 

 tive upon a French philosopher as to have silenced hiai for ten 

 years.* 



The material circumstances of this experiment can hardly b#" 

 gathered from either statement of it, but by comparing the two- 

 accounts together, the more important fact* inay probably b» 



• Ann, Phil, No. 96, p. 447. 



