1820.] Franklin's Theory of Electricity. 445 



Among these, M, Coulomb was the first who began to readmit 

 the old hypothesis. He wrote two prohx memoirs respecting 

 the manner in which the electric power distributes itself through 

 several conductors, and on many subjects of an analogous 

 nature there are to be found in the Memoires de I'Academie 

 Royale des Sciences, 1786, 1789, and these inquiries appear to 

 have led him to reasons for returning to the old system, in 

 favour of which, however, he has neither alleged experiments, 

 nor refuted the observations supporting the contrary system. 

 Since this period many French philosophers have adopted the 

 opinion of Coulomb, of which M. Libes gives the following 

 account.* " Coulomb considers the electric fluid as composed 

 of two particular fluids, which are neutrahzed by each other in 

 the ordinary state of the bodies, and which separate themselves 

 when the bodies are electrified. The first, produced by the 

 friction of glass, is called vitreous fluid, or vitreous electricity. 

 The other which is furnished by resin, silk, sulphur, wax, &c. is 

 named resinous fluid, or resinous electricity. Thus vitreous elec- 

 tricity answers to Franklin's positive electricity, and the resinous 

 to what he designated as negative electricity." 



In 1802, Abbe Haiiy, who had then acquired much celebrity 

 by his treatise on Mineralogy, published the preceding year, was 

 charged by Buonaparte, at that time First Consul, to compose 

 within a few months an elementary work on physics for the use 

 of the masters in the Lyceums, for which a new plan of instruc- 

 tion was then forming. M. Haiiy, being obliged to comply with 

 this order in a very short space of time, although mineralogy 

 rather than physics had for a long while been his favourite pur- 

 suit, admitted into his work the theory supported by Coulomb ; 

 that is to say, of two fluids, in order to explain electrical pheno- 

 mena, without at all considering what has been alledged as 

 evident proof in favour of the Franklinian system, or at least 

 without making any reflections, much less any observations, 

 tending to refute it. Since the publication of this work in 1802, 

 and its being universally employed as a work of instruction in 

 the Lyceums of France, the theory here laid down has been 

 generally adopted in that country ; that is to say, the theory of 

 two entirely different fluids, one vitreous, the other resinous. 



Having several times had occasion to converse with French 

 philosophers, I am persuaded that the prejudice since that time so 

 popular among the chemists and philosophers of that country, in 

 favour of the dualism, or system of two electric fluids, ought, in 

 a great measure, to be attributed either to their not recollecting, 

 or to their not being acquainted with the observations which, 

 had been since made, and which tended to overthrow that sys- 

 tem. I recollect among others the result of a conversation which 

 I had on the subject with a French philosopher, known by hi» 



* Trait6 Elemeotaire de Pb}>sique, Paris, 1801, torn. iii. p. 276. 



