194 HISTORY OF CHEMISTRY. 



fractions for the simplicity of expression, the equi- 

 valent number or atomic weight of oxygen is 8, of 

 chlorine 36, of bromine 78.4, of lead 103.5, of tin 

 59, &c.; notwithstanding that a very high authority 

 doubles several of these numbers." 



Sect. 4. Reception of the Electro-chemical Theory. 



THE epoch of establishment of the electro-chemical 

 theory, like other great scientific epochs, must have 

 its sequel, the period of its reception and confirma- 

 tion, application and extension. In that period we 

 are living, and it must be the task of future his- 

 torians to trace its course. 



We may, however, say a word on the reception 

 which the theory met with, in the forms which it 

 assumed, anterior to the labours of Faraday. Even 

 before the great discovery of Davy, Grotthuss, in 

 1805, had written upon the theory of electro-che- 

 mical decomposition ; but he and, as we have seen, 

 Davy, and afterwards others writers, as Riffault 

 and Chompre, in 1807, referred the effects to the 

 poles 44 . But the most important attempt to ap- 

 propriate and employ the generalization which these 

 discoveries suggested, was that of Berzelius ; who 

 adopted at once the view of the identity, or at least 

 the universal connexion, of electrical relations with 

 chemical affinity. He considered 45 , that in all che- 



14 Faraday (Researches, Art. 481, 492). 

 45 Ann. Chim. Ixxxvi. 146, for 1813. 



