THEORETICAL OBSERVATIONS. 141 



fig. 50, the polar chain is composed of molecules of hydrochloric 

 acid, extending from the zinc to the porous division at a, and of 

 molecules of chloride of copper from a, to the copper plate. When 

 the Cl of molecule 1 unites with zinc, the H of that molecule unites 

 with the Cl of molecule 2 (as indicated by the connecting bracket 

 below) ; the H. of molecule 2 with the Cl of molecule 3 ; the Cu of 

 molecule 3 with the Cl. of molecule 4 ; and the Cu of this molecule 

 being the last in the chain, is deposited upon the copper plate ; 



Zinc. 



Copper. 



dilute sulphuric acid in contact with an amalgamated zinc plate, and 

 the same acid fluid saturated with sulphate of copper in contact with 

 the copper plate, are a combination of fluids of most frequent appli- 

 cation." 1 According to this theory, all the particles between the 

 zinc and copper during the action of the batteries will be performing 

 a whirling motion ; for, when the Cl of molecule 1 is liberated, the 

 H of 1 will combine with the Cl of 2, which compound molecule must 

 whirl round to be in its proper polar position, which will necessitate 

 that interchange distinctly referred to by Professor Faraday a 

 mutual transfer of the elements ; the Cl will pass towards the zinc 

 plate, and the H and Cu towards the copper plate. 



Danieil's and Miller's Views, Theories varying little from these 

 were held by the late Professor Daniell, till, by a series of interest- 

 ing experiments, in company with Professor Miller, he found that 

 there is no mutual transfer of the elements ; that the negative ele- 

 ment, or that represented above as Cl or SO 4 , is transferred from 

 the copper to the zinc, or in a decomposition cell from the negative 

 electrode to the positive electrode : but the positive element that 

 represented by H. or Cu is not transferred ; therefore, the theories 

 of Professors Faraday and Graham are opposed to a fundamental 

 truth experimentally proved. Professors Daniell and Miller con- 

 clude their paper, read before the Eoyal Society, by the following 

 observations : 



" These facts are, we believe, irreconcileable with any of the mole- 

 cular hypotheses which have been hitherto imagined to account for 

 the phenomena of electrolysis, nor have we any more satisfactory at 



1 Graham's Elements of Chemistry, 2d edition, 1849. 



