396 THIRD REPORT — 1833. 



electro-chemical decomposition advanced by others, as far as 

 they could be gathered from their published papers. 



Grotthuss published on the subject in the year 1805. He 

 considers the pole as an attractive agent ; the poles have at- 

 tractipe and rejiellhig powers : the negative pole attracts 

 hydrogen and repels oxygen, whilst the positive pole attracts 

 oxygen and repels hydrogen. The powers of each pole upon 

 any one pai'ticle are inversely as the squares of the distances; 

 hence giving, as he says, (though erroneously,) for any one 

 particle, a constant force. He first put forth the view of suc- 

 cessive decompositions and recompositions, and so explains 

 the appearance of the elements at a distance from each other. 

 He thinks the elements about to separate at the poles, unite 

 to the two electricities there, and so become gases*. 



Sir Humphry Davy wrote on the subject in 1806. His ex- 

 pressions are very general, so as to accord with many specific 

 views of decomposition ; but when more particular, he refers 

 the decomposing effects to the attraction of the polesf . He 

 agrees with Grotthuss in supposing successive compositions and 

 decompositions throughout the fluid; supposes that the attrac- 

 tive and repellent agencies may be communicated from the 

 metallic surfaces throughout the whole of the menstruum, being 

 communicated from one particle to another particle of the same 

 kind, and diminishing in strength from the place of the poles 

 to the middle part, which is necessarily neutral. In 1826, Sir 

 Humphj-y Davy said he had nothing to alter in the fundamental 

 theory just referred to, and uses the terms attraction and re- 

 pulsion in the same sense as before. 



MM. Riffault and Chompre in 1807 came to the conclusion 

 that not merely decompositions, but actual separations of the 

 elements took place throughout the whole of the humid con- 

 ductors. They consider the negative current as coUectiilg and 

 cai'rying the acids, &c., to the positive pole, and the positive 

 current as doing the same thing with bases, leaving them at 

 the negative pole. 



M. Biot speaks vei'y philosophically and cautiously, but refers 

 the effects to the attraction and repulsion exerted by the poles 

 and the parts in their vicinity. He does not appear to admit 

 the successive recompositions and decompositions of Grotthuss 

 and Davy, but seems to consider the particles under transfer 

 as attached for the time to the electricity, and carried on by it. 



* Atinales de Chiwie, 1806, torn. Iviii. p. 64. 



\ Philosophical Transactions 1807, pp. 28, 29, .30 ; Elements nf Chemical 

 rhilosophy, p. 160. 



