Mr. DavT/'s Theory. 371 



altered by means of the galvanic apparatus, have at the 

 same time their chemical affinities also altered. Thus a body 

 which is naturally positive, but only in a low degree, will 

 have a very weak attraction for Oxygen, which is naturally 

 negative ; but exalt this naturally low positive state by 

 means of th* apparatus, and its attraction for oxygen shall 

 be strong in proportion : — for example, silver, which is na- 

 turally positive in a low degree, is incapable of acting upon 

 water j but if you exalt this natural state of electricity, by 

 means of the galvanic apparatus, it will become capable of 

 extracting the oxygen from it. 



" As a further illustration of the theory he stated, that if 

 the states of electricity of bodies which naturally were pos^ 

 sessed of strong chemical affinity were by means of the ap- 

 paratus entirely reversed, the consequence would be a dis- 

 union and destruction of the compound which they formed 

 in consequence of their natural affinities. 



" To prove this, the following experiment was performed : 

 -^-Moistened sulphate of potash was placed in the galvanic 

 circle, and presently it was decomposed ; potash appearing 

 at the negative and sulphuric acid at the positive side. This ' 

 effect is produced, says Mr. Davy, by the action of the gal- 

 vanic apparatus inducing a state of electricity in the sul- 

 phuric acid, the reverse of that which is natural to it, and 

 the same in the potash ; and in consequence these two sub- 

 stances, instead of combining, actually repel each other, and 

 are found on opposite sides of the vessel in which they were 

 placed in combination, the acid at the positive side and the 

 potash at the negative. 



" Mr. Davy seemed to rely much upon this experiment ; 

 but his explanation of it, if I did not much misunderstand 

 him, seems to militate against the doctrine he brought it 

 forward to support ; for he explained it upon this principle : 

 that the natural electricities of two bodies which were in 

 chemical union, being by means of the galvanic apparatus 

 reversed, they would, as a natural consequence, repel each 

 other, and thus be found in a separate state in the vessel in 

 which the compound was placed. 



"This experiment, as above explained, does not seem to 

 A a 2 afford 



