adduced byVro?. 'Fav&day in support of DelaRive's Theory. 197 



are the same, except that they are very slow and small) it is 

 not a new acid stratum that comes to act upon the zinc ; yet 

 it will be a stratum of something which will take its place; 

 that is to say, which causes the chemical action exercised by 

 the liquid upon the zinc to take new vigour. I limit myself; 

 therefore, very willingly to the experiment esteemed by Prol 

 fessor Faraday "of itself convincing," in which there is no 

 doubt that when the liquid is agitated in the said circum- 

 stances these two facts follow,— the restoration of the chemical 

 action, and the strengthening of the current. 



But from both these phaenomena arising when the liquid is 

 agitated, does it follow immediately, as a necessary conse- 

 quence, that the second is occasioned by the first ? To ad- 

 mit this is to acknowledge that the chemical theory may be 

 proved independently of this experiment. Then this experi- 

 ment cannot be proclaimed " of itself convincing," because 

 some other is necessary to prove the truth of the theory of 

 M. de la Rive. 



V. If it is not of itself sufficient to demonstrate the truth 

 of the said theory, let us see if at least the aforesaid experi- 

 ment may serve to confirm it, on the hypothesis that it may 

 already be otherwise proved. 



The Delarivian theory being therefore supposed true, that 

 IS, It being supposed that the current in the voltaic pair be- 

 comes stronger, by the chemical action exercised by the liquid 

 upon the zinc, than upon the copper ; it is easily understood, 

 It IS true, how by renewing the acid stratum upon the surface 

 of the zinc, the current may be rendered more powerful. But 

 together with the zinc, the copper also is immersed in this li- 

 quid, and this metal is attacked itself also by the liquid; and 

 if proofs of this were wanted, the same chemical theory would 

 immediately furnish them ; because when copper is joined 

 with gold, plalina, charcoal, it becomes more highly electri- 

 cal. Then by stirring that liquid the chemical action upon 

 the copper is also increased, and this, if the theory of M. de 

 la Riye be just, must be to the injury of the current. 



Is it not possible that the trifling increase of power ob- 

 served on agitation, depends on the chemical action on the 

 copper being also increased in power, in consequence of which 

 the effect that is apparent is only that which is due to the ex- 

 cess of the increase of action on the zinc above that of the in- 

 crease of action on the copper ? Had this been the case it 

 would have been very easy to see it in the experiment I am 

 about to relate. 



VI. Instead of placing the two plates of the pair in the 

 same cup, I put the copper into one and the zinc into another; 



