Experimental Researches in Electricity. 105 



decomposition was in progress. Acids were passed through 

 alkaUes, and alkahes and earths through acids, so that the 

 distinctive properties of each seemed temporarily destroyed. 

 In no particular does the theory of Faraday contrast more 

 favourably with its predecessors than in this, since accord- 

 ing to his views, what was formerly an unintelligible wonder^ 

 becomes an essential condition, and it appears that the more 

 alkali there is in the course of an acid, the more is the 

 transfer of the latter facilitated from pole to pole, " and 

 perhaps," he adds, " a better illustration of the difference 

 between the theory I have ventured, and those previously 

 existing, cannot be offered than the views they respectively 

 give of such facts as these." 



As a general consequence of the preceding, it may be 

 stated, that the more directly bodies are opposed to each 

 other in chemical affinity, the more ready is their separa- 

 tion from each other in cases of electro-chemical decom- 

 position, i. e, provided other circumstances, as insolubility, 

 deficient conducting power of their proportions, do not in- 

 terfere, and hence it is possible that failure in producing 

 decomposition may arise not from the strength, but from the 

 weakness of the affinity which holds bodies together. 



In concluding his fifth section, Faraday makes a few re- 

 marks on what are usually called the poles of the battery. 

 " These," he states, " are merely the surface or doors by 

 which the electricity enters in or passes out of the substance 

 suffering decomposition. They limit the extent of that sub- 

 stance in the course of the electric current, being its termi- 

 nations in that direction : hence the elements evolved pass 

 so far, and no farther. 



" Metals make admirable poles, in consequence of their high 

 conducting power, their immiscibility with the substances ge- 

 nerally acted upon, their solid form, and the opportunity of 

 selecting such as are not chemically acted upon by ordinary 

 substances. 



p 



