391' THIRD REPORT — l8So. 



in Electricity. In the first and second were developed the 

 theory and facts of magneto-electricity ; in the third, the 

 identity of voltaic, common, and other electricities, was proved, 

 so as to allow of the use of one for the other ; in the fourth, 

 a new law connected with the conduction and decomposition of 

 bodies was developed ; and in the fifth, by the application of 

 the third and fourth, an attempt is made to ascertain the true 

 nature of electro-chemical decomposition. 



This important part of chemical or electrical science has been 

 expressly treated of by different philosophers, and viewed in 

 various lights. The opinions formed of it differ very much 

 from each other, but agree generally in referring it to the at- 

 traction of the poles or metallic terminations of the pole, for 

 the principles either proximate or ultimate present in the de- 

 composing body. 



Having proved to his OM'n satisfaction that common elec- 

 tricity had the same power of effecting chemical decomposition 

 as that of the voltaic battery, and even shown that when mea- 

 sured out, a quantity of it does the same chemical work as an 

 ,equal quantity of voltaic electricity, Mr. Faraday resorted to 

 it for the purpose of taking advantage of its high intensity in 

 effecting decomposition under circumsitances in which the 

 voltaic battery would be quite inefficient, and so to accumu- 

 late facts and gain knowledge which might bear upon and 

 explain the usual mode of action of the latter. He found that 

 decomposition could be effected without the use of any poles, 

 or at least without the use of those metallic terminations usually 

 called poles ; for when salts and iodides were submitted to the 

 action of electricity, passing to and from them only through 

 the air, still decomposition took place. For instance, a piece 

 of paper being cut into a lozenge-shape, moistened with solution 

 of sulphate of soda, and placed between two points, one con- 

 nected with the electrical machine, and the other with a dis- 

 charging train, formed of a very extensive metallic system, 

 communicating with the ground, soon showed evidence of the 

 evolution of free acid and alkali, as the electricity of the ma- 

 chine passed through it, though it was two inches distant from 

 either of the points. The acid was evolved at that point where 

 the positive electricity entered the moistened paper, and the 

 alkali at that point where the electricity left the paper ; i. e. 

 considering the paper as a little conductor surrounded by air, 

 the acid was evolved at the negative extremity, and the alkali 

 at the 'positive extremity. Many other facts were referred to, 

 in which, as in this, air poles were successfully used; but the 

 word pole must in these researches be understood as having 



