160 DR. FARADAY'S EXPERIMENTAL RESEARCHES IN ELECTRICITY. (SERIES XIII.) 



positive and negative, bat on occasions in a most extraordinary manner, one being 

 charged with five, ten, or twenty times as much of both positive and negative elec- 

 tricity in equal quantities as another. At present, however, there is no known fact 

 indicating such states. 



1633. Even in cases of convection, or carrying discharge, the statement that the 

 current is everywhere the same must in effect be true (1627.) - for how, otherwise, 

 could the results formerly described occur ? When currents of air constituted the mode 

 of discharge between the portions of paper moistened with iodide of potassium or sul- 

 phate of soda (465. 469.), decomposition occurred; and I have since ascertained that, 

 whether a current of positive air issued from a spot, or one of negative air passed 

 towards it, the effect of the evolution of iodine or of acid was the same, whilst the re- 

 versed currents produced alkali. So also in the magnetic experiments (307.) whether 

 the discharge was effected by the introduction of a wire, or the occurrence of a spark, 

 or the passage of convective currents either one way or the other, (depending on the 

 electrified state of the particles) the result was the same, being in all cases dependent 

 upon the perfect current. 



1634. Hence, the section of a current compared with other sections of the same 

 current must be a constant quantity, if the actions exerted be of the same kind ; or 

 if of different kinds, then the forms under which the effects are produced are equiva- 

 lent to each other, and experimentally convertible at pleasure. It is in sections, there- 

 fore, we must look for identity of electrical force, even to the sections of sparks and 

 carrying actions, as well as those of wires and electrolytes. 



1635. In illustration of the utility and importance of establishing that which may 

 be the true principle, I will refer to a few cases. The doctrine of unipolarity as 

 formerly stated, and I think generally understood*, is evidently inconsistent with 

 my view of a current (1627.) ; and the later singular phenomena of poles and 

 flames described by Erman and others -{- partake of the same inconsistency of cha- 

 racter. If a unipolar body could exist, i. e. one that could conduct the one electricity 

 and not the other, what very new characters we should have a right to expect in the 

 currents of single electricities passing through them, and how greatly ought they to 

 differ, not only from the common current which is supposed to have both electricities 

 travelling in opposite directions in equal amount at the same time, but also from each 

 other ! The facts, which are excellent, have, however, gradually been more correctly 

 explained by BecquerelJ, Andrews §, and others; and I understand that Professor 

 OHiMS II has perfected the work, in his close examination of all the phenomena ; and 



* Ekmaw, Annales de Chimie, 1807. Ixi. p. 115. Davy's Elements, p. 168. Biot, Ency. Brit. Supp, iv. 

 p. 444. Becqxjerel, Traite, i. p. 167. De la Rive, Bib. Univ. 1837. vii. 392. 

 t Erman, Annales de Chimie, 1824, xxv. 278. Becquerel, Ibid, xxxvi. p. 329. 

 X Becquerel, Annales de Chimie, 1831. xlvi. p. 283. 

 § Andrews, Philosophical Magazine, 1836. ix. 182. 

 II Schweigger's Jahrbuch der Chemie, &c. 1830. Heft 8, Not understanding German, it is with extreme 



