356 Mr. Farad ay on Magneto-electric Induction ; 



however, was even under these circumstances still maintained. 

 No difference was observed whether the oxygen was allowed 

 to escape as from a zincode of platinum, or was absorbed by 

 copper or zinc ; the metals, of course, being dissolved in pro- 

 portions equivalent to the hydrogen developed at the pla- 

 tinode. Solution of potassa, baryta, or strontia, similarly 

 treated, exhibited a transfer of about one-fourth of an equiva- 

 lent towards the platinode. 



These curious results are easily explained by supposing 

 that the solution is a mixture of two electrolytes ; with sul- 

 phuric acid they are H -f- (S 4- 4 O), oxysulphion of hydro- 

 gen (H + O) water; the current so divides itself that three 

 equivalents of water are decomposed, and one equivalent of 

 oxysulphion of hydrogen. Analogous changes occur with the 

 alkaline solutions, the alkaline metal passing as usual to the 

 platinode. 



LIII. On Magneto-electric Induction ; in a Letter to M, Gay- 

 Lussac. By Michael Faraday, D.C.L., F.R.S. 



[Continued from p. 289, and concluded.] 



T REPRESENTED this state of things under a general 

 -"* form, in the figures ij annexed to the memoir, which, as 

 to the arrows, the designation of the parts, &c. &c, I have 

 made to correspond, as well as I could, with fig. 2. plate iii. 

 of the Italian philosophers' memoir (plate ii.). I proceed to 

 show how it agrees with the galvanometrical results obtained 

 by them, and how far with their conclusions. 



With regard to the galvanometrical results, my figure 

 might be used instead of theirs, without occasioning any dif- 

 ference, and I have no reason to say that they are inexact. 

 Relatively to " one of those consequences," which arises from 

 " the immediate inspection of the arrows which mark the 

 currents in the two regions of the disc," or from any other 

 attentive and experimental examination, we see that the cur- 

 rents n, n, 77, on entering, instead of being in a contrary direc- 

 tion to those which are in the parts s s s, which recede, fol- 

 low exactly the same direction ; that is, that as to the general 

 movement near the pole they go from above below, or from 

 the circumference towards the centre, transversely to the lines 

 that the different parts describe in their course; and at a 

 great distance (F. 92.) on each side of the pole they are in 

 the contrary direction. In proportion to the nearness to the 

 pole of a part of the line described by a point, it is traversed 

 by a current, which commences, and increases in intensity 



