Effects due to Magnetization. 489 



we trace at once the magnetization of the point- electrode. 

 Since only the minute point was exposed to the liquid, it 

 wonld become saturated for comparatively small magnetizing 

 forces, and the curve indicates that this occurred at about 

 10,000 H., beyond which the curve becomes practically hori- 

 zontal. This further establishes the direct connexion between 

 this " throw " and the variation of the magnetization of the 

 exposed point, and confirms the explanation of Professor 

 Rowland, that it is due to the actual attraction of the magnet 

 for the iron, and not to any molecular change produced by 

 magnetization. 



(b) The indirect influence of the magnet caused by the 

 concentration of the products of the reaction about the more 

 strongly magnetized parts of the iron. 



This tends to produce a higher potential at the more 

 strongly magnetized parts, and finally establishes permanent 

 electric currents, which go in the liquid from the more 

 strongly magnetized to the neutral parts of the iron. 



This concentration-effect increases rapidly with the amount 

 of iron salts present and the fluidity of the solution. 



The convection-currents in the liquid are themselves a 

 consequence of this same concentration, being electromagnetic 

 rotations produced by the action of the magnet upon the local 

 electric currents between different parts of the iron. 



As to the permanent current due to the magnet which is 

 finally set up between the electrodes, as shown in fig. 1 (II.), it 

 is probably owing to a change in the character of the reaction 

 produced by the concentration of the iron salts about the more 

 strongly magnetized parts, which would tend to cause a 

 ferrous instead of a ferric reaction to take place, and thus 

 increase the electromotive force. 



Physical Laboratory, Johns Hopkins University, 

 May 1892. 



Note. — Since the completion of the above investigation, a 

 number of experiments have been performed similar to those 

 of Professor Remsen. Starting with the known existence 

 and direction of the electric currents in the liquid, it was 

 thought that these might lead to some explanation of the 

 peculiar form of deposit in equipotential lines. A number of 

 interesting facts have been noted, but they are withheld for 

 further experiments. Gr. 0. S. 



Phil. Mag. S. 5. Vol. 35. No. 217. June 1893. 2 M 



