480 Intelligence and Miscellaneous Articles, 



1. If two mercury electrodes, connected by the wire of a multi- 

 plier, be immersed one after the other in any liquid which is a con- 

 ductor of electricity (water, alcohol, glycerine, saline solutions, hy- 

 drochloric acid, &c), an electric current is observed, which goes 

 from the freshly wetted mercury-surface through the liquid to the 

 mercury-surface which has been wetted longest. 



2. The intensity of this current diminishes as the resistance of 

 the liquid column between the electrodes is increased. 



3. The electromotive force of the current varies according to the 

 nature and the concentration of the liquid, decreases as the concen- 

 tration of the saline solution increases, and may amount to 0*6 of 

 the electromotive force of a Daniell's element. 



4. The electromotive force is as much greater as the boundary 

 surface of mercury with the surrounding liquid on the later-im- 

 mersed electrode is more quickly produced. With increasing velo- 

 city of production of the boundary surface the electromotive force 

 approaches a maximum, which in the case of viscous fluids, like 

 glycerine, is very soon reached. 



5. The electromotive force stands in no relation to the quantity 

 of the capillary constant of the common boundary surface of mer- 

 cury and the surrounding liquid. 



6. The reason of these electrical currents is probably to be sought 

 in the alteration of the molecular condition (change of density or 

 concentration) which is gradually accomplished, in the particles of 

 the liquid in the vicinity of the surface of contact with the mer- 

 cury, after the wetting. 



7. Upon non-simultaneous wetting of solid metals by water and 

 other liquids, electrical currents ensue in like manner, and for the 

 same reason, as upon the non-simultaneous wetting of mercury. 



8. The electrical currents generated by the non- simultaneous 

 immersion of mercury electrodes in sulphuric acid, nitric acid, &c. 

 have their cause chiefly in the substances formed by chemical action 

 on the mercury ; they are therefore secondary phenomena, or che- 

 mical-polarization currents. 



9. As has long been known, the surface-tension of the common 

 boundary of mercury with other liquid conductors of electricity 

 may be altered by electrolysis. 



10. This alteration may consist in an augmentation or a dimi- 

 nution, and may change its sign with the direction and duration of 

 the electric current. 



11. The disturbances which occur in capillarity-phenomena can- 

 not be accounted for by substances electrolytically separated. 



12. Since accidental and unavoidable impurities considerably mo- 

 dify the amount of the surface-tension of mercury and other liquids, 

 it is not advisable to determine from that amount the quantity of 

 an electrolytically formed substance, or even to deduce from it 

 indirectly the intensity of electric currents or electromotive forces. 

 — Poggendorff's Annalen, vol. cliii. pp. 203-205. 



