Addition from extranightcat
Similar thing can be done with mercury. A piece iron (a needle) is fixed close to mercury surface. Under sulfuric acid+dichromate the droplet pulsates, touching and bouncing off of Fe. In this case, the wicked thing called electrical double layer appears to define the droplet shape.
One more piece:
When a 10-11 percent solution of hydrogen peroxide is placed over a mercury surface, the latter becomes covered with a shining bronze-colored film and there is an evolution of oxygen gas which ceases periodically, there being 1-20 periods per minute, depending on the conditions. Traces of electrolytes have a very disturbing effect on the phenomenon, as do ether and olive oil, while alcohol does not prevent it. Electrical measurements against the calomel electrode showed an electromotive force of ca. 0.254 volt when the mercury was catalytically active and of ca. 0.322 volt when the mercury was catalytically inactive, the hydrogen peroxide electrode being cathode in both cases.
Bredig, G.; Weinmayr, J. Zeitschrift fuer Physikalische Chemie, Stoechiometrie und Verwandtschaftslehre (1903), 42 601