Floating Mercury on Water

WHILE trying, recently, a process for cleaning mercury, I obtained some small globules floating on water, in the same way that a waxed needle floats. The mercury had been shaken with sulphuric and chromic acids, and was finely subdivided; on pouring carefully into water, a few globules floated. Some of these ran together and coalesced, in deep depressions in the surface; the largest floating globule was about 0.5 millimetre diameter. The flotation was quite stable, and was not destroyed even by contaminating the surface with a drop of oleic acid, which spreads to a film reducing the surface tension to about 46 dynes per centimetre. The accompanying rough sketch (Fig. 1) shows the directions of the relevant surface tensions dotted in.