TEARS OF WINE - THE STATIONARY STATE

Water-ethanol mixtures spontaneously produce strong convective effects , driving the liquid upward in thin films and downward in regular rows of drops known as ''tears of wine''. We present here a study of this stationary state, with a specific investigation of the interfacial ins tability which develops at the crossover between the reservoir and the thin film. We interpret it as a Rayleigh-like instability, the wavele ngth of which is mainly controlled by the extension of this crossover zone.