Surface Tension Gradient Explanation of Dissolution This illustration shows the effects of a perturbation of the liquid-liquid interface. Without an instability the drop would dissolve uniformly as on the left. However, if one side of the drop becomes indented more alcohol is dissolved into the water in region B relative to region A. This higher concentration of alcohol lowers the relative surface tension and the drop moves away from B and toward A. This continues until the molecular bonds are overcome by the surface tension gradient force. This results in the “Boomerang Breakup.”