Thermodynamically, it is defined as the partial derivative of Gibbs free energy with respect to area at constant pressure and temperature, and it is related to temperature via the Eotvos equation.  
The Hay test for jaundice makes use of this property because bile can alter its value for urine.  Thermodynamically, it is defined as the partial derivative of Gibbs free energy with respect to area at constant pressure and temperature, and it is related to temperature via the Eotvos equation.  LaPlace's law relates the collapsing pressure of a spherical bubble to twice the value of this property, which is also the driving force of capillary action.  Measured in dynes per centimeter and explained by the cohesive forces between molecules with nothing above them, FTP name this quantity that can be lowered by surfactants and allows certain bugs to walk on water.
The Hay test for jaundice makes use of this property because bile can alter its value for urine.  
surface tension