Bancroft rule

The Bancroft rule states: 'The phase in which an emulsifier is more soluble constitutes the continuous phase.' The Bancroft rule states: 'The phase in which an emulsifier is more soluble constitutes the continuous phase.' It was named after Wilder Dwight Bancroft, an American physical chemist, who proposed the rule in the 1910s . In all of the typical emulsions, there are tiny particles (discrete phase) suspended in a liquid (continuous phase). In an oil-in-water emulsion, oil is the discrete phase, while water is the continuous phase.