  We study the quantum dynamics of neutral particle that posseses a permanent
magnetic and electric dipole moments in the presence of an electromagnetic
field. The analysis of this dynamics demonstrates the appearance of a quantum
phase that combines the Aharonov-Casher effect and the He-Mckellar-Wilkens
effect. We demonstrate that this phase is a special case of the Berry's quantum
phase. A series of field configurations where this phase would be found are
presented. A generalized Casella-type effect is found in one these
configurations. A physical scenario for the quantum phase in an interferometric
experiment is proposed.
