  In Dirac's hole theory the vacuum state is generally believed to be the state
of minimum energy. However it has recently been shown that this is not the
case. In [1] it was shown that energy can be extracted from the hole theory
vacuum state through the application of an electric field so that the final
state has less energy than the vacuum state. In this paper we will confirm the
results of [1] by calculating the change in the energy of the vacuum state due
to its interaction with a specific electric field. It will be shown that the
final state has less energy than the original vacuum state.
