  We have studied the real part of the dielectric constant of water from 100 Hz
to 1 MHz. We have found that there is a frequency where the dielectric constant
is independent of temperature, and called this the isopermitive point. Below
this point the dielectric constant increases with temperature, above, it
decreases. To understand this behavior, we consider water as a system of two
species: ions and dipoles. The first give rise to the so called
Maxwell-Wagner-Sillars effect, the second obey the Maxwell-Boltzmann
statistics. At the isopermitive point the effect of both mechanisms in the
dielectric response compensate each other.
