  Recent probing of H2O-D2O mixtures by various means (neutron deep-inelastic
scattering, Raman absorption, electrical H+/D+ conductivity) revealed an
unexpected dependence of the relevant physical quantities on the isotopic
composition of the mixture. We show that these observation can find their
physical rationale in the context of an approach to the physics of liquid water
which takes into account the non-negligible interaction of the molecules with
the electromagnetic field, from which a two-fluid micro- scopical picture of
water naturally emerges.
