In an earlier paper on this subject, it was conjectured that if temperatures of H2O and D2O are scaled according to their temperatures of maximum density, then the structural properties of these two liquids should be very closely the same. In this paper it is found that the idea is valid for the densities within the four decimal point experimental precision of the D2O data. If this structural effect is not taken into account, a comparison of properties, such as viscosities or self-diffusion coefficients, of isotopic liquid water would have a reduced meaning. Comparing data at the same temperature, as has traditionally been done, simply gives rise to misleading isotope effects.