Refractive indexes and densities of 4-propylphenyl trans-4-propylcyclohexyl-4-benzoate (TPCB) and trans-4-pentyl-(4'-cyanobiphenylyl-4)-cyclohexane (TPCC) are reported as functions of temp. in nematic re-entrant isotropic and isotropic phases. Mol. polarizabilities were evaluated by using Lippincott-δ-function potential model and order parameters evaluated by using an anisotropic internal field model Neugebauer approach). The sequences of phase transitions was confirmed by differential scanning calorimetric (DSC) studies. [on SciFinder(R)]