In preceeding papers a model for the generation of charge carriers in organic liquids was developed. The activation energy of the dc-conductivity specific for one compound was said to be the sum of a resonance and a COULOMB part: E1 = E+½3 ET (the factor ½ is due to bimolecular recombination) . Measurements with aza-compounds show that E1 is decreasing linearily with increasing calculated π-electron-density at the N-atom. This fact argues for electrons to be the majority chargecarriers. E′ is the energy necessary to localize one electron at the N-atom for a short time, ET is the further separation-energy. With charge-transfer-complexes formed by acridine with aromatic hydrocarbons, E′ increases proportional to the electron-affinity of the hydrocarbons. For energetic reasons it can be assumed that the separated electron moves as a solvatised one through the liquid. An extrapolation shows that the proposed model holds for unsubstituted aromatic hydrocarbons too, but not for aliphatic ones. This is confirmed by experiments. Furthermore, arguments will be developed to distinguish between the conductivity specific for one compound and the conductivity due to impurities. In certain cases the impurity concentration can be estimated from the σ(1/T) curve.