A homologous series of 8-(4'-n-alkoxybenzoyloxy) quinolines were synthesized by established methods [5,6]. On evaluation by optical microscopy, none of the homologues were found to exhibit mesogenic behavior even in the monotropic condition. Then, each homologue (B) was mixed with a liquid crystal component (A) and binary systems were studied by optical microscopy. Solid-mesomorphic or isotropic-nematic transition temperatures of binary mixtures were determined and plotted to obtain the phase diagram for transition temperatures versus percentage composition of component (A). The nematic-isotropic transition curve was extrapolated to zero mole percentage of component (A) (100%B) to determine the latent transition temperature (LTT) of each nonmesomorphic homologue. The number of carbon atoms in the n-alkyl chain of each homologue versus LTT is plotted and a phase diagram is obtained. The isotropic-nematic transition curve behaves in a normal manner like a curve behaving for a typical nematogenic homologous series, including odd-even effects in its phase diagram. This method is useful to determine the probable temperature at which a nonmesogenic substance can show mesogenic behavior, provided a suitable condition is applied. Also, it is useful to correct the LTT of a homologue from the mesomorphic-isotropic transition curve.