We report the results of our studies on optical and thermal properties of two nonmesogenic compounds namely, dodecyl trimethylammonium chloride (DTAC) and Glacial acetic acid (GAA). The mixture exhibits very interesting schlieren texture of lyotropic micellar nematic phase, SmA and SmG phases, respectively, at different concentrations of DTAC sequentially when the specimen is cooled from its isotropic phase. The order parameter (S) of the lyotropic micellar nematic phase is estimated with the help of temperature dependence of optical anisotropy from the measured values refractive index and density data. The temperature variation of order parameter of the experimental curve is very well fitted with the Mayer-Saupe theoretical curve. Electrical conductivity has been discussed. The formation of above phases has been confirmed by optical and DSC studies.