Variation of electrical conductance and capacity of chemically pure MnO2in pressed powder form under a stress 6·0 × 1011dynes/sq. cm has been studied within the temperature range 26°c to 110°c at 1 MC/s, Electrical conductance of samples in tablet, form (3 mm thick and 15 mm in diameter) was measured between 26°C and 110°before and after heat treatment at 300°c for 36 hours. Capacitance values were also measured simultaneously within the above temperature range. Electrical conductance was found to attain a maximum at about 78°c. There is a marked hysteresis in ‘;lnconductance’ − 1 /Tgraph when measurements are made while temperature is rising and while falling.