RECENTLY, the magnetic properties of molybdenite crystals have been studied in this laboratory at room temperaturer1 and also at both high and low temperatures2. It was then thought desirable to extend the investigations on this crystal to electrical conductivity. The electrical conductivity of single crystals of molybdenite has been measured by various workers3, but a more systematic study of the electrical properties was necessary in order to understand the nature of the carriers of the electric current in this crystal.