"he operations are proceeding in good faith.(b) In the event oil, gas, sulphur, or other minerals are discovered in paying quantities on any tract of land covered by a lease, then the lease as to that tract shall remain in force as long as oil, gas, sulphur, or other minerals are produced in paying quantities from the tract.(c) In the event of the discovery of oil, gas, sulphur, or other minerals" . . . . .