In their recent cooperative study on penicillin in the treatment of 500 infections, Keefer and his associates1 stated that "experimentally it is a potent agent in gas bacillus infections, but up to the present time there are no studies on human cases." The comparatively rare occurrence of this important war infection in civilian life determines us to report a preliminary contribution. We observed a severe gas infection in a 7 year old girl. After all routine measures, including serums, sulfonamides and amputation, had failed, Dr. Chester Keefer2 provided us with penicillin in sufficient quantities to treat successfully the patient, whose outlook seemed hopeless. The isolation of our mountain hospital made it unprepared and unequipped to furnish exhaustive laboratory studies. The clinical significance of our observation, however, remains important enough to justify more investigations of this treatment. REPORT OF CASE Y. T., a girl aged 7 years, of normal