The surgeon responsible for the care of a blistered burn has three decisions to make. First, he may or may not undertake to cleanse foreign material from the burn. Second, he must decide what to do with the blisters. He may leave them intact1; he may aspirate the fluid,2 or he may surgically unroof them.3 Third, he may expose the burn to the air or in some manner elect to dress it. The experiments to be described were designed to discover such differences in epithelization as may depend upon whether the blisters are aspirated, unroofed, or allowed to remain intact. Experiments The subjects were medical student volunteers. With the area under lidocaine (Xylocaine) hydrochloride anesthesia, burn blisters were produced by contact with the end of a weighted copper cylinder, 1 cm. in diameter, through which water from a thermostatically controlled bath vigorously recirculated. Twelve to sixteen burns