“…Through this apertui'e only a circular area of 0-5 centimetre diameter receives the radiation (MacKee, Mutcheller and Cipollaro, 1943} and only approximately 600 r, or half the dose as measured in air, is received by the core (Goldberg, 1944). Thus the core of the wart receives 2200 r, and although this would appear to be a large single dose, the area is so small that the risk of later damage is negligible as tissue injury effect (Belisario, 1942) and backscatter are practically eliminated and any possible later irradiation sequelee could easily be removed surgically. So far no aubsequeut effeets have been observed.…”