THE PRODUCTION OF PERSISTENT ALOPECIA IN RABBITS BY ROENTGEN RADIATION; A STUDY OF THE MINIMUM DOSE REQUIRED AND THE CONSISTENCY OF THE REACTION

Seven areas on the abdomen of each of fourteen rabbits were exposed to soft Roentgen radiation of constant quality in doses varying, in the region of the value critical for the production of persistent alopecia, by regular steps of about 4 per cent. Without exception the critical dose was found to lie between two such values, the upper limit being represented by exposures on eight of the animals and the lower on ten of them. With certain reservations, the critical dose corresponds to the production of 2.04 x 10¹⁵ ions of either sign per gm. of tissue.