During the past decade there have been two material advances in the treatment of patients suffering from Addison's disease. The first of these was the recognition of the abnormalities of electrolyte metabolism present in addisonian patients and the correction of these disturbances primarily through the addition of large amounts of sodium salts to the diet1and also through a reduction in the intake of potassium.2The second advance came through the elaboration of extracts of the adrenal cortex,3which are life sustaining, at least in adrenalectomized animals. Despite the progress made through these contributions, the treatment of Addison's disease has continued to be only moderately satisfactory at best. In the past three years the isolation of a series of crystalline steroids of great physiologic activity from adrenal cortical material has been accomplished by Kendall,4by Wintersteiner and Pfiffner5and by Reichstein.6This work aroused