THE treatment of lupus by calciferol, described by Drs. G. B. Dowling and E. W. Prosser Thomas in the Lancet and noted in Nature of March 2, p. 260, is the subject of a comment by Dr. Jacques Charpy in the Lancet of March 16, p. 400. Dr. Charpy says that he has used similar treatment since 1941, and that he made his first report on twenty-seven subjects treated in this way on July 3, 1943 ; this form of treatment has been known in France since 1943 as the 'Charpy treatment'. Intolerance of the calciferol used in France has “hardly ever” been noted, because it is chemically pure and perhaps because it is made up in alcoholic solution and not in oil. Dr. Charpy says that lupus vulgaris has almost completely disappeared from France since 1941. Further information is given by Dr. Dowling in the Lancet (590, April 20, 1946).