The recent report by Hoffman1on "Radium (Mesothorium) Necrosis" makes it necessary for us to report our unfinished observations on the danger of the accumulation of radioactive substances in the body and their effect on the hematopoietolytic systems.2Hoffman's contribution is based mainly on a survey, from the statistician's point of view, of some five deaths and twelve living cases, occurring among girls employed in painting the dials of watches and clocks with luminous paint. He found that they developed a very resistant infection of the jaw, with buccal lesions and marked anemia. His idea was that a distinct occupational poisoning had occurred, the paint entering the body by way of the gastro-intestinal tract as a result of the habit of pointing in their mouths the tips of the brushes used in painting. The recent illness and death of one of these patients gave us the opportunity, for