During the past two years, numerous reports have appeared in the European literature regarding the action of para-aminobenzenesulfonamide (sulfanilamide) and its related compounds marketed under the proprietary names of Prontosil,1Prontylin and many other names, on both experimental and clinical infections with beta-hemolytic streptococci. Mice are protected or their survival periods significantly lengthened against many lethal doses of this organism by the administration of these drugs. The results of their use in clinical infections have been most striking. Colebrook1ahas reported a series of thirty-six cases of puerperal infection with hemolytic streptococci, treated with prontosil. From this he concluded that the drug caused a definitely beneficial effect, as evidenced by a prompt improvement in symptoms, a drop in temperature and a reduction in the death rate from between 18 and 28.8 per cent to 8 per cent in his series. The first American report was recently made by