On June 29, 1932, a Negro girl, aged 7 years, was brought to the Harriet Lane Home at Johns Hopkins Hospital in an unconscious state and admitted there as a patient. The relatives reported that there had been a sudden onset of convulsions followed by stupor. Far across the city on July 25 another Negro girl, aged 10 years, was admitted to the pediatric service of the Provident Hospital in a stuporous condition, with a history of convulsions and intermittent unconsciousness for the previous four days. These two initial cases were followed by others that resulted in the unraveling of one of the most dramatic and fascinating medical and public health problems of recent years.By September 2, in both sections of the city, a total of forty cases of lead poisoning were discovered, chiefly among children, all in Negro families in which discarded storage battery casings had been used