THE steady decline in the mortality from tuberculosis has been interpreted as indicating that this disease would in the near future become one of minor significance. This implies that there is a definite ratio, such as was found in the Framingham study,1 between new cases of tuberculosis and deaths from the disease. Robins2 pointed out that prior to 1934 there had been no systematic effort made to determine the prevalence of tuberculosis in any large city in the United States and that in surveys made in New York City since 1934 the racial prevlaence of the disease has been found to be completely in discordance with the results anticipated from the application of standards based on mortality statistics. His study indicates that the mortality rate and the annual incidence rate are independent of each other and that the prevalence of clinically active tuberculosis is the resultant of the