In a previous issue ofThe Journal 1 we said that heretofore there were two indications for the treponema pallidum immobilization (TPI) test but that to these should be added a third. We recommended this test in the following situations: (1) to help distinguish between the biologically falsepositive and true-positive blood test for syphilis; (2) to assist in establishing a diagnosis of syphilis in patients who have clinical evidence of the disease, particularly in late syphilis, but who have negative blood and spinal fluid serologic tests; and (3) to assist in the diagnosis of syphilis in a patient with epidemiologic evidence of the disease but with negative clinical and serologic findings. As illustrative of the third indication, a case was presented wherein an 8-year-old boy, examined by us in 1955 because of a positive reaction to the Hinton test, proved on clinical examination to have congenital syphilis. However, his mother