ERRONEOUS diagnoses of neurosyphilis are sometimes made in cases of neurologic syndromes because of a history and serologic evidence of syphilis and the presence of abnormalities in the cerebrospinal fluid. It is generally recognized that examination of the cerebrospinal fluid is essential for the diagnosis of neurosyphilis. As shown in a previous report,1 the reagents and procedures used in such tests should be quantitatively standardized in order to yield accurate and reproducible results. They should include a cell count, determination of total protein and a colloidal gold test of the cerebrospinal fluid, as well as quantitative complement fixation tests of both the cerebrospinal fluid and the blood.2 Furthermore, the results of the tests of the cerebrospinal fluid should have a quantitative relation to each other, so that together they form a syndrome reflecting the activity and character of the syphilitic inflammatory process. The result of each test should