Acute syphilitic meningitis has been recognized as a clinical entity since the year 1855,1 but it was not until 19022 that the changes in the spinal fluid of this disease were observed. Ravaut,3 writing in 1903, took the ground that syphilis in the secondary stage was a true septicemia, the skin and nervous system being principally affected. Whenever there were definite meningeal symptoms he found an increased number of lymphocytes in the spinal fluid.
The cytology of the spinal fluid was then studied rather extensively during the next ten years by the French writers. It was found that occasionally an increased number of lymphocytes was present in the spinal fluid, not only in the secondary stage of acquired syphilis, but also in hereditary syphilis (Tobler,4 Ravaut and Ponselle5). The increase in the number of lymphocytes was found whenever there were meningeal symptoms, but occasionally when