In 1892, the physician and medical administrator Simon Flexner began research on cerebrospinal meningitis, a meningococcal disease with an untreated mortality rate between 70 and 90%. Experimenting on monkeys, Flexner developed a promising serum treatment for the disease by 1903, which he used extensively during the epidemic outbreaks of meningitis in New York City in 1904-1905 and 1907. For several years, Flexner kept his serum under his close supervision, with the result that the Rockefeller Institute became the primary source for knowledge about meningitis and its treatment. The 8 linear feet of Records amassed at the Rockefeller Institute between 1907 and 1913 document Simon Flexner's deployment of his serum treatment for cerebrospinal meningitis and his on-going interest in the epidemiology, etiology, and treatment of the disease. The collection consists largely of patient records, with data on hospitals and physicians to whom Flexner has dispensed his serum.