1. Observations on the means of improving the medical police of the City of New-York: delivered as an introductory discourse, in the hall of the College of Physicians and Surgeons, on the sixth of November, 1820 Author(s): Hosack, David, 1769-1835 Publication: [New York? : s.n., 1820?] Subject(s): Public HealthYellow FeverNew York City