1. A dissertation on the sources of malignant bilious, or yellow fever, and means of preventing it: submitted to the examination of the Rev. John Ewing, S.T.P. provost ; the trustees & medical faculty, of the University of Pennsylvania, on the sixth day of June, 1799, for the degree of Doctor of Medicine Author(s): Chalwill, William G. Publication: Philadelphia : Printed by Way & Groff ..., 1799 Subject(s): Yellow Fever -- prevention & control