1. An inquiry into the causes and nature of the yellow fever: submitted to the examination of the Rev. John Ewing, S.T.P. provost, the trustees and medical professors of the University of Pennsylvania, on the sixth day of June, 1799, for the degree of Doctor of Medicine Author(s): Watts, Washington. Publication: Philadelphia : Printed by John Ormrod, no. 41, Chesnut-Street, 1799 Subject(s): Yellow Fever