1. An inaugural dissertation on the chymical analysis and operation of vegetable astringents, with observations on the identity of the vegetable acids: sumbitted to the examination of the Rev. John Ewing, S.T.P. provost ; the trustees and medical professors of the University of Pennsylvania, for the decree of Doctor of Medicine Author(s): Willis, John, active 1795 Publication: Philadelphia : Printed by Alexander M'Kenzie, no. 129, Chesnut-Street, 1795 Subject(s): AstringentsVegetables -- chemistry