1. An inaugural essay, on the eye, and on vision: submitted to the examination of the Rev. John Andrews ..., the Trustees and medical professors of the University of Pennsylvania, on the 5th day of June, 1805, for the degree of Doctor of Medicine Author(s): De Butts, Elisha, 1773-1831 Publication: Philadelphia : Printed for the author, by John H. Oswald, 1805 Subject(s): EyeVision, Ocular