President of the Academy, 1891-1918 and head of the Pennsylvania Board of Health, his papers here mainly relate to the Academy. Playing an important role in the Centenary Celebration, his correspondence for that occasion is with local and state political and society personalities rather than with scientists, and is mainly placed with the Academy's Centenary Celebration papers. The letters in Dixon's file are concerned with other matters of a general scientific nature. Biographical details are included in the form of obituary news clippings.