John Fries Frazer was a prominent nineteenth-century scientist who made contributions to geology, including the connection of the aurora borealis with magnetic forces. Upon graduating from the University of Pennsylvania in 1833, Frazer went to work for Alexander Dallas Bache, under whom he had studied at the university. In 1836 Frazer was appointed to work as an assistant in the Pennsylvania Geological Survey. However, he left the study only a year later to pursue a legal education, following in the footsteps of his father. Frazer never entered legal practice, and instead began a long career as a professor and eminent academic. In 1844, upon Bache’s resignation from the University of Pennsylvania, Frazer was appointed to his former mentor’s post as a professor of natural philosophy and chemistry. Though he assumed a number of other roles, including acting provost, Frazer remained at the University of Pennsylvania, making significant contributions there until his death in 1872. Frazer was a founding member of the National Academy of Sciences and served for many years as the editor of the Journal of The Franklin Institute.