Fothergill writes to an English physician, J. Woodforde, from Bath and Bristol in England and from Philadelphia. The letters concern their common interests in medicine, with comments on current events, American and Philadelphia society, and medicine in the United States.

These letters of American Philosophical Society members and prominent early American scientists were selected from Carson's extra-illustrated draft of "A History of the Medical Department of the University of Pennsylvania" (Philadelphia, 1869).