Correspondence (family and business), notebooks, essays, poetry, school notes, mathematical problems, business records, and other papers chiefly relating to scientific matters. Correspondence includes a letter from Joseph Priestley describing the making of phosphoric acid, letters written by Vaughan's mother Sarah referring to Priestley, a draft letter quoting Priestley's opinion on Benjamin Franklin's method of acquiring a style of writing, and 2 draft letters relating to scientific subjects.