1From Benjamin Franklin to Joseph Priestley, 19 September 1772 (Franklin Papers)
ALS (letterbook draft) and copy: Library of Congress In July, 1772, Lord Shelburne asked...
2From Benjamin Franklin to Joseph Priestley, 4 May 1772 (Franklin Papers)
ALS (draft): American Philosophical Society I think with you that there cannot be the least...
3From Benjamin Franklin to Joseph Priestley, 10 April 1774 (Franklin Papers)
Printed in Joseph Priestley, Experiments and Observations on Different Kinds of Air … (3 vols.,...
4From Benjamin Franklin to Joseph Priestley, [July 1772]: extract (Franklin Papers)
Extract: printed in Joseph Priestley, “Observations on Different Kinds of Air,” the Royal...