1From Benjamin Franklin to Ingenhousz, 24 December 1783 (Franklin Papers)
ALS : Yale University Library I am greatly indebted to you for Letters. I shall write largely to...
2From Benjamin Franklin to Ingenhousz, 16 January 1784 (Franklin Papers)
ALS : New York Public Library; copy: Library of Congress I have this Day received your Favour of...
3From Benjamin Franklin to Jan Ingenhousz, 23 April 1784 (Franklin Papers)
ALS : Myron Kaller & Associates, Inc., Asbury Park, New Jersey (1989) I did intend to have...