I do hereby certify whom it may concern, that I had some Acquaintance with Mr John Ruston, who was formerly concern’d in the Principio Iron Works in Maryland, and more with Mr Job Ruston who settled in Chester County, Pennsylvania, and that I always understood them to be Father and Son: And that I have known Mr Thomas Ruston (now Dr Ruston) from a Boy;—in this Country while an Apprentice to Dr Bond;—in England when improving himself in the Study & Practice of Physick;—and afterward in France when he was about returning hither; and that I always understood him to be the Son of Mr Job Ruston, having never heard it call’d in question. Given under my Hand and Seal at Philadelphia, this 9th Day of June 1789.