Mr. Hopkinson held an appointment in the Loan-office of Pennsylvania, for some years. He afterwards succeeded George Ross, Esq. in the office of Judge of the Admiralty, for that state. In this station he continued until the year 1790; when President Washington, by whom he had the honour to be much esteemed, conferred on him the place of Judge of the District Court of the United States, for Pennsylvania: which important office he held during the remainder of his life. A collection of Judge Hopkinson’s writings, on various subjects, was made after his death, and published in the year 1792, in three octavo volumes; constituting a curious and entertaining miscellaneous work. He died on the 8th of May, 1791, in the fifty-third year of his age, and somewhat more than five years before his venerated friend, Rittenhouse. Mr. Hopkinson was one of the executors of Dr. Franklin’s Will; but he survived the Doctor little more than a year. Footnote 245: Belonging to the Library Company of Philadelphia, and to the American Philosophical Society. ----- “TH. JEFFERSON sends to Mr. Rittenhouse Bishop Watson’s essay on the subjects of chemistry, which is too philosophical not to merit a half an hour of his time, which is all it will occupy. He returns him Mr. Barton’s papers[246], which he has perused with great pleasure; and he is glad to find the subject has been taken up by so good a hand: he has certainly done all which the scantiness of his materials would admit. If Mr. Rittenhouse has done with the last number of the Journal de Physique, sent him by Th. J. he will be glad to receive it, in order to forward it on to Mr. Randolph: if not done with, there is no hurry. “Monday morning.” ----- Footnote 246: The papers, referred to by Mr. Jefferson, were “Observations on the probabilities of the Duration of Human Life, and the progress of Population, in the United States of America;” addressed, in the form of a Letter, to Dr. Rittenhouse, Presid. of the Am. Philos. Society, and afterwards published in the third volume of the Society’s Transactions. ----- --- The relation in which Dr. Rittenhouse now stood to the American Philosophical Society, of which he had attained to the honour of being the President, renders it proper that some account should be given, in this place, of an institution heretofore distinguished by its Transactions. The following are the leading features in its history.