Soon after Dr. Priestley’s arrival in Pennsylvania, our Philosopher became personally acquainted with him, and presently conceived for his fellow-labourer in science a sincere esteem. This was reciprocal; and, therefore, while the celebrated English philosopher remained in Philadelphia, and also when he occasionally visited that city after his removal to the town of Northumberland on the Susquehanna, he passed much of his time in Dr. Rittenhouse’s family. So far as the pursuits of these gentlemen, in matters of science, were congenial—for, in some respects they were very dissimilar,—their opinions appeared to harmonize with each other: but, how far their sentiments accorded on other subjects, or whether at all, the Writer cannot undertake to pronounce; not possessing the necessary means to enable him to do so with a sufficient degree of certainty. Dr. Rittenhouse’s intercourse with Dr. Priestley, either personal or epistolary, was, however, of short duration; being terminated by the death of the former, in little more than two years after the latter first came to Philadelphia. One of the last interviews which Dr. Rittenhouse had with his friend Priestley, was very shortly before our philosopher’s death: he was one of a select few whom the writer had the pleasure of meeting at Dr. Rittenhouse’s, to dine, on the 18th of March, 1796. That learned and eminent foreigner,—for Dr. Priestley never became a naturalized citizen of the United States,—died at Northumberland in Pennsylvania, at an advanced age, on the 6th day of February 1804.