“Ninety-seven letters addressed to Josiah Wedgwood, Sir Joseph Banks, Capt. James Keir, James Watt, Dr. William Withering, Dr. Benjamin Rush, and others. Together with an appendix: I. The likenesses of Priestley in oil, ink, marble, and metal. II. The Lunar society of Birmingham. III. Inventory of Priestley's laboratory in 1791.”