Joseph Priestley, known as a scientist, preacher and teacher, was an English friend and colleague of Franklin's. He is best known for his isolation of oxygen and the other distinct gases that make up the air around us. He experimented with the isolation of carbon dioxide, succeeded in adding it to water in order to produce aerated or carbonated water, and advanced the understanding of the process of respiration.
His radical political views (he supported both the American and the French Revolutions) led to his flight from England after rioters attacked his home in 1791. He came to the United States and settled in rural Pennsylvania where he spent the last decade of his life. (Information obtained from the Chemical Heritage Foundation and other general sources.)
Priestley authored two works on electricity. According to Dr. Frank Shoemaker, Professor Emeritus of Physics at Princeton University, the University's Firestone Library owns first edition copies of both. The earlier is inscribed, "Presented to the Publick Library of the College of New Jersey, Benjamin Franklin, F.R.S."