of a century ago, before the medical students of the New York University; of course with no reference whatever to the present occasion. It was privately printed by the class for their own use, and has never before been given to the public. Its perusal cannot fail to sharpen the interest of readers to know more of the personality of the remarkable man who made the greatest of all chemical discoveries, and to whose eventful career there attaches so romantic an interest. The materials of the following sketch are compiled from the summary of Priestley's work given by Dr. Thomas Thomson, in his history of chemistry in 1829, and from the "Autobiography and Life of Priestley," published by his son in 1807.
Joseph Priestley was born in 1733, near Leeds, in Yorkshire, England. His father was a poor mechanic, a cloth-dresser, and his mother the daughter of a farmer. He was the eldest child, and, having lost his mother when six years of age, he went to live with his aunt, a woman in good circumstances, without children, and who adopted him. She was a dissenter, and her house was the resort of all the dissenting ministers in the country; and it is important to observe that, although a very religious woman, she was so thoroughly liberal as to welcome even the most unorthodox clergymen to her hospitality, and to encourage the widest latitude of opinion—a circumstance which probably determined the career of her nephew. Joseph was sent to a public school in the neighborhood, and at sixteen had made considerable progress in Latin, Greek, and Hebrew. He had thoughts of studying for a clergyman, but, his health failing, he turned his attention to trade, with the idea of settling in Lisbon as a merchant. This induced him to study the modern languages, and he learned French, Italian, and German, without a master. Recovering his health, he abandoned the business scheme, and resumed his former plan of becoming a minister. Having made some progress in mechanical philosophy and metaphysics, and dipped into Chaldee, Syriac, and Arabic, and learned a system of short-hand, in 1752 he was sent to the academy at Daventry. Here he spent three years, engaged keenly in studies connected with divinity, and wrote some of his earliest theological tracts. Freedom of discussion was admitted to its full extent in this academy, and the discussions among the students were conducted with perfect good-humor on both sides. Young Priestley, as he tells us himself, usually supported the heterodox opinion; but he never at any time, as he assures us, advanced arguments which he did not believe to be good, or supported an opinion which he did not consider as true.
When he left the academy, he settled at Needham, in Suffolk, as an assistant in a small, obscure dissenting meeting-house, at a salary of $150 a year. From the outset he was an original and independent thinker, and as a preacher he gave free and conscientious expression to the views he was led to adopt. It could hardly be otherwise than, that such a course would be distasteful to many people whose religion