The work necessitated much correspondence with Franklin and others of his philosophical friends in London, and much of his leisure was devoted to his own experimental observations. Nevertheless, the book was completed in less than a year. Hasty and imperfect as it was, “_The History and Present State of Electricity_. With Original Experiments, illustrated with Copperplates,” was well received and ran through five editions in its author’s lifetime. Its publication at once stamped Priestley as a man of science; it secured him recognition as such in scientific circles at home and abroad, and was the immediate cause of his election, on June 12, 1766, into the Royal Society. The growing interest in the subject induced him to put together a _Familiar Introduction to the Study of Electricity_, which had also a considerable measure of success and was the means of popularising a knowledge of the main facts then known concerning Frictional Electricity. Priestley was instrumental in reviving the use of large electrical machines and batteries. The first of the large machines for which Nairne became famous was constructed in consequence of a request made to Priestley by the Grand Duke of Tuscany to procure for him the best machine that could be made in England. One of his machines, which figured in his _History_, and also in his _Familiar Introduction_, is in the possession of the Royal Society. CHAPTER V Goes to Leeds as minister of the Mill Hill Chapel—Resumes his studies in Speculative Theology—_The Theological Repository_—Becomes a Unitarian—Priestley as a controversialist—His Theory and Practice of Perspective—His literary characteristics—Begins his inquiries on Pneumatic Chemistry—His invention of soda-water—Receives the Copley Medal of the Royal Society.