The initial chapters of Jefferson's Library were classified under the category of History. These ranged from Ancient History to contemporary American History. It was clear from Jefferson's viewpoint that the section would then logically address the history of the earth as well. Chapters 6-14 cover Natural History, including the hard and the applied sciences such as Natural Philosophy, Chemistry, Anatomy, Zoology, Botany, and Mineralogy. (Interestingly, astronomy and physics are treated as Philosophy in Jefferson's organizational scheme.) It is here that Jefferson's role as one of the leading intellectual and scientific lights of North America becomes evident. Vast sections of his science holdings are gifts from authors, anxious to hear Mr. Jefferson's reactions. In several instances, Jefferson strikes up an engaging and productive correspondence with scientists and inventors. He corresponded with Joseph Priestly regarding Phlogiston, and with others concerning Antoine Lavoisier's discoveries.