Produced by Bryan Ness, LN Yaddanapudi and the Online Distributed Proofreading Team at https://www.pgdp.net (This book was produced from scanned images of public domain material from the Google Print project.) [Transcriber's Note: A few typographical errors have been corrected. Details are given at the end of the text.] HEADS OF LECTURES ON A COURSE OF EXPERIMENTAL PHILOSOPHY, PARTICULARLY INCLUDING CHEMISTRY, DELIVERED AT THE NEW COLLEGE IN HACKNEY. _By JOSEPH PRIESTLEY, LL.D. F.R.S._ AC. IMP. PETROP. R. PARIS. HOLM. TAURIN. AUREL. MED. PARIS. HARLEM. CANTAB. AMERIC. ET PHILAD. SOC. QUI DOCET DISCIT.--WM. LILLY LONDON: PRINTED FOR J. JOHNSON, NO. 72, ST. PAUL'S CHURCH-YARD. 1794. THE PREFACE. Situated, as I happily am, in the neighbourhood of the _New College at Hackney_, an institution that does honour to the Dissenters, an institution open to all persons without distinction[1], and connected as I am by friendship with the tutors, I was glad to give it every assistance in my power; and therefore undertook to read the _Lectures on History and General Policy_ which I had composed when I was tutor at Warrington, and also to give another course on the subject of _Experimental Philosophy_. With this view I drew up the following _Heads of Lectures_; and, to save the students the trouble of transcribing them, they are now printed. To other persons they may serve as a compendious view of the most important discoveries relating to the subject. [Footnote 1: One gentleman of the Roman Catholic persuasion, and several of the Church of England, are now in the College.] As it was found most convenient, with respect to the other business of the college, to confine this course to one lecture in a week, I contrived to bring within that compass as much of the subject of experimental philosophy as I well could, and especially to include the whole of what is called _chemistry_, to which so much attention is now given, and which presents so many new fields of philosophical investigation. Besides that the plan of the young gentlemen's studies would not admit of it, I think it most advisable not to trouble beginners with more than a large outline of any branch of science. By this means they are not fatigued by too long an attention to any one subject, a greater variety of articles may be brought before them, and in future life they may pursue any of them as much farther as their inclination may dispose, and their ability and opportunity shall enable, them to do it. I do not give any account of the _experiments_ introduced into the several lectures. They will be sufficiently indicated by the subjects of them. They were as many as I could conveniently make within the time; and where the experiments themselves could not be made, I usually exhibited both the different substances employed in them, and those that were the result of them.