LONDON:
Printed for William Innys at the West-End of St. Paul's. Mdccxxx.
TITLE PAGE OF THE 1730 EDITION
Part of the ensuing Discourse about Light was written at the Desire ofsome Gentlemen of the Royal-Society, in the Year 1675, and then sentto their Secretary, and read at their Meetings, and the rest was addedabout twelve Years after to complete the Theory; except the third Book,and the last Proposition of the Second, which were since put togetherout of scatter'd Papers. To avoid being engaged in Disputes about theseMatters, I have hitherto delayed the printing, and should still havedelayed it, had not the Importunity of Friends prevailed upon me. If anyother Papers writ on this Subject are got out of my Hands they areimperfect, and were perhaps written before I had tried all theExperiments here set down, and fully satisfied my self about the Laws ofRefractions and Composition of Colours. I have here publish'd what Ithink proper to come abroad, wishing that it may not be translated intoanother Language without my Consent.
The Crowns of Colours, which sometimes appear about the Sun and Moon, Ihave endeavoured to give an Account of; but for want of sufficientObservations leave that Matter to be farther examined. The Subject ofthe Third Book I have also left imperfect, not having tried all theExperiments which I intended when I was about these Matters, norrepeated some of those which I did try, until I had satisfied my selfabout all their Circumstances. To communicate what I have tried, andleave the rest to others for farther Enquiry, is all my Design inpublishing these Papers.
In a Letter written to Mr. Leibnitz in the year 1679, and publishedby Dr. Wallis, I mention'd a Method by which I had found some generalTheorems about squaring Curvilinear Figures, or comparing them with theConic Sections, or other the simplest Figures with which they may becompared. And some Years ago I lent out a Manuscript containing suchTheorems, and having since met with some Things copied out of it, I haveon this Occasion made it publick, prefixing to it an Introduction, andsubjoining a Scholium concerning that Method. And I have joined withit another small Tract concerning the Curvilinear Figures of the SecondKind, which was also written many Years ago, and made known to someFriends, who have solicited the making it publick.
I. N.
April 1, 1704.
In this Second Edition of these Opticks I have omitted the MathematicalTracts publish'd at the End of the former Edition, as not belonging tothe Subject. And at the End of the Third Book I have added someQuestions. And to shew that I do not take Gravity for an essentialProperty of Bodies, I have added one Question concerning its Cause,chusing to propose it by way of a Question, because I am not yetsatisfied about it for want of Experiments.
I. N.
July 16, 1717.
This new Edition of Sir Isaac Newton's Opticks is carefully printedfrom the Third Edition, as it was corrected by the Author's own Hand,and left before his Death with the Bookseller. Since Sir Isaac'sLec