Ticks: O R, A TREATISE O F T H E Reflections, Refractions, Inflexions and Colours u, OF • i-r-* '"^^ L I G H T. The Fourth Edition, corrected. By Sir ISAAC NEWTON^ L O N D O N: Printed for William InnYs at the WeftEnd of St. Paul's. Mdccxxx Advertisement Lore* suing Dis:ourf? about Light • was written at the Desire of some Gentlemen of the Royal-Society,, in the Year 1675s, and then sent to their Secretary, and read at their Meetings, and1 the\ reft was added about twelve Years after to complete the Theory•.. except the third Book,, and the last Proposition of the Second, which were since put together out of scatter d Papers. , To .avoid being engaged in Disputes about A z these these Matters, I have hitherto delayed the printing, and should fill have delayed it, had not the Importunity of Friends prevailed upon me. If any other Papers mit on this Subjeff are got out 0/ wy Hands they are imperfect, and were perhaps written before I had tried all the Experiments here set down, and fully satisfied my self about the ha ws of Refractions and Composition of Colours. I have here publiful what I think proper to come abroad, wishing that it may not be translated into another Language without my consent. The Crowns of Colours, which sometimes appear about the Sun and Moon, I have endeavoured to give an Account of; but for want want of sufficient Observations leave that Matter to be further examined. The SubjeB of the Third Book I have also left imperfect, not having tried all the Experiments vohich I intended when I was about these Matters, nor repeated some of those which I did try, until I had satisfied my self about all their Circumstances. To communicate what I have tried, and leave the rest to others for farther Enquiry, is all my Design in publishing these Papers, |