This is the title page of what would be a five-volume edition of all works of Isaac Newton (1642-1727) known at that time. Note that this five-volume work (1779-1785), edited by Samuel Horsley (1733-1806), is much shorter than the more recent eight-volume collection, The Mathematical Papers of Isaac Newton (1967-1981), edited by Derek Thomas Whiteside (1932-2008).
This is the beginning of Newton's first letter to Gottfried Wilhelm Leibniz (1646-1716), the "Epistola prior," sent through Henry Oldenburg (ca. 1618-1677) on June 13, 1676. This letter (from vol. 1, p. 285) contains some of Newton's work on the calculus, including his first statement of the binomial theorem.
This page (vol. 2, p. 359) is from Newton's Principia Mathematica. It is the discussion of Proposition 29, Problem 6 from Book 2, Section 6 of that work.
This page, from vol. 3, p. 420, illustrates refraction of light through triangular prisms.
This diagram, Table IV from volume 4, shows how refraction of light is the cause of the rainbow.
Volume 5, containing papers on history and theology, was published in 1785. It is available via GoogleBooks.
Index to Mathematical Treasures