The manuscripts, letters, and other papers of Newton have been preserved in different collections. His correspondence with Cotes relative to the second edition of the Principia, and amounting to between sixty and a hundred letters, a considerable portion of the manuscript of that work, and two or three letters to Dr. Keill on the Leibnitzian controversy, are preserved in the library of Trinity College, Cambridge. Newton’s letters to Flamstead, about thirty-four in number, are deposited in the library of Corpus Christi College, Oxford.[136] Several letters of Newton, and, we believe, the original specimen which he drew up of the Principia, exist among the papers of Mr. William Jones (the father of Sir William Jones), which are preserved at Shirburn Castle, in the library of Lord Macclesfield. But the great mass of Newton’s papers came into the possession of the Portsmouth family through his niece, Lady Lymington, and have been safely preserved by that noble family. There is reason to believe that they contain nothing which could be peculiarly interesting to science; but as the correspondence of Newton with contemporary philosophers must throw considerable light on his personal history, we trust that it will ere long be given to the public. APPENDIX. No. I. OBSERVATIONS ON THE FAMILY OF SIR ISAAC NEWTON. In the year 1705, Sir Isaac gave into the Herald’s Office an elaborate pedigree, stating upon oath _that he had reason to believe_ that John Newton of Westby, in the county of Lincoln, was his great-grandfather’s father, and that this was the same John Newton who was buried in Basingthorpe church, on the 22d December, 1563. This John Newton had four sons, John, Thomas, Richard, and William Newton of Gunnerly, the last of whom was great-grandfather to Sir John Newton, Bart., of Hather. Sir Isaac considered himself as descended from the eldest of these, _he having, by tradition from his kindred ever since he can remember, reckoned himself next of kin (among the Newtons) to Sir John Newton’s family_. The pedigree, founded upon these and other considerations, was accompanied by a certificate from Sir John Newton, of Thorpe, Bart., who states that he had heard his father speak of Sir Isaac Newton _as of his relation and kinsman_, and that _he himself believed that Sir Isaac was descended from John Newton, son to John Newton of Westby, but knoweth not in what particular manner_. The pedigree of Sir Isaac, as entered at the Herald’s Office, does not seem to have been satisfactory either to himself or to his successors, as it could not be traced with certainty beyond his grandfather; and it will be seen from the following interesting correspondence, that upon making further researches, he had found some reason to believe that he was of Scotch extraction. _Extract of a Letter from the Reverend Dr. Reid of Glasgow to Dr. Gregory of Edinburgh, dated 14th March, 1784._