Catalogue Entry: OTHE00101
 October 19, 1675. Macclesfield Correspondence, vol. ii. P. 280.
 "Harum . . . librationum causas Hypothesi elegantissima explicavit nobis vir cl. Isaac Newton, cujus humanitati hoc et aliis nominibus plurimum debere me lubens profiteor." — Mercator's Institutiones Astronomicæ; , p. 286.
 Newton's letter had been forwarded to Mr. Lucas, and therefore the sentence does not appear in it. — See Phil. Trans., No. 128, p. 703.
 Eddleston's Correspondence, App. No. xvi. p. 260.
 He wrote a work entitled, Herefordshire Orchards a Pattern for England, 1656. See Birch's Hist. of the Royal Society, vol. iv. p. 235.
 See Appendix, No. II.
 Dr. Whewell states that Descartes regarded light as "consisting of small particles emitted by the luminous body," but Mr. Vernon Harcourt (Letter to Lord Brougham, p. 32) has shewn the incorrectness of this opinion. See Œuvres de Descartes, tom. vii. pp. 193, 240.
 Newtoni Opera, tom. iv. pp. 325, 326.
 Phil. Trans., 1672, No. 88, p. 5088.
 Newtoni Opera, tom. iv. pp. 378-381; or Birch, vol. iii. p. 278.
 In a paper entitled "Observations," which accompanied this letter, but which was not printed, Newton says that Hooke, in his Micrographia, had "delivered many very excellent things concerning the colours of thin plates, and other natural bodies, which he had not scrupled to make use of as far as they were for his purpose."
 In his Optics, published many years after this, in 1704, Newton does not give Hooke the credit of having made these observations.
 Letter to Boyle, Newtoni Opera, tom. iv. pp. 385-395.
 Phil. Trans., 1801; or Lectures on Natural Philosophy, vol. ii. p. 614.
 Ibid., vol. i. p. 477.
 Optics, edit. 3d, 1720, pp. 336, 339.
 Fatio D'huillier, the particular friend of Newton.
 Huygenii Exercitationes Mathematicæ, &c., Fascic. i. p. 173.