Letter from Newton to Henry Oldenburg, dated 5 December 1674
Cambridge Decemb 5th 1674.
Sir
I am sorry you put your self to the trouble of transcribing Francis Linus's conjecture, since (besides that it needs no answer) I have long since determined to concern my self no further about the promotion of Philosophy. And for the same reason I must desire to be excused from ingaging to exhibit yearly philosophic discourses, but yet cannot but acknowledge the honour done me by your Counsel to think of me for one amongst that list of illustrious persons who are willing to perform it, & therefore desire to have my thanks returned to them for the motion. If it were my lot to be in London for sometime, I might possibly take occasion to supply a vacant week or two with something by me, but that's not worth mentioning.
If you think fit you may to prevent Francis Linus's slurring himself in print with his wide conjecture, direct him to the scheme in my second answer to P. Pardies [1] & signify (but not from me) that the experiment as it is represented was tryed in clear days, & the Prism placed close to the hole in the window so that the light had no room to diverge, & the coloured image made not parallel (as in his conjecture) but transvers to the axis of the Prism.
Your humble Servant
I. Newton
[1] Philosophical Transactions N. 110. p. 219