touching his Theory of Light and Colours. 213 



is at its nearest distance 

 to N, so as to touch the 

 circle described about 

 N, with that distance ; 

 by the last of which vi- 

 brations, expanding or 

 contracting the medium 

 there, the ray is licensed 

 to recede again from N, 

 and go on to make the 

 colours; or further bent 

 about N, till the inter- 

 val of the next wave 

 overtake it, and give it 

 liberty to go from N, 

 very nearly in the line it 

 is then moving, suppose 

 toward Z, to cause the 



'biriw 



>T ■ 

 9flw f r {i3Up Jnar 

 .iM bimil nfchWi ,9in.8bjMn iaih hap 

 Jui biiuos \o %\ ityma otis otf ji siaqmoa 





iiisaisilinm js 



oiioBibi ? io bi i 



Indira i&zas 

 ►a Itaimim 

 \ 5£ ojjii "gm 



° 



\ ■"IttWUJ h: ; 



\ obH .'tU 

 \ iiJfi id 1 



i* bad 1 



ioH ai loritiiB ad) bit A 

 • moil )i b&t „.-- 



rlstfieoqqo £*fcr " 



3 ■" """ 



Oil 

 Offt 



Jnguorb 

 .•JOfflriiB 

 A 



,--- D WO<£ 



■ 



faint light spoken of | \ 



above. You will under- 

 stand me a little better, 

 by comparing this with 

 what was said of the co- 

 lours of thin transpa- 

 rent plates, comparing 

 the greatest distance 

 that the ray goes from 

 GBH towards N, to the 

 thickness of one of those 

 plates. Something too 

 there is in Descartes's 

 explication of the rain- 

 bow's colours, which 



would give further light in this. But I have no time left 

 to insist further upon particulars; nor do I propound this 

 without diffidence, having not made sufficient observation 

 about it. ><! A t .o^b9w i>ji> d O'/iM $ni 



rl 



Letter from Newton to Oldenburg, dated Jan. 25, 1675-76. 



Sir, -yierlj. 9"Of{£e#q z)\ 



I received both yours, and thank you for your care in dis- 

 posing those things between me and Mr. Sinus. I suppose 

 his friends cannot blame you at all for printing his first letter, 

 it being written, I believe, for that end, and they never com- 

 plaining of the printing of that, but of the not printing of that 



F 



" — o 



C 



