( 3®7S ) 
PHILOSOPHICAL 
TRANSACTIONS. 
February 19, 16^, 
The C ON TENTS. 
J Letter of Mr.Ifaac T^lcmoD^'Mathematick^Profeffbr in the Vniverfi^ 
ty of Cambridge • containing his Nen> Theory about Light and Co- 
lors : Where Light is declared to be not Similar or Homogeneal ^ but 
conjiflingoj difformrays^ fome of wbicb are more refrangible than 0- 
thers : And Colors are affirm d to be not Salifications of Light, de- ^ 
rivd from J{efr anions of natural Bodies^ {as 'tis generally believed • ) 
but Original and Connate f roper ties ^ which in divers rap are divers % 
Where Jeveral Obfervations and Experiments are alledged to prove the 
fatd Theory. An Accomptof fome Boo^ t I, A Defcriptionof the 
^ EASTINDIAN COASTS, MA LAB A J{, COIiOMANDEL, 
CETL0N,6c. in Dntcky by VhllBMxus, IL Aotonii ie Grand 
INSTITVTIO THILOS OP HI Mjitcmiium principia Renati ^ 
Des-Cartes5 novdmethodo adornata & explicata. Hi. An Effay 
to the Advancement of MVSICK^'-i by Thomas Salmon JlLJ,' 
Advertifement about Ihxon Smyroseus» An Index for the TraHs 
of the Tear 167 1. 
A Letter of Mr. Ifaac NewtODj Profejfor of the Mathematic\s in the 
Vniverjity of Cambridge ; containing his Nem Theory about Light and 
Colors : fent by the Author to the Publfher from Cambrid^e^ Febr. 6, 
1 6^ 5 in order to be commumcated to the R. Society^ 
S I R, 
TO perform my late promife to yoUj I ftiali without further 
ceremony acquaint you, that in the beginning of the Year 
1666 (at which time I applyed my lelf to the grinding of Optick 
glaffes of other figures than Spherical,^ I procured me a Triangu- 
lar glafs-Prifme^ to try therewith the celebrated Phcenomsna of 
G g g g ColoiiTS, 
