Within an 18-month period, 1665 to 1667, he made discoveries about light, color & gravitation
.... Then, in 1665, the plague 
closed the university, and for most of the following two years he was forced to... [DOC] [TLE] Free Flashcards about INVENTORS-J - StudyStack [PAR] WITHIN AN 18-MONTH PERIOD, 1665-1667, HE MADE DISCOVERIES ABOUT 
LIGHT, COLOR, AND GRAVITATION, NEWTON.