31 6 Sir I s a a c Newton’s Book III,

Spe®

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BOOK III.

Chap I.

Concerning the caufe of COLOURS inhe-rent in the LIGHT.

FTER this view which has been takenof Sir I s a a c Newto n’s mathema-tical principles of philofophy, and theufe he has made of them, in explain-ing the fyftem of the world, &c. thecourfe of my defign directs us to turnour eyes to that other philofophicalwork, his treatife of Optics, in which w T e fhall find our greatauthor’s inimitable genius difcovering it felf no lefs, than in

the