into rays of different colored light by means of a prism Newton invented the method for determining the coefficients of refraction of different bodies. This is done by making a ray pass through a prism, so that deviation is minimal. Let the angle of a prism be I and the deviation of the ray be &, the reflective index will be sin (I+&) cosec: 1/2I. Later Newton failed at completing a few parts of his experiments and abandoned his hopes of making a refracting telescope, which should be achromatic. Instead he designed a reflecting telescope and later the reflecting microscope.Newton wrote a paper on fluxions in October 1666. This was a work which was not published at the time but seen by many mathematicians and had a major influence on the direction the calculus was to take. Newton thought of a particle tracing out a curve with two moving lines, which were the coordinates. The horizontal velocity x' and the vertical velocity y' were the fluxions of x and y associated with the flux of time. The fluents or flowing quantities were x and y themselves. With this fluxion notation y'/x' was the tangent to f(x,y) = 0. In his 1666 paper Newton discusses the converse problem, given the relationship between x and y'/x' find y. For that reason the slope of the tangent was given for each x and when y'/x' = f(x) then Newton solves the problem by antidifferentiation. He also calculated areas by antidifferentiation and this work contains the first clear statement of the Fundamental Theorem of the Calculus. Newton had problems publishing his mathematical work. Barrow was in some way to blame for this since the publisher of Barrow's work had gone bankrupt and publishers were, after this, careful of publishing mathematical works. Newton's work on Analysis with infinite series was written in 1669 and circulated in manuscript. It wasn't published until 1711. Similarly his Method of fluxions and infinite series was written in 1671 and published in English ...
