n Optics, Newton explained by white light that is reflected into a prism reflects the seperated colours of that light. He also described how depending on the certain angle that the prism positioned at in relation to the light, it would change the resulting spectrum of light. Newtons rings, which are a manifestation of the wave nature of light, was observed also in his time studying prisms at Cambridge.

Also discussed in Optics, Newton explained his thoughts on the chemical elements, and how each element possessed a different arrangement of atoms. He also attempted to explain chemical reactions due to "affinities".

He also described how telescopes that using refracting lenses could never overcome the distortions of chromatic dispersion (Schuster). He was able to construct the first relecting telescope which combated this problem.

His scientific method that was throughly explained in his first book was put to good use in Optics, which also propelled the worldwide acceptance of his corpuscular theory, which was noted in the book.