From 1670 to 1672, Newton lectured on optics.  During this period he investigated the refraction of light, demonstrating that the multicoloured spectrum produced by a prism could be recomposed into white light by a lens and a second prism.  Modern scholarship has revealed that Newton's analysis and resynthesis of white light owes a debt to corpuscular alchemy. 
In six pages this research paper examines these scientists in terms of the biographies Isaac Newton The Last Sorcerer by Michael ...
"Sir Isaac Newton" Microsoft® Encarta®. Copyright © 1998 Microsoft Corporation.
In the above passage Locke allows for two distinct types of experience. Outer experience, or sensation, provides us with ideas from the traditional five senses. Sight gives us ideas of colors, hearing gives us ideas of sounds, and so on. Thus, my idea of a particular shade of green is a product of seeing a fern. And my idea of a particular tone is the product of my being in the vicinity of a piano while it was being played. Inner experience, or reflection, is slightly more complicated. Locke thinks that the human mind is incredibly active; it is constantly performing what he calls operations. For example, I often remember past birthday parties, imagine that I was on vacation, desire a slice of pizza, or doubt that England will win the World Cup. Locke believes that we are able to notice or experience our mind performing these actions and when we do we receive ideas of reflection. These are ideas such as memory, imagination, desire, doubt, judgment, and choice.