Isaac Newton, Natural Philosopher
The year is 1670. In the Philosophical Transactions, Newton has just published a series of trials involving the use of prisms and rays of light. One partciular trial, number 44, would be the subject of further debate. Dubbed the experimentum crucis, or crucial experiment, Newton claims to demonstrate the immutability of coloured rays of light. In other words, not only is white light made up of constituent 'coloured rays', but these rays can be refracted out with the use of a suitable prism. A second refraction of such a pure ray, Newton claims in Trial 44, introduces no further color diffraction. Put simply, a 'pure' ray will remain the same colour when refracted through a second prism.
You are to attempt this experiment and report back your findings and results to the Royal Society. Good luck. It is recommended that you have Internet Explorer 4.0 or 5.0, although this demonstration will also work in Netscape 3, 4 and 4.5 (albeit not as aesthetically pleasing). It is also necessary that you have JavaScript enabled in order for the demonstration to correctly run.