"Reflexion, refraction, the formation of images by lenses. the mode of operation of the eye, the spectral composition and recomposition of the different kinds of light the invention of the reflecting telescope, the first foundations of colour theory, the elementary theory of the rainbow pass us by in procession, and finally come his of the colours of thin films as the origin of the next great theoretical advance, which had to await, over a hundred years, the coming of Thomas Young."