“Light propagates and spreads not only directly, through refraction, and reflection, but also by a fourth mode, diffraction.”
Lumen propagatur seu diffunditur non solum Directe, Refracte, ac Reflexe, sed etiam alio quodam quarto modo, Diffracte.
Physico-mathesis de lumine, coloribus, et iride, aliisque adnexis libri duo: opus posthumum, published in Bologna (1665), http://books.google.com/books?id=FzYVAAAAQAAJ&printsec=frontcover&source=gbs_summary_r&cad=0#PPP27,M1 Proposition I.