More wildly rainbow-hued plates from “Les Phénomènes de la Physique” and “Le Monde Physique,” physics textbooks written by Amédée Guillemin and published in 1868 and 1882.

“Electrical light in rarefied gas”. 1868. French. Plate X, “Les Phénomènes de la Physique.” Aquatint by M. Rapine. Collections of the Wellcome Library. In the public domain due to age. via https://publicdomainreview.org/collection/optics-illustrations-from-the-physics-textbooks-of-amedee-guillemin-1868-1882
“”Polychromatic Fringes.” 1868. French. Plate VI, “Les Phénomènes de la Physique.” Mezzotint with watercolor by by René Henri Digeon, after an image by J. Silberman. Collections of the Wellcome Library. In the public domain due to age. via https://publicdomainreview.org/collection/optics-illustrations-from-the-physics-textbooks-of-amedee-guillemin-1868-1882
“Colored Rings.” 1868. French. Plate VIII,“Les Phénomènes de la Physique.” Mezzotint with watercolor byRené Henri Digeon, after an image by J. Silberman. Collections of the Wellcome Library. In the public domain due to age. via https://wellcomecollection.org/works/ms4gueju
.”Rainbow double refraction, reflection and scattering of light inside raindrops”, 1868. French. Plate XI,“Les Phénomènes de la Physique.” Lithograph with watercolor by René Henri Digeon, after an image by E. Ronjat. Collections of the Wellcome Library. In the public domain due to age. via https://wellcomecollection.org/works/d8zdj7jx