https://creativecommons.org/publicdomain/zero/1.0/https://www.rawpixel.com/image/13960664Edit ImageSaveSaveEditCropCustom TextOptics: spectra of various substances. Colour aquatint by R.H. Digeon, ca. 1868.Original public domain image from Wellcome CollectionMorePublic DomainFree CC0 image for Personal and Business useInfoView CC0 LicenseJPEGSmall JPEG 1200 x 799 px | 300 dpiLarge JPEG 3249 x 2164 px | 300 dpiFree DownloadOptics: spectra of various substances. Colour aquatint by R.H. Digeon, ca. 1868.More