https://creativecommons.org/publicdomain/zero/1.0/https://www.rawpixel.com/image/13953189Edit ImageSaveSaveEditCropCustom TextSix kinds of electric light produced in tubes containing different gases. Colour aquatint by M. Rapine, 1868.Original public domain image from Wellcome CollectionMorePublic DomainFree CC0 image for Personal and Business useInfoView CC0 LicenseJPEGSmall JPEG 1200 x 952 px | 300 dpiLarge JPEG 3081 x 2444 px | 300 dpiFree DownloadSix kinds of electric light produced in tubes containing different gases. Colour aquatint by M. Rapine, 1868.More