Great Blue Skimmer dragonfly in nature. Original public domain image from Flickr https://www.rawpixel.com/image/4036769/photo-image-blue-green-purpleFree Image from public domain licenseCharles Michel, Abbé de l'Epée. Stipple engraving by F. Bonneville. https://www.rawpixel.com/image/13979964/charles-michel-abbe-lepee-stipple-engraving-bonnevilleFree Image from public domain licenseNicolas Léméry. Line engraving by N. Pitau after L.E. Ferdinand. https://www.rawpixel.com/image/13981479/nicolas-lemery-line-engraving-pitau-after-le-ferdinandFree Image from public domain licenseUnidentified young woman, in vignette-style by Thomas George Hemery https://www.rawpixel.com/image/14307450/unidentified-young-woman-vignette-style-thomas-george-hemeryFree Image from public domain licenseStephen Hales; with a vignette of his experiments on plant physiology. Line engraving by J. Hopwood, 1807, after T. Hudson. https://www.rawpixel.com/image/14008934/image-face-plant-personFree Image from public domain licenseFree blueberry mousse with fresh blueberries image, public domain dessert CC0 photo. https://www.rawpixel.com/image/5917063/image-background-public-domain-plantFree Image from public domain licenseEdmund L. Lushington, M.A., Professor of Greek by Thomas Annan https://www.rawpixel.com/image/14316747/edmund-lushington-ma-professor-greek-thomas-annanFree Image from public domain licenseRudolf Ludwig Karl Virchow. Photograph by J. C. Schaarwächter, 1891. https://www.rawpixel.com/image/13972140/rudolf-ludwig-karl-virchow-photograph-schaarwachter-1891Free Image from public domain licenseGenre scene: young French peasant girl by Jules Hautecoeur https://www.rawpixel.com/image/14289832/genre-scene-young-french-peasant-girl-jules-hautecoeurFree Image from public domain licenseJohn Ring. Stipple engraving by J. Rogers, 1824, after S. Drummond. https://www.rawpixel.com/image/14013597/john-ring-stipple-engraving-rogers-1824-after-drummondFree Image from public domain licenseGoing to work. The manager said, We have 150 workers beside the kids, September 1911. Photographer: Hine, Lewis. Original… https://www.rawpixel.com/image/8803132/photo-image-plant-person-grassFree Image from public domain licenseWilliam Hyde Wollaston. Stipple engraving by W. Holl [] after J. Jackson. https://www.rawpixel.com/image/13976967/william-hyde-wollaston-stipple-engraving-holl-after-jacksonFree Image from public domain licenseMargaret Bryan. Stipple engraving by J. Heath, 1801, after T. Kearsley. https://www.rawpixel.com/image/13995893/margaret-bryan-stipple-engraving-heath-1801-after-kearsleyFree Image from public domain licenseFree brown dog standing on grass field image, public domain animal CC0 photo. https://www.rawpixel.com/image/5911558/image-background-public-domain-dogFree Image from public domain licenseFree close up brown chihuahua dog's head image, public domain animal CC0 photo. https://www.rawpixel.com/image/5926267/photo-image-background-public-domain-dogFree Image from public domain licenseFree bouquet in glass vase on dining table image, public domain flower CC0 photo. https://www.rawpixel.com/image/5923503/photo-image-background-flower-public-domainFree Image from public domain licenseRoker, kijkend in een kruik (1670 - 1750) by anonymous and Cornelis Dusart https://www.rawpixel.com/image/13731604/roker-kijkend-een-kruik-1670-1750-anonymous-and-cornelis-dusartFree Image from public domain licenseThomas Jefferson. Stipple engraving, 1802, after G. Stuart. https://www.rawpixel.com/image/13971841/thomas-jefferson-stipple-engraving-1802-after-stuartFree Image from public domain licenseVirginia Julian Dalrymple (Lady Mrs. Francis Henry Champneys) by Oscar Gustave Rejlander https://www.rawpixel.com/image/14282732/image-face-person-artFree Image from public domain licenseJoseph Priestley. Line engraving by T. Holloway, 1795, after W. Artaud. https://www.rawpixel.com/image/13992990/joseph-priestley-line-engraving-holloway-1795-after-artaudFree Image from public domain licenseJohn Flamsteed. Line engraving by A. Birrell, 1795, after T. Gibson, 1712. https://www.rawpixel.com/image/14017010/john-flamsteed-line-engraving-birrell-1795-after-gibson-1712Free Image from public domain licenseGuillaume Rondelet [Rondeletius]. Stipple engraving by A. Tardieu. https://www.rawpixel.com/image/14021153/guillaume-rondelet-rondeletius-stipple-engraving-tardieuFree Image from public domain licenseFree labrador retriever dogs in wooden cage image, public domain animal CC0 photo. https://www.rawpixel.com/image/5908818/image-background-public-domain-dogsFree Image from public domain license"Man in Eastern Costume" by Jacques des Rousseaux by Johannes Baer https://www.rawpixel.com/image/14314523/man-eastern-costume-jacques-des-rousseaux-johannes-baerFree Image from public domain licenseCopy of a painting of three young women by Williams and Everett https://www.rawpixel.com/image/14308523/copy-painting-three-young-women-williams-and-everettFree Image from public domain licenseAristotle. Line engraving by A. Blanchard after P. P. Rubens. https://www.rawpixel.com/image/14003566/aristotle-line-engraving-blanchard-after-rubensFree Image from public domain licenseClose up golden retriever dog face. Original public domain image from Flickr https://www.rawpixel.com/image/3261326/free-photo-image-puppy-golden-retriever-animalFree Image from public domain license