https://creativecommons.org/publicdomain/zero/1.0/https://www.rawpixel.com/image/13955164
Three researchers outside the British experimental hut set up near Ostia to verify the mosquito-malaria theory. Coloured photograph of a pen drawing by A. Terzi, ca. 1900.
Original public domain image from Wellcome Collection
Public DomainFree CC0 image for Personal and Business use