https://creativecommons.org/publicdomain/zero/1.0/https://www.rawpixel.com/image/13990085![John Allen. Line engraving by G. van der Gucht.](https://images.rawpixel.com/image_social_portrait/cHJpdmF0ZS9zdGF0aWMvZmlsZXMvd2Vic2l0ZS8yMDI0LTAyL3djaHEzZmpjeXgtaW1hZ2UuanBn.jpg)
![John Allen. Line engraving by G. van der Gucht.](https://images.rawpixel.com/image_social_portrait/cHJpdmF0ZS9zdGF0aWMvZmlsZXMvd2Vic2l0ZS8yMDI0LTAyL3djaHEzZmpjeXgtaW1hZ2UuanBn.jpg)
John Allen. Line engraving by G. van der Gucht.
John Allen. Line engraving by G. van der Gucht.
Original public domain image from Wellcome Collection
Public DomainFree CC0 image for Personal and Business use