Robley Dunglison, M.D. / engraved by A.H. Ritchie ; from a daguerreotype by M.P. Simons.

Half-length portrait, facing front.

The daguerreotype method of the photographic process was invented by Louis Daguerre in the 1830s. It was the first photographic process and it was widely used in the mid-19th century. The process involves exposing a silver-coated copper plate to light in a camera, which then creates an inverted, highly detailed image on the plate. The plate is then treated with chemicals to make the image visible and fixed in place.