Portrait of Dr. Dumouchel is a 1910 painting by Marcel Duchamp.

Raymond Dumouchel was a former schoolmate and a student in Radiology, an emerging field at the time (X-rays had been discovered in 1895).

Duchamp painted the left hand of Dumouchel surrounded by an aura, suggestive of both the rays he worked with and his healing powers.

[1][2][3] In a letter to the Arensbergs, Duchamp writes: "The portrait is very colourful (red and green) and has a note of humour which indicated my future direction to abandon mere retinal painting.

"[4] Duchamp included a facsimile of the painting in the Boîte-en-valise.