In my life, I've twice been put into short promotional clips plugging my university. Every time, the guy doing the filming does exactly the same thing: he tells me to hold a flask or a test tube of colored water up and peer wisely at it. I don't think I've ever done such a thing in the lab, but what can you do? It's the conventional image of the scientist (I've also had to pose in two other stereotypical scenes: looking into a microscope, and standing at a chalkboard. At least I do do those things.)

So it was interesting to see a very brief note in this week's Nature on the origin of the archetypal image of the chemist.. It's a pose hallowed by over 700 years of history!

So where does the pose come from? As Joachim Schummer and Tami Spector pointed out at a recent conference in Paris on the public image of chemistry, the answer lies in the image in the top left. This appeared in a book dating from 1283, the Latin translation of Avicenna's Canon of Medicine, and shows not a chemist but a doctor. The flask contains not a solution synthesized by alchemy but a sample of a patient's urine—diagnoses were typically made by uroscopy, the practice of inspecting the urine for colour, clarity and other qualities.

When Paracelsus introduced chemistry into medicine (so-called iatrochemistry) in the early seventeenth century, this image of the gazed-at flask transferred itself from medicine to 'chymistry', and subsequently became so much a part of the subject's visual language that it is alive and well today.

At least none of the photographers expected me to wear that ugly brown dress in our sessions.

Dr William Kimler pointed me to a much nicer picture of the standard pose:

It really makes me want to go to work wearing my bathrobe and a cape. We have rather lost our sense of style in lab attire, haven't we?