JOHANNES DE KETHAM
FASCICULUS MEDICINAE, 1513
A senior doctor with his index finger raised is teaching his students about uroscopy (medieval urinalysis).
He is pointing to an oversized uroscopy flask delivered by a messenger wearing travelling clothes. He is explaining how an illness can be detected from the urine.
Uroscopy was an ideal method at the time for remote diagnosis. A messenger delivers the urine in a receptacle, which means the ill person does not have to embark upon a journey himself. A second messenger, in the form of a child, waits attentively for a diagnosis. There is a zealous student in the background.