Urine analysis chart, 16th-century illustration. At centre, a medieval doctor is shown using a matula, a transparent bulbous flask that is held up to the light to examine the colour of urine samples. Different colours and associated conditions are described in the circular key. This page is from the work 'Epiphanic medicorum' (Nuremberg, 1506) by German physician Ulrich Pinder. For an alternative depiction of the chart, see image C047/8600.