16th century medicine. A guide to uroscopy, diagnosing a variety of medical conditions from the colour and clarity of the urine. The physician would use a special flask to collect the urine, then compare it with this chart in order to formulate a diagnosis. Although in many respects primitive and inaccurate, it was the only non-invasive form of diagnosis for many centuries. This woodcut comes from 'Epiphanie medicorum' by Ulrich pinder, published in Nuremberg in 1506.