Images like these, which show glasses of different coloured urine, would have been used by medieval doctors to help diagnose illness. As well as colour, physicians would check the smell and even taste to determine whether a patient was unwell, according to the theory of the Four Humours. This approach to medical diagnosis, originally developed by ancient Greek physicians Hippocrates (d. c. 370 BC) and Galen (d. c. 210), stated that illness was caused when one of four bodily liquids (or humours), namely blood, phlegm, black bile and yellow bile, fell out of balance.
The diagrams appear in a miscellany, written in England in the first quarter of the 15th century. In addition to several medical treatises, the manuscript contains a variety of material, including astrological works; a discussion of the making and management of wine; a text on the planting, grafting, and culture of trees; and a collection of cookery recipes.