Uroscopy is the now obsolete practice of using the smell, taste, and color of urine to diagnose illness. There were even charts to help doctors and other healers identify different types of urine.
Many diseases affect metabolism and many changes in metabolism can be detected in the urine. For example, diabetics will excrete sugar in their urine — sometimes enough sugar that it can be fermented into whisky. There are many other diseases that change the smell of a person’s urine, including the very descriptively named Maple Syrup Urine Disease or Sweaty Feet Syndrome, now much more likely to be diagnosed by electronic sensor arrays than actually tasting the urine.
(via edible geography)