The Pee-in-a-Cup Test, circa 1500

Before X-rays and MRIs could peer inside the human body, physicians turned to bodily wastes, particularly urine, in order to make diagnoses. The practice of uroscopy arose from the observation that the color, consistency, smell, and even taste of urine change with different ailments. With a sample of the ailing person’s urine, physicians and laymen alike turned to widely popular illustrations known as urine wheels to make their diagnoses. While some associations were clearly flawed—such as the idea that turbidity could indicate that a woman was not a virgin—in many ways uroscopy paved the way for modern laboratory medicine.