lead

Evidence

"urine is often compared to everyday foodstuffs such as cabbage stalks, apples and milk and to everyday substances such as ink and lead."

Remarks

Lead is listed as an everyday substance utilized in the corpus of Middle English uroscopy texts to assist in the diagnosis of urine by comparison (p. 174). While used here as a descriptor, lead-based compounds were prominent in the medieval palette of pigments and scientific materials.