Archaeologists Use Lewis & Clark's Laxatives to Find Lost Campsites

The Lewis and Clark expedition's 600 giant laxative pills, nicknamed "thunder-clappers," contained mercury, a stable compound. Traces of these pills are helping archaeologists pinpoint the expedition's campsites. High mercury levels in soil indicate old latrine pits, and military manuals help reconstruct the camp layouts. This discovery highlights the limitations of early 19th-century medical practices, where "heroic medicine", while sometimes effective, often did more harm than good.