53. Mercury’s In Retrograde

Although generally thought of as harmful today, mercury was used medicinally for over 3,000 years. It was a popular “cure” for syphilis in Europe from the 17th to the 19th centuries. Mercury was such a common treatment for syphilis, in fact, that most (if not all) of the men on the Lewis and Clark expedition received mercury dosing. 

Venereal disease was a rampant problem for the expedition, and mercury was prevalent as a result. The men took so much mercury that historians today can easily locate their campsites throughout the U.S. Wherever they camped resulted in high concentrations of mercury left behind by the men’s poop. Gross, but interesting.