Founded by Thomas Dent Mutter in 1858 for medical research, the museum's contents include medical oddities, anatomical and pathological specimens, and antique medical equipment. Anatomical specimens include the conjoined liver of Siamese twins Chang and Eng Bunker; and a section of the brain of Charles J. Guiteau, who assassinated President Garfield. Medical instruments include a wooden stethoscope and Marie Curie's quartz-piezo electrometer