Test Subject undergoing Electrostimulation, Guillaume Benjamin Amand Duchenne, 1876
Duchenne was a Paris neurologist who conducted research on genetic myopathies (muscle tissue diseases). In 1862 he published a book on this subject, of which the second expanded edition of 1876 is on view here. Duchenne used electric shocks to stimulate individual facial muscles. He subsequently took clinical photographs of the resulting (sometimes tortured) facial expressions. The book is an early example of how photographs helped to make new medical treatments more widely known.