
Image 1
Monaural stethoscope made of wood and ivory. Pierre Adolphe Piorry (1794-1879), a French physician, devised this form in 1829. Gift of The Medical and Chirurgical Faculty of the State of Maryland, National Museum of American History, online at https://americanhistory.si.edu/.

Image 2
William Baxter Closson, Oliver Wendell Holmes Sr. Transfer from the National Museum of American History, Division of Graphic Arts, Smithsonian Institution, 1971.169.