René Laënnec (1781-1826), a French physician, invented the stethoscope in 1816. Doctors use this instrument to listen to the sounds of the heart and other organs. Laënnec investigated diseases of the heart and the lungs, and published his conclusions in
A Treatise on Mediate Auscultation (1819). He died from tuberculosis, a disease on which he had become an expert. Laënnec was born in Quimper, France, and studied with Jean Nicolas Corvisart, Napoleon's favorite physician.