Overview

In 1816 French physician René Laënnec began using a device of his own invention to listen to the sounds of the living heart and lungs. This simple advance revolutionized the diagnosis of chest diseases and later contributed to understanding their pathology and therapeutics—that is, what they are and how to treat them.

Background

Some of the best observers in the history of medicine lived in the early nineteenth century. The state of medical science then was such that physicians could cure almost nothing but could recognize and describe a great deal that would escape physicians today. Using only their five senses, their skill in observation and description was generally more acute than that of...