Corvisart's most notable characteristic was a sympathetic encouragement of the work of others, especially in what concerned actual bedside observation. Laennec was at once put in most favorable circumstances, then, for his favorite occupation of studying the actualities of disease on the living patient and at the autopsy. For nearly ten years he devoted himself almost exclusively to the care and study of hospital patients. In 1812 he was made physician to the Beaujon Hospital, Paris. Four years later he was transferred to the Necker Hospital, where he was destined to bring his great researches to a successful issue. To the Necker Hospital, before long, students from all over the world flocked to his clinical lectures, to keep themselves in touch with the great discoveries the youthful master was making. In spite of rather delicate health Laennec fulfilled his duties of physician and professor with scrupulous exactitude and with a self-sacrificing devotion that was, unfortunately, to prove detrimental to his health before very long. One of his contemporaries says of him: "Laennec was almost an ideal teacher. He talked very easily and his lesson was always arranged with logical method, clearness and simplicity. He disdained utterly {144} all the artifices of oratory. He knew, however, how to give his lectures a charm of their own. It was as if he were holding a conversation with those who heard him and they were interested every moment of the time that he talked, so full were his lectures of practical instruction." Another of his contemporaries says, naïvely: "At the end of the lesson we did not applaud, because it was not the custom. Very few, however, who heard him once, failed to promise themselves the pleasure of assisting at others of his lectures." The work on which Laennec's fame depended and the discovery with which his name, in the words of our great American diagnostician, Austin Flint, the elder, will live to the end of time was concerned with the practice of auscultation. This is the method of listening to the sounds produced in the chest when air is inspired and expired in health and disease, and also to the sound produced by the heart and its valves in health and disease. Nearly two centuries ago, in 1705, an old medical writer quoted by Walshe, in his "Treatise on the Disease of the Lungs and Heart" said very quaintly but very shrewdly: "Who knows but that one may discover the works performed in the several offices and shops of a man's body by the sounds they make and thereby discover what instrument or engine is out of order!"