This is the unassuming way in which Laennec announces his great discovery. He did not in modern fashion immediately cry "Eureka!" and announce the far-reaching importance of his method of diagnosis. For two years he devoted himself to the patient study of the application of his method and the appreciation of its possibilities and its limitations. Then he presented a simple memoir to the French Academy of Sciences on the subject. A committee of three, then distinguished members of the Academy, Doctors Portal, Pelletan and Percy were named to investigate the new discovery. It is rather interesting to notice, though almost needless to say, that the names of these men would be now absolutely unremembered in medical history but for the fortuitous circumstance that made them Laennec's investigators. Such is too often the ephemeralness of contemporary reputation. Fortunately for the committee, they reported favorably upon Laennec's discoveries. It is not always true of new and really great advances in medicine that they are received with proper appreciation upon their first announcement. Even Harvey said of his discovery of the circulation of the blood that he expected no one of any reputation in his own generation to accept it. It is not very surprising to find then in the matter of the Laennec investigators that there is a cautious reserve in their report, showing that they were not too ready {147} to commit themselves to a decided opinion on the importance of the new discovery, nor to any irretrievable commendation. The important part of the discovery was supposed to consist in the use of the wooden cylinder which Laennec came to employ instead of the roll of paper originally used. This wooden cylinder, now familiar to us under the excellent name invented for it by Laennec himself is the modern single stethoscope. This instrument is of great service. The really important part of Laennec's work, however, was not the invention of the stethoscope, but the exact observation of the changes of the breath sounds that could be noted with it in various forms of chest diseases. Laennec succeeded in pointing out how each one of the various diseases of the heart and lungs might be recognized from every other. Before his time, most of the diseases of the lungs, if accompanied with any tendency to fever particularly, were called lung fever. He showed the difference between bronchitis and pneumonia, pneumonia and pleurisy, and the various forms of tuberculosis and even the rarer pathological conditions of the lung, such as cancer, or the more familiar conditions usually not associated with fever, emphysema, and some of the forms of retraction.