Lung sounds.

In 1819, on the basis of observations with his newly invented stethoscope, Laennec published L'Auscultation Mediate.' In this masterly thesis he described and classified all the major lung sounds and suggested how they might correlate with lung abnormalities. Within three years the Scottish physician John Forbes translated Laennec's thesis into English' and by the end of the nineteenth century the subjective analysis of lung sounds was well established in that the stethoscope had become the hallmark of the physician.