LEOPOLD AVENBRUGGER, or AUENBRUGGER, a physician of Vienna, the discoverer of the important mode of investigating diseases of the chest and abdomen by auscultation. His method was to apply the ear to the chest, and to note the sounds it afforded on percussion by the hand, or what is called immediate auscultation. His Latin treatise, Inventum novum ex Percussione Thoracis Humani Interni Pectoris Morbos detegendi, published in 1761, excited little attention, until it was translated and illustrated by Corvisart, in 1808, when it soon led the way to Laennec's great improvement of aiding the ear by the stethoscope, or mediate auscultation. The great value of the method introduced by Avenbrugger, in the diagnosis of internal diseases, is now universally acknowledged. He was born at Gratz in 1722, and died in 1809.