Auenbrugger's contribution to cardiology. History of percussion of the heart.

Percussion of the abdomen as a means of distinguishing between tympanites and ascites dates back into antiquity, but percussion of the thorax starts with Auenbrugger (Fig. I) whose Inventum Novum ex Percussione Thoracis Humani (Fig. 2) was published in I76i, the same year as Morgagni's great work on pathological anatomy. Auenbrugger's discovery of percussion was not entirely fortuitous for his father was an innkeeper, and he must have watched men tapping the wine barrels to find out how full or empty they were. He was also a good musician and wrote the libretto of an opera for which he was ennobled by the Empress in I784, SO that evidently he had a good ear for sound. Born at Gratz in I722, he studied medicine in Vienna under Van Swieten, graduating in 1752, and later became physician to the Spanish Hospital in Vienna where for seven years 'amid laborious and tedious exertions' he tested his method of percussion by dissections whenever possible and experimented on cadavers by filling the chest with water. Auenbrugger practised direct or immediate percussion, striking the patient's chest, covered by a shirt, with the finger tips of his gloved hand, first during normal breathing and then in full inspiration. He described the natural percussion sound in different parts of the chest, noting that over the space occupied by the heart the sound loses part of its natural clearness and becomes dull. His observations related mainly to lung disease, but two sections dealt with heart disease, namely section XLVI on dropsy of the pericardium and section XLVIII on aneurysm of the heart. He divided dropsy of the pericardium into serous and purulent varieties, noting a completely deadened percussion sound such as obtained by striking a fleshy limb. He also described the symptoms such as fainting, unequal pulse, swelling of the neck, and a tendency to fall asleep while sitting with the