In reviewing the theories and lives of those mentioned as medical luminaries of the eighteenth century, one experiences a feeling of mingled respect and disappointment--respect for the devoted way in which they worked and sought for the truth, and disappointment at so much waste of intellectual power and labor. The lesson is also taught, and should be impressed, that in all so-called new systems old principles for the most part reappear, and that the labors of the past are rarely so deliberately consulted as to guard against repetition and revamping of theories that had long before been proved futile. Let me now mention a few other of the physicians of the last century who have left more or less of an impress upon their successors and upon our science. One man, in particular, historians are wont to remember with the honor that was denied him by his colleagues and contemporaries. I refer to Leopold Avenbrugger, who was born in Graz in 1722, and who, after pursuing his philosophical and professional studies in his native city, obtained, at the age of twenty-nine, charge of a Spanish military hospital; while thus employed lie invented the art of percussion as applied to diagnosis. This he gave the test of experience during seven long years before making it known to the profession, and even then it was not appreciated, but remained practically unnoticed until after his death, which occurred in 1809. He did receive a patent of nobility from the Emperor Joseph II, but this hardly compensated him for the contumely heaped upon him by his colleagues. Paulus Ægineta employed sounds and specula; Santoro used the balance, counted the pulse, and resorted to the use of the thermometer; Boerhaave employed the thermometer and the simple lens; Floyer, and after him Haller, utilized the watch in marking seconds; a Salernian practitioner utilized auscultation and percussion in tympanites and ascites; but the{211} diagnosis of diseases of the great viscera by percussion was never known before Avenbrugger. His booklet of twenty-two pages, unsalable in his time, is to-day held worth far more than its weight in gold. His famous colleague, de Haën, wrote fifteen volumes without a word on percussion; Van Swieten did it no greater justice; in his great treatise the _History of Medicine_, Sprengel barely alludes to it; yet the contents of Avenbrugger's booklet were of more practical value than all that these other men ever wrote, or all the results of the vast and bloody campaigns during which it slept. In 1808 this volume was rescued from oblivion by Corvisart, who translated it into French and proclaimed its undying value.