Van Swieten's work consisted of commentaries upon the aphorisms of Boerhaave. The Vienna professor did not, however, limit himself to the consideration of the aphorisms alone, but made his work also a compendium of his own clinical experiences with acute and chronic diseases. As a matter of fact his commentaries on the aphorisms are each a monograph on some special disease. The two last volumes of this commentary appear after the publication of Auenbrugger's book on percussion, one volume being published in 1772, the other in 1774. The first of these articles contains a long article on pulmonary consumption, and the other an almost equally long chapter on pleurisy with effusion. In neither of the volumes, however, is there any mention of percussion, or of Auenbrugger's work, though if Van Swieten had given any serious attention to the subject, he must have become convinced how valuable Auenbrugger's invention was in the diagnosis of these conditions. This omission is all the more surprising as Auenbrugger was a pupil of Van Swieten's and practically dedicated his _Inventum Novum_ to his master. He mentions Van Swieten's work several times in his little book. Auenbrugger's {70} investigations were not unknown to Van Swieten then, and the only conclusion to be drawn from his neglect to mention Auenbrugger's methods is that he deliberately omitted reference to them because of his failure to recognize the value of the discovery. This constitutes one of the most serious blots on Van Swieten's medical career. He was succeeded as the head of the clinic in Vienna by De Haen, who also came from Leyden and brought with him the methods of Boerhaave's clinical school. As the time during which Auenbrugger was making his valuable observations at the Spanish military hospital coincides with the years when De Haen was professor of clinical medicine, and when he was frequently indebted to his colleague of the Spanish hospital for his cases for demonstration, it is impossible to conceive that Auenbrugger or his work should have remained unknown to the distinguished head of the clinic.