[Johann Lucas Schönlein (1793-1864), a researcher and clinician].

From 1833 to 1840, Johann Lucas Schönlein, a native of Bamberg, Germany, was Professor of Internal Medicine at the newly created University of Zurich, Switzerland. His career and professional personality are described succintly in this paper. Schönlein was a most successful clinical teacher. He was the first German professor to teach at Würzburg, 1819-1832) clinical percussion and auscultation. On the other hand, he obviously hated writing and publishing. His 3 important discoveries, all made during his years in Zurich, were published on a total of 3 printed pages: so-called typhoid crystals in patients' stools (1836), "peliosis rheumatica" (1837), and - most important - the causative agent of favus (1839), a fungus later named Achorion schoenleinii. This was the first instance of a human disease that could be clearly attributed to the action of a micro-organism.