 Virchow discovered the clinical syndrome which he called ochronosis, a metabolic disorder in which a patient accumulates homogentisic acid in connective tissues and which can be identified by discolouration seen under the microscope.He found the unusual symptom in an autopsy of the corpse of a 67-year-old man on 8 May 1884.This was the first time this abnormal disease affecting cartilage and connective tissue was observed and characterised.