given the chair of geology. The discovery of vanadium In 1801, while examining mineral samples sent to him by the Purísima del Cardenal mine in Zimapán in the State of Hidalgo, del Río arrived at the conclusion that he had found a new metallic element. He prepared various compounds of the element, and observing their diverse colors, he named the element panchromium (Greek: παγχρώμιο "all colors"). Later, on observing that the compounds changed color to red on heating, he substituted the name erythronium (Greek: ερυθρός "red"). The following year he gave samples containing the new element to Alexander von Humboldt, who sent them on to Hippolyte Victor Collet-Descotils in París for his analysis. Collet-Descotils's analysis found (mistakenly) that the samples contained only chromium. Humboldt, in turn, rejected del Río's claim of the discovery of a new element, and del Río himself concluded his discovery had been an error. In 1830, 27 years after its initial discovery, Professor Nils Gabriel Sefström of Sweden rediscovered the element in a sample of iron of Taberg. He gave it its current name, vanadium, in honor of the Scandinavian goddess of love and beauty, Vanadis. In the same year, Friedrich Wöhler, the German chemist who had synthesized urea, analyzed some of del Río's samples of brown lead ore of Zimapán and demonstrated that Sefström's vanadium and del Rio's erythronium were the same. In 1831 the U.S. geologist George William Featherstonhaugh proposed without success that the element should be named rionium, in honor of its original discoverer. An extensive analysis of the publication history of papers relating to the discovery of the element suggests that the intervention of J. J. Berzelius on behalf of his students Sefström and Wöhler, was highly instrumental in influencing the element's attribution and naming, reflecting patterns of scientific prestige and control of discourse in the first half of the nineteenth century. In 1867 the English chemist Henry Enfield Roscoe isolated the pure metal for the first time. He used hydrogen to get rid of the chloride around the pure vanadium. Later life In 1805 del Río established an ironworks at Coalcomán. After overcoming numerous obstacles, he produced the first iron in Mexico, on 29 April 1807. Four years later, during the Mexican War of Independence, the royalists destroyed the ironworks. The iron he produced was superior to the celebrated imported iron from Biscay (Vizcaya), Spain. Del Rio was bitter about Humboldt's