up the vial and tilts it again to demonstrate that liquefaction has taken place. The announcement of the liquifaction is greeted with at the 13th-century Castel Nuovo. The ampoules remain exposed on the altar for eight days, while the priests move or turn them periodically to show that the contents remain liquid. Sir Francis Ronalds gives a detailed description of the May 1819 ritual in his travel journal. The liquifaction sometimes takes place almost immediately, but can take hours or even days. Records kept at the Duomo tell that on rare occasions the contents fail to liquify, are found already liquified when the ampoules are taken from the safe, or liquify outside the usual dates. Scientific studies While the Catholic Church has always supported the celebrations, it has never formulated an official statement on the phenomenon and maintains a neutral stance about scientific investigations. It does not permit the vials to be opened, for fear that doing so may cause irreparable damage. This makes close analysis impossible. Nevertheless, a spectroscopic analysis performed in 1902 by Gennaro Sperindeo claimed that the spectrum was consistent with hemoglobin. A later analysis, with similar conclusions, was carried out by a team in 1989. However, the reliability of these observations has been questioned. While clotted blood can be liquefied by mechanical stirring, the resulting suspension cannot solidify again. Measurements made in 1900 and 1904 claimed that the ampoules' weight increased by up to 28 grams during liquefaction. However, later measurements with a precision balance, performed over five years, failed to detect any variation. Various suggestions for the content's composition have been advanced, such as a material that is photosensitive, hygroscopic, or has a low melting point.Henri Broch. Le Paranormal (1985); ed. ext., Paris, Seuil, 1989, p. 109 However, these explanations run into technical difficulties, such as the variability of the phenomenon and its lack of correlation to ambient temperature. A recent hypothesis by Garlaschelli & al. is that the vial contains a thixotropic gel,; In such a substance viscosity increases if left unstirred and decreases if stirred or moved. Researchers have proposed specifically a suspension of hydrated iron oxide, FeO(OH), which reproduces the color and behavior of the 'blood' in the ampoule. The suspension can be prepared from simple chemicals that would have been easily available locally since antiquity. In 2010, Giuseppe Geraci, a professor in the Department of Molecular Biology at Naples's Frederick II