Miracle attributed to the blood of the bishop of Benevento and patron saint of Naples, believed to have been martyred in 305 C.E. januarius’s exact identity is unknown; in fact, there is no evidence that he was an historical person. His fame rests solely on a relic: a vial of what is alleged to be his dried blood that is kept in Naples Cathedral and frequently shown to the public when, after varying intervals of time, it is observed to liquefy. There is no historical record of the “blood” prior to 1389, over one thousand years after the presumed date of januarius’s death. There are some twenty other saints’ bloods, with similar properties, to be found in and around the Naples area, which probably indicates the existence of a local artificial blood manufacturing technique in the 14th century. This was a period when the mass manufacture of relics was prevalent throughout Italy. It was not until the Council of Trent (1545-63) that reforms were brought about and rules laid down to clean up the trade and ensure the authenticity of relics.
No detailed scientific examination of the “blood” has ever been allowed, and descriptions of what happens vary. Some say beeswax has been mixed with the dried blood; others believe that the mixture is of olive oil and beeswax, with some red pigment such as dragon’s blood added. Whichever is the case, it is thought that it is the beeswax that melts when the vial is brought out into the heat. But at the same time as the contents of the vial turn to liquid, an increase in weight and volume has been noticed; this would not happen to a blend of beeswax and blood or olive oil. Taking this increase in weight and volume into account, it is more likely to be caused by deliquescence. There are many substances which deliquesce that is, have the property of picking up moisture from the air to such an extent as to dissolve in it; in other words, they become liquid when exposed to humid air (air high in water vapor). Scientists do not know what substance is in the vial, but whatever it is it cannot be blood, as blood is not deliquescent. When blood is released from the body it oxidizes, turns brown, and is attacked by fungi, going moldy.