Two vials of dried blood attributed to Saint Januarius (San Gennaro), the patron saint of Naples. The blood reportedly liquefies three times a year during special ceremonies.
History
The blood has been kept in Naples Cathedral since at least the 14th century. The liquefaction miracle has been documented since 1389. The blood liquefies on the saint's feast day (September 19), the Saturday before the first Sunday of May, and December 16.
Scientific Investigation
Spectroscopic analysis in 1902 confirmed the presence of hemoglobin. The liquefaction has been observed by scientists but not explained. Some skeptics propose thixotropy (a property of certain gels), but this has not been conclusively demonstrated. The Church has never allowed the vials to be opened for modern testing.
Spiritual Significance
The liquefaction is considered a miracle and a sign of the saint's continued intercession. When the blood fails to liquefy, it is traditionally seen as a bad omen for Naples.
