Could the humidity from having a large bevy of visitors breathing in the same room have something to do with it, as well?
Whatever the physical cause, this is just plain creepy.
What is the composition of the "blood", anyway?
There’s no proof it’s his blood. There’s no proof that it is blood.....as far as I could see. The video is helpful...
Blood of San Gennaro Liquefies -- VIDEO (2014)
Catholic Word of the Day: BLOOD OF ST. JANUARIUS, 05-14-12
San Gennaro miracle recurs (St. Januarius's blood liquefies) (Catholic Caucus)[2011]
Naples: The Miracle of St. Januarius Happens on Time this Year. 2010
San Gennaro Miracle Recurs (Catholic/Orthodox Caucus)
Naples hails annual miracle of liquefying blood (San Gennaro) [St. Januarius] [2007]
San Gennaro (St. Januarius): New Miracle [2006]
Miracle of San Gennaro Repeated (St. Januarius) [2005]
Sept. 19: St. Januarius, Bishop & Martyr, and His Companions, Martyrs (Gueranger)
The Life Of St. Januarius
Saint's Dried Blood Liquefies in 'Miracle' [2002]
Saint's Blood Liquefies - Good Omen for the World [2001]