In 1512, Raphael painted an immense fresco over twenty feet wide known as La misa de Bolsena . The work, which is now in the Heliodorus Room in the Vatican, illustrates an alleged miraculous event that occurred in 1263.
Catholic tradition maintains that that year, during a mass officiated by the priest Pedro de Praga in the town of Bolsena, a small Italian town on the shores of Lake Homonymous, blood flowed from the host .
The fact seemed a signal addressed to the bohemian religious himself, since he, it seems, doubted the existence of the so-called transubstantiation . In essence, this doctrine maintains that the conversion of bread and wine into the body and blood of Christ occurs during consecration.
The miracle of Bolsena led Pope Urban IV to institute the Feast of Corpus Christi the following year , which celebrates the Eucharist and the physical presence of Jesus Christ in it. However, some researchers maintain that, if true, such a phenomenon could have a scientific explanation. In fact, it could have been the work of a microorganism.
In 1994, New Scientist magazine echoed a study promoted by researcher Johanna C. Cullen, from George Mason University, in Virginia, in which it argued that the inclusion in the Sacred Form of the bacterium Serratia marcescens would cause an effect similar . His essay, published by the American Society for Microbiology, maintained that, applied to a wafer, this pathogen causes the appearance of bloody red spots similar in appearance to vital fluid in a few days.
In 1998 and 2000, two other studies carried out by experts in organic chemistry and microbiology from the universities of Pavia, in Italy, and Tulane, in the USA, respectively, confirmed the results obtained by Cullen.
