Working Bloody Miracles

Working Bloody Miracles, by Luigi Garlaschelli, Franco Ramaccini and Sergio Della Sala in the peer reviewed journal Nature in 1991, is a scientific investigation proposing a chemical explanation, based on a thixotropic mixture, for how a substance resembling dried blood could appear to liquefy on cue, directly relevant to reported liquefying-blood relics such as that of Saint Januarius in Naples. Its authority rests on peer review in one of the most rigorously reviewed general science journals and on the authors' own laboratory replication of the physical effect. Its limit is that a laboratory demonstration that a natural mechanism could produce the observed effect is not itself direct forensic proof of what any specific historical relic is actually made of, since the relic itself was not destructively tested, so the study establishes a plausible natural explanation rather than a settled chemical identification of the object in question.