The real skeptical inquirer wonders . . .
How do we know that the blood on the Shroud is real? Canadian Society of Forensic Science Journal (1981)
Using ultraviolet-visible reflectance and fluorescence spectra, S. F. Pellicori analyzed the spectral properties of the Shroud's image color, the blood, and the non-image areas. These are quantitative measurements. They are based on reflectance and not a person's visual interpretation of indefinite splotches of different optical density. The spectra carry much important information, and they can not be ignored. This is documented in Applied Optics (1980). pp. 1913-1920]. These show the properties of the
Alan Adler, an expert on porphyrins, the types of colored compounds seen in blood, chlorophyll, and many other natural products concluded that the blood is real. In collaboration with John Heller, the conclusions that the blood is real was published in the peer-reviewed scientific journal Applied Optics (also 1980). The heme was converted into its parent porphyrin, and this was confirmed with spectral analysis.
Baima Bollone also found both the heme porphyrin ring of blood and the globulin in flakes of blood from Shroud samples, independently confirming the work of Adler and Heller.
In addition, the x-ray-fluorescence spectra showed excess iron in blood areas, as expected for blood. Microchemical tests for proteins were positive in blood areas but not in any other parts of the Shroud.
Qualitative chemical analyses are designed to detect the presence of specific substances. If they detect one, it is almost certainly present. Such tests are designed to have no or few false positive results. The tests can be repeated with fresh reagents by independent observers, and the results should agree. There are usually multiple tests for the same compounds or functional groups. Detection limits are generally known. If a material is not detected, it can probably safely be rejected. Analytical results can be used objectively to test many different hypotheses.
Chemical tests by E. J. Jumper, A. D. Adler, J. P. Jackson, S. F. Pellicori, J. H. Heller, and J. R. Druzik are documented in "A comprehensive examination of the various stains and images on the Shroud of Turin," ACS Advances in Chemistry, Archaeological Chemistry (1984)
Other material is provided by J. H. Heller and A. D. Adler in "A Chemical Investigation of the Shroud of Turin," Canadian Society of Forensic Science Journal and by L. A. Schwalbe and R. N. Rogers, Analytica
Chimica Acta (1982)
See: What else can be observed about the bloodstains?
