The court appointed Dr. Paul Coremans, Director of the Central Laboratory of the Belgian Museum, to lead the scientific team that was to test van Meegeren’s claims. The team conducted extensive tests on the paintings.
Coremans undertook chemical analysis of the pigments, which revealed that they contained a synthetic resin not discovered until 1900, supporting van Meegeren’s description of how he had accelerated the hardening of the paints. In contrast, two other chemists then showed that the microchemical tests done by Coremans gave exactly the same reaction when applied to aged historic binding agents, concluding that Coremans’ microchemical tests did not in fact provide evidence of the presence of synthetic resins.
Coremans used a series of microphotographs, taken with the aid of a stereo microscope, to show that there were inconsistencies between van Meegeren’s brush strokes and those of Vermeer. Later microphotography done by other experts lead to declarations that Coremans’ conclusions were misleading and erroneous.
The Coremans team then made a test painting following the exact procedure that van Meegeren claimed to have developed. The result was a painting had the exact same visual, physical, and chemical properties of the 14 paintings in question.
In addition, the Coremans team found that x-radiography showed there were remnants of an earlier painting underneath the paintings under study. Thus the crackle pattern of the underlayer did not match the crackle pattern of the upper paint surface. And, they found that although van Meegeren had carefully chosen ultramarine blue as did Vermeer, and avoided using more inexpensive blues developed after Vermeer’s time, van Meegeren’s pigment, unlike Vermeer’s, was slightly adulterated with cobalt blue during its manufacture.
The court decided that the preponderance of evidence supported van Meegeren’s claim, and the charges of collaboration with the enemy were dropped. In 1947, he was instead convicted of the much more minor charge of fraud for forging artists’ signatures, and received a relatively light sentence of one year in prison. He died before the sentence could be carried out.
However, the controversy raged on for many years after the trial. Many art historians refused to believe that all of the 14 paintings were forgeries. The scientific rebuttal of the conclusions of the Coremans team continued. A lawsuit was filed against Coremans by the owner of one of the questioned paintings, charging Coremans with giving “his expert opinion that a genuine Vermeer was an imitation by the hand of the painter van Meegeren” and thus greatly diminishing the painting’s monetary value. Coremans countersued for “alleged derogation of his expert qualifications.”
Many experts felt that an end to the controversy finally occurred in 1968, more than twenty years after the trial, when a new dating technique, lead-210, was developed. Minute levels of radioactivity were shown to be present in lead white pigments after they are produced from lead ores, due to the isotope lead-210. But lead-210 has a half-life of only 22 years, and thus the measurable radioactivity begins to decay immediately; by 200 years it is no longer detectable. Analysis of the questioned paintings showed that the lead white was of recent manufacture, and could not have dated back to the seventeenth century.
Re-examine all of the scientific evidence for this case. Prepare a group discussion paper indicating whether or not you agree that the preponderance of evidence conclusively demonstrates that the questioned paintings are indeed modern forgeries, rather than dating to the seventeenth century. In addition, discuss how the expectations of an investigator might influence the conclusions that person draws. For each of the scientific tests performed in this case, how might experimental design protocols be established to prevent bias from influencing the outcome?
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