F. E. Rogers
Universitv of Davton Dayton, Ohio 45409
I
Chemistry in Art Radiochemistry and forgery
Vermeer, Van Meegeren, Xeisch, the 17th Century Dutch Master, the 20th Century Artis& Forger, and a scientist, are strange bedfellows but all played an important role in one of the greatest art forgeries in the history of painting. Han van Meegeren born in the Netherlands in 1889 was a gifted draughtsman a t an early age and as an adult was schooled in the classical methods of Dutch Art. So steeped in the academic aspects of art that he enjoyed only moderate success in an age that was undergoing an artistic revolution initiated by men such as Cezanne, Braque, and Picasso. His style was a throwback to an earlier age, but 20th Century man was looking in another direction. In 1935 he would begin a new phase of his career; a venture that would have repercussions in the art and science world for the next 30 odd years. With a certain amount of bitterness Varr Meegeren realized that the art buying public equated the "right name" with intrinsic quality and vice versa. What devilish fun he could have with these hypocrites by signing his paintings Vermeer instead of Van Meegeren, and what a handsome profit he could make in the bargain. The stage was set. He would have to study the subtleties of Vermeers style, obtain some canvas from old paintings, and prepare those pigments characteristic of the time of Vermeer. The results of this clandestine operation would appear in 1937 when Dr. Abraham Bredius, a noted art expert would announce that he had discovered what was perhaps Vermeer's greatest painting, "Christ and His Disciples at Emmaus" (see Fig. 1). So successful was the forgery that the painting had to be restored before the officialunveiling a t the Boyman's
Museum in Holland. Van Meegeren enjoyed the adulation given the painting and also the $280,000 i t netted. He would continue developing his masterful technique of producing forgeries until he amassed a fortune estimated at close to three million dollars. The charade ended in 1945 when Van Meegeren being tried as a Fascist Collaborator declared publically that he had forged six Vermeers. A stunned body of experts, their reputations clearly on the line, declared Van Meegeren a liar. Han died in 1947 without receiving credit as the painter of "Emmaus." Considerable controversy ensued; Paul G. Coremans, a Belgian chemist who from the beginning maintained that the painting was a forgery, had difficulty in selling his case against Vermeer authorship for the painting. I t wasn't until 1968 when Bernard Keisch of illellon Institute presented unequivical radiochemical evidence which proved "Emmaus" was indeed a contemporary painting. This would close the case and verify the work of the Belgian chemist, P. G. Coremans. The radiochemical investigation centered on the white lead pigment used by Vermeer and Van Meegeren. In nature, lead ore contains uranium which s l o ~ l y disintergrates giving rise to the abbreviated radioactive series shown below
where the half-lives are in y = years, d = days, m = minutes and s = seconds. Eight elements in the series decay with the loss of an alpha particle (a helium nucleus) so that the mass number decreases by 4. The other mode of decay is emission of a beta particle (a nucleus electron), the mass of the nucleus is substantially unaltered but the atomic number increases by 1. The parent of the series U-238 with a half life of almost one-half billion years supports all the less stable descendants which gradually are transformed to lead206. The focal point of the chemical analysis that would support Van Meegeren's claim was the balance between two members of this series that are components of white lead pigment; radium-226 and lead-210. If we represent the uranium series in the following way A-B-C-D 10'
"Christ ond His Disciples at Emmow" by H. Yon Meegeren I1 889-1947]. Originally attributed by Jon V e r m e e r 11 632-751. Icourtery of the B ~~~~~i~~~~M~ U S ~ U ~ ~ , ~ n ~ ~ ~ d ~ ~ ~.
Figwe 1 .
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%here the indicated half lines are in arbitrary units and program this consecutive reaction on l ~ ~ ~ ~ an analog
- -
Figure 2. Anolog computer graphs of reaction: A B --r C the half-life ratio is, tl/,(A) :ll/z(B): tl/,(C) = 1 01: 1 :lo-'.
D where
computer, we obtain the curves of Figure 2. At equilibrium the radioactive concentration of B and C are equal. This is the relationship between radium-226 and lead-210 up to the time the lead ore is refined and converted to the white pigment. During this purifica-
tion most of the radium is removed. The lead-210, now unsupported by radium, decays with its characteristic half life (22 yr) until it comes into equilibrium with the small amount of radium remaining. Thus if 99% of the radium is removed it will take about 150 yr for the lead-210 to come into equilibrium again with the radium. Now, if Vermeer did paint "Emmaus" around 1650, certainly the radium-lead balance would have been restored by 1960. It wasn't. In fact the imbalance between the two elements showed the painting to be contemporary, the product of Van Meegeren, not Vermeer. Science has provided yet another obstacle in the path of the would-be art forger, who will no doubt rise to the challenge. Selected General References K ~ m c nB., , FELL~R R., L.,LEVINE,A. S., EIIWARDB, R. R.,Science. 155,1238
\."-.,.
(1QR7)
Karst", B.. Science, 160,413 (1968). C o n m ~ ~P., s ,"Van Meegeren's Faked Vermeera and DeHooghs." Msulenhoff. Arnsterdem, 1949. JEPPBON, L.. .'The Fabulous Frauds," Weybright and Tallev, New York. 1970.
Volume 49, Number 6, June 1972
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