Chemical Education Today
Reports from Other Journals
News from Online: Chemistry and Art by Carolyn Sweeney Judd
How do we describe a work of art: color, line, and texture? How about Neutron Activation Analysis (NAA)? Neutron Activation Analysis NAA has helped track copper archeological finds to specific copper mines. Go to the Art Attack page of the WhyFiles to read about this detective work http://whyfiles.org/081art_sci/ 4.html. Richard J. Cashwell explains NAA at the Website of the College of Engineering of the University of Wisconsin– Madison http://reactor.engr.wisc.edu/UWNRNAA.htm. NAA is based on the detection and measurement of characteristic gamma rays emitted from radioactive isotopes produced in the sample upon irradiation with neutrons. This emitted radiation is a ‘fingerprint’ of the element, and a report is issued giving elemental concentrations in the unknown sample. Once the exact proportions of important trace elements are known, samples can be compared to existing ones, and to each other. Because copper from different mines contains different combinations of trace elements, NAA allows the tracing of archeological artifacts to specific copper mines. Look at the animation of the NAA process, which is shown at http://reactor.engr.wisc.edu/pics/naaprcs.gif and is captured below. Back at the Art Attack page of the WhyFiles site http:// whyfiles.org/081art_sci/3.html, we find eight high-tech ways to do research about art. Let’s consider carbon dating. Carbon Dating The Cave of Chauvet–Pont-D’Arc was discovered in France in 1994, http://www.culture.fr/culture/arcnat/chauvet/ en/index.html. Go to this site to see the beautiful artwork from ancient times. Learn that Accelerator Mass Spectrometry (AMS) was used to date the charcoal from the cave drawings around 30,000 years before present http:// www.culture.fr/culture/arcnat/chauvet/fr/index.html. A clear explanation of how a radiocarbon age is measured using radiometric counting and accelerator mass spectrometry (AMS) can be found at the Rafter Radiocarbon Laboratory Institute of Geological and Nuclear Sciences page http://www.gns.cri.nz/atom/rafter/measure.htm.
Figure 1. Screen from an animation of neutron activation analysis by Richard Cashwell; http://reactor.engr.wisc.edu/ pics/naaprcs.gif
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Accelerator mass spectrometry (AMS) does not rely on radioactive decay to detect the 14C but instead counts the 14 C atoms in the samples as well as 13C and 12C. The small samples required for AMS mean that it is possible to remove a sample for dating without significantly damaging the object. X-ray Fluorescence Let’s look at another method of elemental analysis used by museums: X-ray fluorescence, http://whyfiles. org/081art_sci/5.html. There are distinct advantages of Xray fluorescence: it can operate outside a reactor and it is non-destructive. X-ray fluorescence has been used to detect forgeries: for instance, “antique” silver and “Old Masters” paintings. But concern about forgery is not the only reason to investigate a work of art. WhyFiles also tells the story of A painting being X-rayed “The Feast of the Gods”, a (www.artmuseums.harvard.edu/ 16th century masterpiece renaissance/). Photograph by painted by Bellini, modified Gianfranco Pocobene and Ron Spronk, copyright © The Presiby Dossi, and finally redent and Fellows of Harvard painted by Titian. See the re- College (Harvard University Art sulting X-radiograph as well Museums). [Web site graphic as the painting as it looks now supplied at low screen at the National Gallery of Art resolution.] in Washington, DC http:// www.nga.gov/collection/gallery/gg17/gg17-1141.0.html. Another wonderful, inclusive site is WebExhibits http:// webexhibits.org/feast/ where great details are given about the investigation of this painting. Go to the Harvard University Art Museums site http:// www.artmuseums.harvard.edu/Renaissance/iframes.html for more about analyzing paintings with instrumental analysis. Polarized Light Microscopy Return to the WhyFiles http://whyfiles.org/081art_sci/ 3.html and this time consider polarized light microscopy for pigment analysis. Here Walter McCrone reminds us that “analytical techniques cannot prove that somebody actually painted a work of art. They can, however, rule out that possibility, by proving that the materials used were unavailable when it was supposedly painted.” Go to http://www.mcri.org/ Shroud.html to read of the McCrone Research Institute investigation of the Shroud of Turin. More about polarizing light microscopy is at http:// www.sewanee.edu/chem/Chem%26Art/MS/main.htm. Janet L.
Journal of Chemical Education • Vol. 78 No. 10 October 2001 • JChemEd.chem.wisc.edu
Chemical Education Today edited by
Carolyn Sweeney Judd Houston Community College Houston, TX 77004
Schrenk and John L. Bordley developed the course, Chemistry and Art, at The University of the South with NSF support. The practice pages where you can test yourself on pigment identification are really wonderful. Did I mention that there were movies here also? Web Sites Devoted to the Arts Go back to The WebExhibits Creative Arts page http:// webexhibits.org/dir/a/index.html for a select group of reviewed sites devoted to the arts. Go to WebExhibits: Pigments through the Ages http://webexhibits.org/pigments/. Let’s try Egyptian Blue http://webexhibits.org/pigments/indiv/overview/ egyptblue.html. Here you can learn about the history of the pigment, how to make it, and its chemical composition. From West Jessamine High School in Kentucky comes a great site on pigments called The Chemical Artist. Start with the color Red: http://www.jessamine.k12.ky.us/wjhs/ curriculum/apchem/katie/red.html. Learn that vermillion is a red that was produced from cinnabar, an ore of mercury— and lots more. Go to the Arts Foundation of Michigan to see step-by-step photographs of how to make a fresco http:// www.artservemichigan.org/fresco/afm/fresco.html.
Neutron Activation Analysis http://whyfiles.org/081art_sci/4.html College of Engineering/ University of Wisconsin-Madison http://reactor.engr.wisc.edu/UWNRNAA.htm Neutron Activation Analysis process http://reactor.engr.wisc.edu/pics/naaprcs.gif The Cave of Chauvet–Pont-D’Arc http://www.culture.fr/culture/arcnat/chauvet/en/ index.html http://www.culture.fr/culture/arcnat/chauvet/fr/ index.html Rafter Radiocarbon Laboratory Institute of Geological and Nuclear Sciences page http://www.gns.cri.nz/atom/rafter/measure.htm “The Feast of the Gods” http://whyfiles.org/081art_sci/5.html X-ray fluorescence National Gallery of Art in Washington, DC http://www.nga.gov/collection/gallery/gg17/ gg17-1141.0.html WebExhibits http://webexhibits.org/feast/ Harvard University Art Museums site http://www.artmuseums.harvard.edu/Renaissance/ iframes.html
access date for all sites: August 2001
Carolyn Sweeney Judd teaches at Houston Community College, 1300 Holman, Houston, TX 77004; email:
[email protected].
Polarizing Light Microscopy http://whyfiles.org/081art_sci/3.html McCrone Research Institute http://www.mcri.org/Shroud.html Chemistry and Art at The University of the South http://www.sewanee.edu/chem/Chem%26Art/MS/ main.htm Pigments/Paints WebExhibits: Pigments through the Ages http://webexhibits.org/pigments/ Egyptian Blue http://webexhibits.org/pigments/indiv/overview/ egyptblue.html West Jessamine High School in Kentucky: The Chemical Artist http://www.jessamine.k12.ky.us/wjhs/curriculum/apchem/ katie/red.html Gamblin Artists Colors http://www.gamblincolors.com/book.html General Sites WebExhibits Creative Arts page http://webexhibits.org/dir/a/index.html The Arts Foundation of Michigan: Fresco http://www.artservemichigan.org/fresco/afm/fresco.html Science and Art at the Indianapolis Museum of Art http://www.ima-art.org/education/schoolprograms/science/ index.html The American Institute for Conservation of Historic and Artistic Works http://aic.stanford.edu/treasure/
JChemEd.chem.wisc.edu • Vol. 78 No. 10 October 2001 • Journal of Chemical Education
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World Wide Web Addresses
Art Attack page of the WhyFiles: Detection Tools http://whyfiles.org/081art_sci/3.html
A fine summary site on Science and Art is found at the Indianapolis Museum of Art http://www.ima-art.org/ education/schoolprograms/science/index.html. Learn about paints, painting techniques, and how scientific processes have affected artists’ techniques. A site with a good history of paints is Gamblin Artists Colors http://www.gamblincolors.com/book.html. The Smithsonian Institution selected Gamblin to recreate formulas for oil colors commonly available to painters of the 18th and 19th centuries. This site compares the paints available to the Old Masters and modern artists and discusses the impact of these paints on the techniques used by artists. Finally, we all need to take care of our treasures. The American Institute for Conservation of Historic and Artistic Works has a site devoted to the restoration, preservation, and care of treasures at http://aic.stanford.edu/treasure. Further information about restoration and preservation can be found at many museum Web sites.
