SCIENCE & TECHNOLOGY Jacobs, a senior conservation officer at the British Library in London and one of Clark's collaborators. Raman spectroscopy is particularly wellsuited for nondestructive analysis of the bibles, compared with other methods such as X-ray fluorescence or diffraction, because it provides molecular information rather than just elemental analysis. "The large size of the bible itself can put limits on instrument geometry, as the book canHE GUTENBERG BIBLES HOLD AN "We wanted to determine how diverse not be opened completely flat," Chaplin exalted place in publishing histhe palette of different Gutenberg Bibles says. The use of fiber-optic cables for the tory as the earliest examples of might be, given that they were not all illuspectroscopic analysis makes the awkward books that were printed rather minated in the same city or at the same size and shape of the book less of a probthan hand copied. The printing date," says lead author Tracey D. Chaplin, lem because samples need not be taken of the Gutenberg Bibles was completed in a postdoc in Clark's lab. from the books. In any case, the team re1455- Of approximately 180 copies, subThe analysis is part of a larger project ceived permission to remove small samstantial portions of 48 survive in collecat the British Library to study illumiples from the gutters and margins of copies tions around the world. nated "incunabula" (15th-century printheld at other places for analysis back at the "In view of the enormous amount of arted materials) and the technical and arBritish Library historical and other research carried out tistic developments that occurred as The spectroscopic results showed that on many Gutenberg Bibles over the past six printing began to supersede handwritthe palettes of all seven copies are simicenturies, it is amazing that no attempts ten manuscripts. "At the time the bibles lar and "rather limited," Chaplin says. The have been made previously to identify the were printed, the intention was that pigments used," says Robin J. H. palette for the King George 111 Clark, a chemistry professor at Unicopy contains nine pigments (plus versity College London. gold leaf), three of which were Clark and his coworkers have found in all copies examined and rectified that situation. They used two others that were found in six Raman spectroscopy to examine of the copies. The other copies althe illuminations (decorations) and so contain pigments that weren't inks in a copy of the Gutenberg found in the King George I I I Bible held at the British Library, copy known as the King George III copy The copy housed at the Niederand compared its pigment palette sachsische Staats und Univerwith those of six other copies held sitâtsbibliothek, in Gôttingen, elsewhere in England, France, and Germany, has the most extensive Germany {Anal. Chem. 2 0 0 5 , 77, palette of the seven copies exam3611). Previous studies of the bibles ined, with 16 pigment-related mahave focused on the composition terials identified. That copy was of the printing inks and paper. also printed on vellum—a more expensive material—rather than After the bibles were printed, paper. Vellum is not necessarily an many parts, including the headlines, indication of luxury, however, as rubrics, and major capitals, needed it was sometimes chosen for its to be added by hand. In addition, durability some of the copies were richly illuminated with elaborate borders and For modern purposes, knowing other illustrations. Because these which pigments were used is critadditions varied, they are believed ical for conservation efforts, Clark to have been performed locally to says. "Use of incorrect pigments, the buyer's specifications rather even if they are of the correct colthan coordinated byjohann Gutenor, could destroy any work of art berg's workshop. through adverse chemical reactions. It is vitally important that The pigments used for the handthese critical facts are brought to drawn portions of the bibles are a GOOD BOOK The palette of the King George III copy the attention of the art world as potential source of information of the Gutenberg Bible, housed at the British Library, well as to those in science," he about the books and their time, in- contains nine pigments. The first page of the cluding possible trade routes and prologue, containing St. Jerome's introductory letter, says. "Pigment degradations — common with lead and copper artists' preferences. A standard is shown here. model book offered guidance in pigments —are simply chemical terms of style and pigments, but the dithese early printed books should physireactions, which need to be recognized versity in the finished products suggests cally resemble the traditional book form, for what they are and studied as such."— that the guidelines weren't always followed. the handwritten manuscript," says David CELIA HENRY
ILLUMINATING ILLUMINATIONS
Raman spectroscopy reveals the pigment palettes used to illustrate Gutenberg Bibles
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