National GalleryTechnical Bulletin volume 31

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All rights reserved. No partofthis publication maybe BERLIN Kupferstichkabinett ©Photo Scala, /BPK, transmitted in anyformorbyany means, electronic or Bildargentur für Kunst, Kultur und Geschichte,Berlin: fig.34, p. 21 mechanical, including photocopy, recording,orany CAMBRIDGE ©, Cambridge: fig.51, p. 31 information storageand retrieval system, without the prior permissioninwriting of the publisher. CANTERBURYRoyal Museum and ArtGallery©The National Gallery, London /courtesy of RoyalMuseum and ArtGallery, Articles published online on the National Gallerywebsite Canterbury: fig.3,p.79; fig.17, p. 85; fig.20, p. 86; fig.21, p. 86; maybedownloaded for private studyonly. fig.28, p. 88; fig.31, p. 91; fig.33, p. 92 CAVA DE’ TIRRENI Badia della SS.Trinità photo ©Antonio Biasio: First published in GreatBritain in 2010 by fig.29, p. 90; fig.30, p. 90; fig.32, p. 91; fig.34, p. 92 National GalleryCompanyLimited EDINBURGH The National GalleryofScotland, Edinburgh St Vincent House,30OrangeStreet ©National Galleries of Scotland: fig.52, p. 31 London WC2H 7HH FLORENCE Galleria degli Uffizi, Florence,Gabinetto dei Disegni edelle www.nationalgallery. co.uk Stampe ©Soprintendenza Speciale per il Polo Museale Fiorentino, Gabinetto Fotografico,Ministero per iBeni eAttività Culturali: fig.49, British LibraryCataloguing in Publication Data p. 29; fig.54, p. 32; fig.55, p. 34; Museo del Bargello ©Photo Scala, Acatalogue record for this journal is available from Florence –courtesy of the Ministero per iBeni eAttività Culturali: the British Library fig.38, p. 24; fig.39, p. 25; San Lorenzo©DeAgostini Picture Library/Scala, Florence: fig.6,p.10. ISBN 978 185709 495 4 KASSEL ©Staatliche Museen Kassel: fig.17, p. 107 ISSN 0140 7430 1018117 LONDON ©The Trustees of The British Museum: fig.53, p. 31; Victoria and AlbertMuseum, London Project managerJan Green ©V&A Images/Victoria and AlbertMuseum, London:fig. 41, p. 25 Editor Rebecca McKie OXFORD Christ Church, Oxford ©Bypermission of the governing Designer Libanus Press body, Christ Church, Oxford: fig.33, p. 21 Picture research Karolina Majewska and Suzanne Bosman PA SADENA, CALIFORNIA ©The Norton Simon Foundation, Production Jane Hyne and PennyLeTissier Pasadena, California: fig.4,p.100 Repro by Alta Image, London Printed in Hong Kong by Printing Express PISTOIA Duomo ©Photo Scala, Florence: fig.40, p. 25 PITTBURGH, PENNSYLVA NIA ©Carnegie Museum of Art, Pittsburgh: fig.3,p.66 FRONT COVER ROUEN ©Musée des Beaux-Arts de Rouen: fig.1,p.78; fig.35, p. 95 , TheVirgin and Child with TwoAngels, NG 296, detail of fig.18, page 16

TITLE PA GE Andrea del Verrocchio, TheVirgin and Child with TwoAngels, NG 296, photomicrographs (see page 17 for details) TwoCopies of Perugino’s Baptism of Christ

helen howard and scott nethersole

On 8March 1495, wascontracted to nowinEnglish collections, one in the National Gallery paint an altarpiece to decoratethe high altar of the (NG 1431, FIG.2), the other in the CanterburyCity

Benedictine AbbeyofSan Pietro in by the abbot Museums (FIG.3). The former wasbought for the of the monastery, Lattanzio di Giulio da Firenze.1 He was Galleryin1894 as an autographwork by Perugino to receive 500 largegold ducats for the panels, making himself; the latter hung for awhile in the National it one of the most expensive altarpieces commissioned Galleryinthe 1880s. It wasthought to be awork by in the fifteenth century. 2 In the following century, the (1469–1523), until denounced as a altarpiece wasseen by Vasari, whoobservedthatitwas forgerybySir Frederic Burton, the Gallery’sdirector painted in oil and was‘full of fine efforts’. He also singled from 1874 to 1894. In 1905, it wasoffered to the Royal out the predella for special attention, for it was‘worked Museum in Canterburybyits owner,Gerard Frederick with much diligence’.3 It included three narrativescenes de Zoete.Asimilar fate befell NG 1431, which was showing the ,the Baptism of Christ revealed to be anineteenth-centuryfakewithin several

(FIG.1)and the Resurrection of Christ (all nowinthe yearsofits acquisition.4 But scientific investigation of Musée des Beaux-Arts, Rouen). the techniqueofthe twopaintings can nowshow Twocopies of Perugino’spredella of the Baptism are thattheydatefrom no later than the mid-eighteenth

FIG.1Pietro Perugino, TheBaptism of Christ, c.1497. Oil on wood, 39 × 68 cm. Rouen, Musée des Beaux-Arts, inv. 803-35.

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FIG.2Attributed to Sassoferrato, TheBaptism of Christ (NG 1431), 1630–50. Oil on canvas, 32.5 × 59 cm.

FIG.3After Pietro Perugino, TheBaptism of Christ,probablylate16th or early17th century. Oil on canvas, 30 × 60.5 cm, Canterbury, RoyalMuseum and ArtGallery, InventoryCANCM 4030.

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century, if not considerably earlier.5 The following pages support(FIGS 5and 6). Examination of an end-grain will initiallyconsider the techniqueand attribution of section of the panel identified the timber as poplar, each copy, before exploring howarelative chronology which wasprepared with acalcium carbonate ground, can be established by acombined analysis. It will also identified by energy dispersive X-ray analysis (EDX) in be proposed thattheir different palettes reveal important the scanning electron microscope (SEM).6 Infrared information about the changing state and legibility of reflectography (IRR) did not reveal anyunderdrawing the original. or incision (FIG.7). The canvasitself wasprepared with awarmpinkish ground composed of lead white with earth pigments – Technique of the National Gallerycopy including green earth –inoil, applied in twolayers(FIG. 8). The lowerlayer appearsdarker and browner in hue, X-radiography of the confirmed thatthe as it is enmeshed with the canvasfibres. The colour of picture wasexecuted on acanvassupport–indeed the ground layerisclearlyvisible in thinlypainted areas the impression of the stretcherbarsisevident around and small zones of wear and damage, particularlyinthe the perimeter (FIG.4). The coarse canvasweave,so skyand distant landscape.The influence of the coloured clearlyvisible in the X-radiograph, is also apparent ground is profound and most obvious where the paint is through the ground and paint layers,particularlyinthe thin, as in the receding mountains where the warm lowerportion of the painting when viewed in raking pinkish ground colour interacts opticallywith the over- light. The canvaswas subsequentlyadhered to apanel, lying blue-green to produce acool neutral tone (FIG.5). and the dark stains nowvisible in the skymay result Close examination of the surface revealed distinct from the process of gluing the canvastothe wooden gritty particles in the blue drapery, particularlythatof the figure at farright. Analysis of apaint cross-section taken from adark shadowinthis area confirmed the presence of largeparticles of natural azurite combined with much smaller particles of natural

and alittle vermilion (FIG.9). The medium, identified as heat-bodied linseed oil, has darkened substantiallyand the tinyparticles of ultramarine thatsurround the large azurite particles are onlyclearlyvisible in ultraviolet

(UV) light (FIG.10). Elsewhere,azurite wasemployedto produce arich dark blue by applying the paint over a dark underpaint of vermilion combined with carbon FIG.4Attributed to Sassoferrato, NG 1431, X-radiographdetail showing the canvasapplied to the poplar panel. black for the wing of the angel to Christ’sleft. This dark

FIG.5Attributed to Sassoferrato, NG 1431, detail showing the FIG.6Attributed to Sassoferrato, NG 1431, detail of foliage. warm pinkish ground showing through damagesand thinly painted areas of the skyand distant landscape.

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FIG.7Attributed to Sassoferrato, NG 1431, digital infrared reflec- togram of FIG.2.Detail of Christ and the Baptist.

FIG.8Attributed to Sassoferrato, NG 1431, cross-section of a sample taken from an area of yellowdrapery. The warm pinkish ground composed of earth pigments with alittle lead white in oil has been applied in twolayers.

FIG.9Attributed to Sassoferrato, NG 1431, cross-section of a sample taken from the dark blue shadows of the cloak of the figure at the extreme right of the panel, where azurite wascombined with natural ultramarine and afew particles of vermilion.

FIG.10Attributed to Sassoferrato, NG 1431, cross-section of the sample shown in FIG.9 photographed in ultraviolet light. Here the tinyparticles of ultramarine thatsurround the largeazurite particles are clearlyvisible.

NATIONAL GALLERYTECHNICAL BULLETIN VOLUME 31 | 81 Helen Howard and Scott Nethersole underpaint would have servedtoincrease the covering Analysis of colourless particles within the grey matrix powerofthe mineral blue and would also have provided by SEM-EDX suggested the presence of calcite,sodalite aslightlypurple cast to the overlying layer(FIG.11). The or other Na-Al-Cl silicates, diopside,muscovite/ortho- blue paint layerhas been applied with confident brush- clase and phlogopite (or biotite), all minerals commonly strokes, following the contoursofthe wing and render- associated with natural ultramarine. ing the featherytexture in lowimpasto.Azurite wasalso The skyiscomposed of small quantities of finely employedfor the tunic of the figure second from left ground ultramarine combined with lead white,seen in

(FIG.12). Here,aselsewhere,the blue colour is now the lowest layerofasample taken from the foliage almost completelyobscured by the darkened medium. at upper right (FIG.14). The paint of the skywas applied By contrast, finelyground natural ultramarine was in broad, brisk, horizontal brushstrokes which barely selectedfor the mid-blue draperyofthe kneelingangel coverthe canvastexture and warm pinkish ground third from right (FIG.13). The uppermost surface of this in some areas and are made more pronounced by the paint layershows signs of blanching,and the ultra- darkened varnish which has accumulated in the marine appearstobeofrather lowquality,with just a hollows (see FIG.5). fewblue lazurite particles visible in an overall grey matrix. Athird blue pigment, blue verditer (artificial

FIG.11Attributed to Sassoferrato, NG 1431, cross-section of a sample taken from the dark blue of the wing of the kneeling angel to the left of Christ. Natural azurite has been applied over adark underpaint of vermilion combined with carbon black.

FIG.13Attributed to Sassoferrato, NG 1431, cross-section of a sample taken from the mid-blue draperyofthe kneeling angel third from right.The bindingmedium appearstohave darkened substantiallywhile the uppermost surface of the paint layer shows signs of blanching.

FIG.14Attributed to Sassoferrato, NG 1431, cross-section of a sample taken from the dark green foliage at top right. The sky, painted in ultramarine combined with lead white,isvisible at the FIG.12Attributed to Sassoferrato, NG 1431, detail showing the base of the sample.Overthis is alayer of verditer combined with dark blue draperyofthe figure second from left. yellowtoproduce the green foliage.

82 |NATIONAL GALLERYTECHNICALU B LLETIN VOLUME 31 TwoCopies of Perugino’s Baptism of Christ azurite,identified by polarised light microscopy(PLM), SEM-EDX and Fourier transforminfrared (FTIR) microspectroscopy), wascombined with yellowtopro- duce the rich dark green foliage –towhich final touches are added in distinctlyhigh impasto –inthe upper right- hand corner of the painting (FIG.14). The characteristic small particle sizeand distinctive spherical structure of this artificial precipitated copper pigment is evident in the backscattered electron SEM image (FIG.15). EDX FIG.16Attributed to Sassoferrato, NG 1431, cross-section of a mapping of the sample also confirmed the presence of a sample taken from the brilliant yellowdraperyofthe angel at lead-tin yellowpigment, afew tinyparticles of natural Christ’sright proper side.Raman microspectroscopyand SEM/EDX confirmed the presence of lead-tin-antimonyyellow ultramarine and asignificant amountofcalcium (prob- in this paint sample. ably in the formofchalk) in the pigment mixture.In other instances where chalk has been identified in Thus, the threeblue pigments identified are all combination with verditer,ithas been interpreted as a consistent with aseventeenth-centurydate. Perhaps substratefor ayellowlakepigment, and this mayalso be even more revealing,however,was the identification, the case here.7 However, it is also possible thatthe chalk by Raman microspectroscopyand SEM-EDX, of lead-tin- originates from the process of manufacture,since antimonyyellow, since use of this pigment appearsto chalk is employedinthe reaction and maynot have been have been most common in of the seventeenth completelywashed away at the end of the process.8 century. 11 The pigment wasemployed, for example,for The identification of natural ultramarine and the yellowdraperyofthe figure on the right side.Here azurite in the palette,and the striking absence of the paint has apronounced granular texture,with semi- modernblue pigments –not even Prussian blue,which translucent particles projecting abovethe surface.These wasknown from about 1704–10 –helped to confirm particles are clearlyvisible in the cross-section (FIG.16), thatthe painting dated from before the nineteenthcen- and are typical of the pigment, which is characterised tury. Natural azurite wasrarelyused after about 1700, by aheterogeneous composition of lead-tin-antimony and finelyground ultramarine such as thatfound here oxide suspended in aglassy matrix of lead and silica.12 is typical of seventeenth-centurypractice.Although Seventeenth-centuryexamples of the use of the afew sixteenth-centuryoccurrences are known,9 the pigment include Pietro da Cortona’s Saint Cecilia artificially produced copper pigment verditer wasmore (NG 5284); Salvator Rosa’s Landscape with Mercury commonlyemployedinthe seventeenthcentury. 10 and the Dishonest Woodman (NG 84); and, significantly, Sassoferrato’s TheVirgin and Child Embracing (NG 740) painted around the mid-seventeenthcentury.

Attribution and dating

Nothing is known of the historyofNG1431 before Sir Edward Poynter acquired it from Godfreyvon Kopp in in 1894. Style,then, is the best guide to its maker. But the attribution of copies is adangerous endeavour,if onlybecause the copyist seeks to suppress his or her own idiosyncrasies in imitation of another.The onlyopportu- nity for isolating an individual hand lies in the small deviations from the prototype,which in NG 1431 occur FIG.15Attributed to Sassoferrato, NG 1431, backscatter scanning largelyinthe formofthe faces and the leavesofthe trees electron image of sample shown in FIG.14. Here the distinctive spherical structure of the artificial copper blue pigment is evident. (compare FIGS 1and 2). The pinched features of Christ in

NATIONAL GALLERYTECHNICAL BULLETIN VOLUME 31 | 83 Helen Howard and Scott Nethersole the Rouen picture,for example,have inflated into the year before his birth), suggests thathedid not need to be more rounded forms of NG 1431, typical of Sassoferrato. in Perugia to complete these copies, unless he was The trees, too,are characteristic of his work. Unlikethe replicating the works second hand (i.e.from the copies fine,almost shimmering quality of Perugino’sleaves, by Cavalier d’Arpino or others). The issue is further those of the National Gallerypicture have increased in confused by the various replicas which Sassoferrato sizeand seem to be pressed against the surface of the executed after the Madonna del Giglio,avenerated canvas, not unlikethose of Sassoferrato’s Virgin and attributed to Giovanni di Pietro (known as ‘’) Child Embracing,also in the National Gallery(NG 740),13 thatwas detached from the wall of its ruralchapel and and where,asmentioned above, the unusual pigment transferred to San Pietro in 1643, the same year that lead-tin-antimony yellowhas also been identified. Sassoferratocompleted his most famous commission, It is not onlythe evidence of style,however,that the Madonna del Rosario for Santa Sabina in Rome.One suggests an attribution to Sassoferrato. He is, of course, of these –now lost –was commissioned by Urban known to have produced copies of works by Perugino, VIII, whohad granted permission for the prototype to be not least the fifteen or so paintings thatheexecuted relocated, but others, including one which is still in the for San Pietro in Perugia, the Benedictine abbeywhich church, seem to have been executed for the Abbot Don housed Perugino’spredella.14 Typical of Sassoferrato, Leone Pavoni between 1632 and 1640, several years these canvases were variouslyinspired by Perugino, before the relocation of the sacred prototype.19 François and others, and include four variations on the Macé de Lepinay, whofirstpublished Sassoferrato’s saints thatonce decorated the same predellafrom which work in Perugia, originallyrejectedthe possibility that NG 1431 wascopied. Almost double original sizeand the copyatSan Pietro could be dated as earlyas1632, on canvasrather than panel, theyshow Scholastica, as the painter wasonly23yearsold. In the opinion of Maurus, Placidus and Flavia.15 the current authors, however, the possibility cannot The attribution of paintings to Sassoferratois be ruled out. Instead, Macé de Lepinayassociated all invariablystylistic,with little surviving documentation the San Pietro canvases with apayment recorded in and very fewsigned works, apartfrom the Portrait of the abbey’saccount books of 29 scudi for ‘twenty Monsignor Ottaviano Prati in the PalazzoBarberini in paintings bought in Rome’, including a Saint Maurus, Rome and the Santa Cecilia in the Musée de Strasbourg. thatwere made in February1649.20 The twenty paint- In the case of the paintings at San Pietro,the attribution ings are sadly–but typically–not described in the libro wasfirstsuggested by earlydescriptive accounts of the economico,nor is the name of their author provided. If church and subsequentlyconfirmed by style.16 The indeed these twenty paintings are those by Sassoferrato attribution to Sassoferratoofthe Saint Flavia is rein- thatsurvive in Perugia, then at least fivehave disap- forced by the survivalofadrawing in the RoyalLibrary peared from the church in the intervening centuries. at Windsor.17 All this, however, does not help with the dating Sassoferrato’schronology,aswell as the dating of of NG 1431; it onlyillustrates the complications of his hypothetical sojournatSan Pietro,isvexed. His fixing Sassoferrato’stime in Perugia. The National time in Perugia is traditionallysandwiched between his Gallerypicture need not, in fact, even have been painted youth in the Marche and the first of his works in Rome in . But if it wascopied in, say, Rome,then which can be dated: the ceiling painting of TheBlessed Sassoferratomust have taken detailed drawings of the Virgin appearing to Saint Francis of Paola for the Minim original, carefullyrecording nuances of colours. The friarsofSan Francesco di Paola (1641).18 It seems survivalofhis drawing after Perugino’s Saint Flavia unlikelythathewould have left the Marches before at Windsor might suggest thatthis washis working his twentieth birthdayin1629. Thus it is generally method, save for the fact thatheseems to replicate assumed, without anydocumentaryconfirmation, that Perugino’scoloursastheywould have appeared he wasinUmbria during the 1630s. However, the having faded with time,asifthe painting were readily fact thatSassoferratoproduced acopyafter Raphael’s accessible during the process of copying.Itwould seem Deposition,which had been removedfrom the Baglioni prudent, then, to date the National Gallerypainting chapel at San Francesco al PratotoRome in 1608 (a broadlytobetween 1630 and 1650.

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Technique of the Canterburycopy determine when the alteration to the painting’ssupport mayhave taken place,but the distinct craquelure The X-radiographofthe structure reveals thatthe visible across the surface maysuggest thatthe canvas

Canterburycopyisalso painted on canvas(FIGS 17 remained on its stretcherfor some considerable time and 18), subsequentlyadhered to awooden support before being adhered to the panel. Evidence from IRR consisting of twolayers: athin panel with asecond, shows no visible underdrawing,though it is clear that thicker,worm-eaten board underneath. It is difficult to the staffofthe Baptist’scross has asingle incised line

FIG.17After Pietro Perugino, TheBaptism of Christ,probablylate16th or early17th century. Oil on canvas, 30 × 60.5 cm, Canterbury, RoyalMuseum and ArtGallery, InventoryCANCM 4030

FIG.18After Pietro Perugino,CanterburyRoyal Museum and ArtGallery, FIG.17, X-radiographshowing the canvas applied to the poplar panel.

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FIG.19After Pietro Perugino,CanterburyRoyal Museum and FIG.20After Pietro Perugino,CanterburyRoyal Museum and ArtGallery, FIG.17, digital infrared reflectogram detail of Christ ArtGallery, FIG.17, detail showing Christ and the Baptist. and the Baptist.

ruled up the right side (FIG.19).21 The ground is composed of lead white with earth pigments, including green earth, to produce apale,warmbrownish-grey coloured ground which is visible where the paint of the water covers the ground sparingly (FIGS 20 and 22). The ground is slightlypaler and less pink in colour than thatemployedfor NG 1431, though it is otherwise rather similar in composition. It is notable thatboth contain green earth. The blue mineral pigment identified in the Canterburypanel is exclusively natural ultramarine,of rather largeand varied particle sizeincomparison with the rather small particles of NG 1431 (FIG.23). The ultramarine shows signs of blanching and this produces arather flattened appearance in the blue drapery, partic- FIG.21After Pietro Perugino,CanterburyRoyal Museum and ularlyinthe cloak of the figure second from left, where ArtGallery, FIG.17, detail showing the unmodulated pale blue draperyofthe figure second from left. Comparewith FIG.12. the colour appearsalmost entirelyunmodulated (FIG.21). In the Canterburycopy, ultramarine wasused both alone and combined with ared lakepigment to produce the rich purple colour employedfor Christ’sloincloth

(FIG.20), and for the draperyofthe angel kneelingto

86 |NATIONAL GALLERYTECHNICAL BULLETIN VOLUME 31 TwoCopies of Perugino’s Baptism of Christ the right of John the Baptist. Forthis intenselypurple The copper pigment identified in the drapery, area, athick layerofred lakecombined with ultra- landscape and water is puzzling.Its structure is varied, marine wasapplied directlyoverthe warm brown and while afew broken, angular forms are present, the ground (FIG.24).22 Redlakewas also employedto majority are small spherical or compressed spherical provide depth to the shaded areas of the red drapery. The particles, as shown in the backscatter scanning electron sample from the shadows of the cloak of the figure at far image (FIG.26).23 Elemental analysis in the SEM left shows athick layerofvermilioncombined with red confirmed the presence of copper,carbon and oxygen in lakeand lead white glazed with pure red lakewhich the outer portion of the particles and, in addition,silica has faded in the upper portion of the layer(FIG.25). and aluminium in the centre of some of the spherulites.

FIG.25After Pietro Perugino,CanterburyRoyal Museum and

FIG.22After Pietro Perugino,CanterburyRoyal Museum and Art ArtGallery, FIG.17, cross-section of asample taken from the red Gallery, FIG.17, cross-section of asample taken from the green draperyofthe figure at farleft. Here vermilion combined with draperyofthe standingfigure second from right. The pale brown- red lakehas been glazed with red laketoproduce the rich red ish ground consists of lead white combined with earth pigments. shading of the drapery.

FIG.23After Pietro Perugino,CanterburyRoyal Museum and ArtGallery, FIG.17, cross-section of asample taken from the mid- blue draperyofthe kneeling angel next but one to the right of the Baptist. Here the natural ultramarineshows signs of blanching in the upper portion of the paint layer.

FIG.26After Pietro Perugino,CanterburyRoyal Museum and ArtGallery, FIG.17, backscatter scanning electron image of the sample shown in FIG.27showing the small spherical or compressed spherical particles of artificially produced verditer.

FIG.24After Pietro Perugino,CanterburyRoyal Museum and ArtGallery, FIG.17, cross-section of asample taken from the dark purple robe of the angel kneeling to the right of Saint John. The rich purple colour consists of ultramarine combined with red lake, applied in athick layeroverthe pale brownish ground.

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The presence of silicates has, in the past, been assumed to be indicative of anatural precipitated source for spherical malachite.24 However, it is also possible that syntheticallyproduced pigments such as blue and green verditer were nucleated on materials such as silicates and, on balance,the structure and extremelysmall par- ticle size(generallyless than 5microns) of the pigment here suggests the presence of asynthetic verditer. This manufactured copper pigment wasemployed on the Canterburypanel to produce awide variety of greens: combined with lead white for the water; with lead-tin yellow, lead white and afew particles of vermil- ion and black for the distant landscape (FIG.27); with lead white and earth pigments for the near landscape; and with lead-tin yellowfor the draperyofthe figure second from right (FIG.28).25 The presence of calcium carbonate in manyofthe paint samples suggests thata yellowlakeonachalk substratemay also have been incorporated. Verditerswere produced in aseemingly infinite variety of hues from blue to green, with the colour produced seemingly largelydependent on the temperature during production. Giventhe complex mixtures in which the pigment wasincorporated it is often difficult to be sure of the original colour employed.

However, documentarysources provide agood deal FIG.28After Pietro Perugino,CanterburyRoyal Museum and of evidence regarding the earlyuse of verditers. For ArtGallery, FIG.17, detail showing the rangeofgreen hues achieved by combining verditer in various pigment mixtures. example John Smith, writing in 1676, recommends yellowcombined with blue verditer for foliage, but suggests green verditer,yellowlakeand lead white for employedincombination with yellowpigments to make drapery. 26 John Barrowindicates thatgreen verditer good greens.28 is, ‘seldom us’dinany thing but colouring landscapes, Again, there is nothingtoindicate thatthe panel which seem afar off...because it is inclined to blue’.27 dates from the nineteenthcentury. Indeed lead-tin Evidence from the analysis of seventeenth-centurypaint yellowdisappearsfrom the palettes of artists all over samples suggests thatverditerwas almost always Europe in the mid-eighteenth century, providing a probable mid-eighteenth-century terminus ante quem for the painting.Further to this, the mid-tone ground layerisconsistent with apainting of the sixteenth or seventeenthcentury, 29 and the presence of verditer is compatible with adatefrom the sixteenth to the eighteenth century.

FIG.27After Pietro Perugino,CanterburyRoyal Museum and ArtGallery, FIG.17, cross-section of asample taken from the distant landscape,showing verditer combined with lead-tin yellow, lead white and afew particles of vermilion and black.

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Provenance and old attribution of the Discussion Canterburycopy Technical examination and analysis of both works has The Baptism wasdonated to Canterburyin1905 by provided firmevidence indicating that, farfrom being Gerard Frederick de Zoete as awork of the Urbinate nineteenth-centuryforgeries, both are copies after painter Timoteo Viti.30 This attribution wasanold one. Perugino probablydating from the seventeenthcentury. The painting’sfirstdocumented appearance is in a Compelling art-historical evidence suggests Sassoferrato Christie’ssale catalogue of 1866, when it wasalready as the author of the National Galleryversion. Further described as the work of ‘Timoteo delle Vite’ and was to this, it maybepossible thatsubtle differences in style thoughttocontain portraits of ‘Raffaelle,Perugino, and painting technique provide sufficient evidence to Cosmo [sic] de Medici’ and the artist himself.31 At that suggest arelative chronology for the copies. point it wasinthe collection of the restorer and dealer ThoughPerugino’s prototype and the copies corre- HenryFarrer (1798–1866).32 It is not known for cer- spond in scale and overall composition, there are certain tain where he acquired the painting,but the catalogue discrepancies in colour and fine detail.35 Neither copy, entryrecords thatitcame ‘From Prince Ferdinand’s for example,retains all the subtle features of the original Collection’. Sadly, Ferdinand is acommon princelyname landscape; instead theysimplify its particularities and in the first half of the nineteenthcentury(witness, flatten its brilliant tonal gradation. But the copies can for example,Prince Ferdinand, DukeofBrunswick, be used to recovervital information about lost portions d. 1806; Ferdinand Iand II Bourbon of the TwoSicilies, of the original. The picture in Rouen, likethe other d. 1825 and 1859 respectively;Prince Ferdinand, Duc twosurviving narrativescenes from the predella(the d’Orleans, d. 1842; or Prince Ferdinand of Saxe-Coburg Adoration of the Magi and the Resurrection)appears and Gotha, d. 1851. No Prince Ferdinand appearsto to have been badlydamagedalong its loweredge. The have had asale in London at this period,although similarity between the Canterburyand National Gallery Farrer wasalso buying regularlyonthe Continent.33 pictures in this area suggest thattheywere executed The nineteenth-centuryattribution to Viti was before the lowermost strip of Perugino’spanel waslost. presumablybased on the deduction thatthe painting As such, theyprovide important evidence for what the wasnot of sufficient quality to be attributed to Perugino foreground landscape might have looked like, as well himself,but wasevidentlydependent on his style.Viti as recording the position and sizeofthe feet. The wasclearlyimpressed by the Umbrianpainter,whose discrepancyisparticularlynoticeable in the left proper influence is most strongly felt in works painted before foot of the figure at farright, which is greatlyelongated 1511 –when his attentions were seemingly transferred and placed further forward in the addition to the Rouen to Raphael –and then again in the last yearsofhis life panel.36 (see,for example,the Brera Annunciation with Saints John Yetbyfar the most telling difference between and Sebastian). The debt to Perugino in the Canterbury Perugino’soriginal panel and the copies is found in picture was, in the nineteenthcentury, unlikelytohave colour variations. The Rouen picture has aluminosity been identified as copying; in all probability it was and clarity of colour imparted by the white ground and revered as an original composition, giventhatthe rela- imprimitura which reflects light through the overlying tionship between NG 1431 and Perugino’spanel in paint layers.37 The use of coloured grounds in both Rouen wasunknown before HerbertHorne unmasked copies has aprofound effect on the overall appearance, it in 1899.34 As such, similarities might have been per- with reduced luminosity and amore muted sense of ceivedbetween such Peruginesque details as the distant colour.Inthe Canterburycopy, the application of the town in the Canterburypicture and the corresponding paint itself is rather flatand uniform, covering the passage in Viti’s Saints Thomas Becketand Martin ground well, but displaying none of the distinct impasto worshipped by Bishop Arrivabene and DukeGuidobaldo da visible in the trees, draperyand landscape of the Montefeltro.Such correspondences are,however,generic National Galleryversion. The receding space in the and not sufficient to supportthe attribution, especially Canterburypanel is articulated with less facility and when the scientificevidence suggests alater date. little aerial .Itisalso altogether greener than

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FIG.29After Pietro Perugino, TheResurrection of Christ,probablylate16th or early17th century. Oil on canvas, c.52 × 82 cm. Cava de’ Tirreni, Badia della SS.Trinità.

FIG.30After Pietro Perugino, TheAdoration of the Magi,probablylate16th or early17th century. Oil on canvas, c.52 × 82 cm. Cava de’ Tirreni, Badia della SS.Trinità.

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its National Gallerycounterpart. There is, however, a set.39 But it is conceivable thatthe Canterburypicture is greater differentiation in the colour of the blue draperies by the same hand. While it has not been possible to take in the Canterburypanel, with hues ranging from pale pigment samples from the works at Cava,tothe naked blue to the near purple of Christ’sloincloth. Despite this eyethe palette seems similar to the Canterbury Baptism. variation in hue,some areas of blue draperyappear flat Theycorrespond, too,interms of style.The delineation and unmodulated, such as the tunic of the figure second of the face of the Baptist in the Canterburypicture from left (see FIG.21). This effect is due,atleast in part, (FIG.31) finds aclose equal in the face of Christinthe to the blanching of the ultramarine pigment. However, Resurrection at Cava (FIG.32), while the profile of one of the extreme flatness here maysuggest thatthe blanched the kneeling angels at Canterbury(FIG.33) is not only appearance of the ultramarine wasalreadyapparent stylisticallyrelated to the Virgin at Cava (FIG.34), but on Perugino’sprototype,and thatthe copyist recorded also demonstrates asimilarity of handling. the muted appearance of the blues. By contrast, in the If the blues are useful in relating the Canterbury National Gallery Baptism,this area of draperyispainted picture to similar works, then the reds might help refine in an impasto of natural azurite,which nowappears its dating.The red lakes employedfor the red drapery very dark blue due to the darkening of the binding showsigns of some fading in both copies, with the palest medium (see FIG.12). highlights, where the pigmentismixed with white and The blanching of the ultramarine in the Canterbury applied over apale underpaint, exhibiting the greatest picture is not dissimilar to the deterioration of the blues loss in colour.40 But it is the use of ared lakepigment in twocopies of the panels which originallyflanked in combination with blue to formpurple hues in the Perugino’s Baptism (FIGS 29 and 30). These canvases, Canterburycopythatismost significant. Though red showing the Adoration of the Magi and the Resurrection, lakeispresent in the palette of both copies and is survive in the Benedictine AbbeyofSantissima Trinità employedasaglazefor the shading of red draperyin at Cava,not farfrom Salerno in southernItaly. 38 They each case,itisnot found mixed with blue to produce are,however,slightlylarger than the Canterburypicture purple in the National Galleryversion. The implication and so it is unlikelythattheyformed partofasingle of this difference is thatareas of purple in the original

FIG.31Detail of the Baptist in FIG.17, after Pietro Perugino, FIG.32Detail of Christ in FIG.29, TheResurrection of Christ CanterburyRoyal Museum and ArtGallery,

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FIG.33Detail of the kneeling angels in FIG.17, after Pietro FIG.34Detail of the Virgin in FIG.30, TheAdoration of the Magi. Perugino,CanterburyRoyal Museum and ArtGallery. had faded to blue by the time NG 1431 wascopied, but parts were nowmore readilyavailable to admire.43 It is thatsome residue of the original colour remained when probable,then, thatthe Canterburycopywas produced the Canterburypicture wasexecuted. In other words, after the original wastaken down, suggesting adate it seems reasonable to propose thatthe National after 1591. Gallery Baptism maybeslightlylater than thatnow in Finally, the dife f rences between the twocopies may the museum at Canterbury. be explained if it is speculated thatthe Perugino’s The evidence of the pigments and ground used in predella wascleaned after its removalfrom the high the Canterburywork points to adateinthe late six- altar,such thatthe Canterburycopywas made before a teenth or seventeenth century, while the National yellowedvarnish wasremovedand the National Gallery Gallerypainting probablydates to about 1630–50 if the version afterwards. Such avarnish would have had the attribution to Sassoferratoisaccepted. This would most marked impact on the pale blues of the riverand provide a terminus ante quem for the Canterburywork in distant landscape in Perugino’soriginal, rendering the second quarter of the seventeenthcentury. Added them green and flattening the aerial perspective,not to these considerations is the fact thatPerugino’s unliketheir representation in the Canterburypicture. altarpiece over the high altar at San Pietro wasdisman- Redlakepigments, which are vulnerable to fading, tled in 1591, when Valentino Martelli reorganised the mayhave been preservedbyayellowvarnish and a Church in line with post-Tridentine ideas.41 Various position abovethe high altar,which (then as now) elements of Perugino’saltarpiece were scattered around presumablyreceivedlittle light. After cleaning and the the church, and towards the end of the seventeenth relocation of the picture to the sacristy,where it century, Lancellotti observedthatthe different panels might have receivedmore light, the lakepigments would of the predella were in the sacristy.42 The removalofthe have been more vulnerable to fading.44 Thus if the predella panels from the high altar would surelyhave Canterburycopywere made beforecleaning it may made them easier to copy; indeed it is debatable whether represent an important record of the rangeofblue and an artist would have been permitted to clamber over purples in the draperyofthe original painting.45 such asacred location to draw them at close quarters. Supposing the National Gallerypanel to be slightly And it is notable thatthe fame of the altarpiece seems to later and copied after ayellowedvarnish wasremoved have increased after its dismembering,asifthe separate from the original, the increased definition and articula-

92 |NATIONAL GALLERYTECHNICAL BULLETIN VOLUME 31 TwoCopies of Perugino’s Baptism of Christ tion of space in the landscape would be expected. Notes The removalofthe yellowvarnish would makethe red lakepigments more vulnerable to fading,which would 1Perugino receivedfinal payment on 6April 1500. The altar was account for the uniformrangeofblues in the drapery, consecrated on 13 January1500, by which date it is safetoassume the panels had been installed. The consecration is recorded by with the red component reduced in anymixed purples. O. Lancellotti, Scorta Sacra,ms. Biblioteca Comunale Augusta di Whether these speculations are accepted or not, the Perugia, before 1671, cited in P. Scarpellini, Perugino,Milan 1984, p. 93. The documents relating to the commission were published scientificevidence rules out the possibility thatthese by F. Canuti, Il Perugino, 1931, vol. 2, pp.176–83. Forthe twopaintings are nineteenth-centuryforgeries. Instead, most recent reconstruction of the altarpiece –firstattempted by W. Bombe in Perugino,Stuttgartand Berlin 1914, p. 49 –see theywere most likelypainted in the seventeenth C. Gardner vonTeuffel, ‘Carpenteria emachine d’altare.Per la century. Thatthe twocopyists interpreted the same storia della ricostruzione della pale di San Pietro ediSant’Agostino aPerugia’, in V. Garibaldi and F. F. Mancini, Perugino il divin pittore, cloth as purple and blue would seem to suggest thatthe exh. cat., Perugia, Galleria Nazionale dell’Umbria, 2004, Canterburypanel predates the National Gallery’s, which pp.141–53. The main panel, showing the Ascension of Christ,is probablydates from about 1630–50, givenastylistic nowinthe Musée des Beaux-Arts, , as is the lunette of God the Father surrounded by Angels and Cherubim.Two painted occuli of the attribution to Sassoferrato. By process of deduction, Prophets Isaiah and Jeremiah survive in the Musée des Beaux-Arts, then, the Canterburypanel waspainted between 1591, Nantes. The three narrativepanels from the predella are in the Musée des Beaux-Arts, Rouen, whilst half-length figures of saints, when the high altarpiece wasdismantled, and about which probablyalso came from the predella, remain in San Pietro, 1630, making its old attribution to Timoteo Viti Perugia (Saints Herculanus, Constantius, Maurus, Peter Vincioli). Saints Benedict, Flavia and Placidus are in the Pinacoteca Vaticana, untenable.Differences between the twopaintings are .The image of Saint Scholastica wasstolen –along with more difficult to account for,and all conclusions must the other predella panels –on28March 1916 and returned to the church in 1993, much damagedand severelycut down. necessarilyremain speculative,but it does seem feasible 2M.O’Malley, TheBusiness of Art: Contracts and the Commissioning to suppose thatPerugino’s panel waseither cleaned Process in Renaissance Italy,New Havenand London 2005, p. 133. 3‘la quale tutta operasivede piena di belle fatiche’; ‘con molta or viewed under different lighting conditions, such that diligenzia lavorate’, , Le vite de’più eccellenti pittori twopaintersseeking to reproduce its forms, colours scultori ed architettori,edited by G. Milanesi, 8vols, Florence 1877, and effects could come to interpret the same landscape Vol. 3, p. 588. 4For an extended discussion of the provenance and scandal in different terms. Ironically, it is through the studyof surrounding these twoworks in the late nineteenth and early copies thatlight can be thrown on the vicissitudes of an twentieth centuries, see S. Nethersole and H. Howard, ‘Perugino, Sassoferratoand a“beautiful little work” in the National Gallery’ original composition. forthcoming in TheBurlington Magazine,June 2010; see also H.P.Horne,‘An inquiryinto twopictures recentlyacquired for the National Gallery’, TheMagazine of Art,1899, pp.241–3. 5Initial examination of the National Galleryversion by JoycePlesters in 1970 raised the possibility thatthe painting might indeed date from before the nineteenth century, and reopened the debate about its date.Further detailed analysis wasundertaken for the exhibition Close Examination: Fakes, Mistakes and Discoveries at the National Gallery, 30 June –12September 2010. 6Poplar panels are common in Italy, where theywere usuallypre- Acknowledgements pared with acalcium sulphate ground. To the naked eye, the panel appearstohave some age, although it wasnot necessarilynew when the canvaswas attached to it. We are grateful to KenReedie of the CanterburyCity 7See A. vanLoon, Color Changes and Chemical Reactivity in Seventeenth-Century ,PhD dissertation, University of Museums for allowing us to takesamples of the Amsterdam, MolartSeries 14, AMOLF,Amsterdam 2008, p. 69. Canterburypanel. We would also liketothank Don 8P.Mactaggartand A. Mactaggart, ‘Refiners’ Verditer’, Studies in Leone Morinelli and Elisabetta Scirocco for their help Conservation 25, 1980, pp.37–45. 9For example,blue verditer has been identified in what are thought at the Badia di Cava,and Livia Schaafsma for her to be original paint layers in Giulio Romano’s TheNurtureofJupiter, assistance at Colnaghi’s. Mark Westgarth kindlyshared paintedinthe mid-1530s, see L. Keith, ‘Giulio Romano and The Birth of Jupiter:studio practice and reputation’, National Gallery with us his largelyunpublished research on Farrer. Technical Bulletin 24, 2003, pp.38–49. We are also indebted to Janet Ambers, Science Group, 10 Indeed, recent analysis of seventeenth-centuryNetherlandish paintings by vanLoon and othershas revealed anumber of exam- Department of Conservation and ScientificResearch, ples, especiallyinmixtures with yellowpigments to produce greens. British Museum, for Raman microspectroscopy, and See A. vanLoon and L. Speleers, ‘The use of blue and green verditer in green coloursinthe mid-seventeenth-centurypaintings of the at the National Gallery, to MarikaSpringfor helpful Oranjezaal’, in Studying Paintings –Technology and comments and references, Practice,postprints of the National GalleryTechnical Bulletin

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30th AnniversaryConference,The National GalleryLondon, document of 1649 is preservedinthe Archivio Storico di San 16–18 September 2009, forthcoming. Pietro, LibroEconomico,1647–50, LE 139. It wasfirstpublished 11 All the examples of lead-tin-antimonyyellowinitiallycharacterised by Macé de Lepinay1976 (cited in note 14), appendix 2, p. 53. fell within the seventeenth century, the majority having some 21 There is also possible use of indirect incision which maysuggest connection with Rome.See A. Royand B. Berrie,‘Anew lead-based the method of transfer of the design, though this is inconclusive. yellowinthe seventeenth century’, in Painting Techniques: History, 22 SEM-EDX analysis suggested thatthe substrateofthe dyestuffis Materials and Studio Practice,Contributions to the Dublin IIC Congress, hydrated alumina. 7–11 September 1998,eds. A. Royand P. Smith, London 1998, 23 The particle structure compares closelywith those identified in pp.160–5; and C. Sandalinas and S. Ruiz-Moreno,‘Lead-tin-anti- Jacob Jordaens’s Frederik Hendrik in Triumph,Oranjezaal ensemble monyyellow, historical manufacture,molecular characterization (1648–1652), The Hague,published in vanLoon 2008 (cited in and identification in seventeenth-centuryItalian painting’, Studies note 7), fig. 2.20. in Conservation 49, 2004, pp.41–52. However, anumber of recent 24 Natural spherical malachite has been identified in anumber of identifications in eighteenth- and nineteenth-centurypaintings instances, generallyinfifteenth- and sixteenth-centurypaintings. makeitclear thatuse of the pigment graduallyspread outside these In all examples of spherulitic malachite identified in fifteenth- geographic and temporal boundaries. See DHradil, T. Grygar, centuryItalian paintings in the National Gallery, the pigment was J. Hradilová, P. Bezdicka, V. Grunwaldová, I. Fogasand C. Miliani, found to be associated with silica and potassium aluminium silicate. ‘Microanalytical identification of Pb-Sb-Sn yellowpigment in Indeed in some examples the malachite appearstohave nucleated historical European paintings and its differentiation from lead on asilicaceous particle.See G. Heydenreich, M. Spring, tin and Naples yellow’, Journal of Cultural Heritage,8,2007, M. Stillhammerova and C.M. Pina, ‘Malachite pigment of spherical pp.377–86, and see article by R. Morrison in this volume particle form’, in Preprints of the ICOM Committee forConservation, pp.112–28. 14th Triennial Meeting,The Hague,12–16 September 2005,I.Verger 12 Royand Berrie 1998 (cited in note 11) characterised the pigment as (ed.), London 2005, Vol. 1, pp.480–8. aternaryoxide of lead-tin-antimony, with acubic pyrochlore-type 25 Lead-tin yellowwas identified by SEM–EDX in anumber of the crystal structure,suspended in alead calcium silicate matrix. mixed greens. 13 Forafull stylistic analysis and comparison of NG 1431 with works 26 J. Smith, TheArt of Painting in Oyl,London 1687, 1st edn, 1676, by Sassoferratosee Nethersole and Howard (cited in note 4). p. 25. 14 The seminal article on these works is F. Macé de Lepinay, ‘A rchaïsme 27 J. Barrow, Dictionarium Polygraphicum,London 1735. Forfurther et purisme au XVIIe siècle: les tableaux de SassoferratoàS.Pietro de discussion of the terminology and sources, see Mactaggartand Pérouse’, Revue de l’Art,31, 1976, pp.38–56. Of the fifteen known Mactaggart1980 (cited in note 8), and vanLoon and Speleers works for San Pietro,nine are in the church, fiveare in the apart- forthcoming (cited in note 10). ment of the Abbot and one is in the collection of the Musée du 28 VanLoon and Speleersforthcoming (cited in note 10). in (inv. 600). 29 See J. Dunkerton and M. Spring,‘The development of paintingon 15 Apainting of the same formatshowing Benedict is anew invention, coloured surfaces in sixteenth-centuryItaly’, in Painting Techniques, despite the survivalofPerugino’soriginal in the church. There are History and Studio Practice,contributions to the IIC Dublin Congress no copies in the church of the narrativescenes from the predella, 7–11 September 1998,A.Roy and P. Smith (eds.), London 1998, nor are anyrecorded. Acopyofthe Baptism was, however, in the pp.120–30. collection of Cavaliere Francesco Maria Azzi in Perugia in 1788; see 30 G. F. de Zoete had acquired the painting through Colnaghi’satthe E. Gardner, Abibliographical repertory of Italian private collections, sale of his father’seffects, see S. Herman de Zoete,Esq. deceased, late Vicenza 1998, p. 57. of Pickhurst Mead, Hayes, Christie’s, London, 8–9 May1885, lot 16 ‘Intorno alla chiesa, chiusa in cornicci di stucco,veggosi molti 335, to Colnaghi’sfor £388.10.0 (370 guineas). quadri de quale alcuni sono copiate benissimo da ottimi originali 31 Catalogue of the HighlyImportant Collection of Ancient and Modern dla pittore cognominato dalla Patria Sassoferratoesono une Pictures, formed during the last forty yearsbythe distinguished connois- Anunziata, una Concezione,unCristo morto portato alla sepoltura seur,Henry Farrer,Esq., F. S.A., Deceased,Christie’s, London,15and eunaltro con Giuditta.’G[iovanni]. F[rancesco]. Morelli, Brevi 16 June 1866, lot 332, to Colnaghi’sfor £236.5.0 (225 guineas). notizie delle pittureescultureche adornano l’augusta citta di Perugia, PresumablyColnaghi’ssold the painting to S.H. de Zoete as they Perugia 1683, p. 5. The first account to mention the copies after would later do to his son, although the transaction cannot be con- Perugino’spredella wasthe third edition of Orsini’sguide,pub- firmed as Colnaghi’sstockbooks from before 1911 do not survive. lished in 1792: ‘Nelle stanze[…] San Benedetto,Santa Scolastica, 32 The most recent, and complete,information on Farrer can be San Mauro,San Placido,Santa Flavia, Santa Maria Maddalena, found at http://www.npg.org.uk/research/programmes/directory- Sant’Agnese,Santa Caterina, Santa BarbaraeSanta Apollonia in of-british-picture-restorers/british-picture-restorers-1630-1950- mezza figure,sono tutte bellissime copie tratte de vari originali f.php. di Raffaello,diPietro Perugino edialtri Valentuomini, dallo stesso, 33 We are grateful to Mark Westgarth for sharing with us his research acuratissimo Sassoferrato.’F.M. Galassi, Descrizione delle pitture on Farrer. di San PietrodiPerugia chiesa de’Monaci Neri di S. Benedetto della 34 See note 4. congregazione casineseediquanto si vede in essa di più singolare, colle 35 The sizeofthe original panel is 39 × 68 cm. Infrared photography notizie de’loroAutori,3rd edn, Perugia 1792, supplement pp.80–1. revealed evidence of precise drawing for the folds of the drapery, 17 A. Blunt and H. L. Cooke, TheRoman Drawings of the XVII &XVIII faces, hands and details of the landscape of Perugino’spainting, Centuries in the Collection of Her Majesty the Queen at Windsor Castle, see unpublished reportno. 1659, Ministère de la Culture et de la London 1960, cat. 887, p. 104, fig. 79. Communication, Paris, 22 January1982. 18 This painting and La Madonna del Rosario are the onlytwo fixed 36 Certain differences between the original and the copies are more points in his oeuvre.The latter,animposing altarpiece commis- puzzling.The gold haloes evident in the Rouen panel are included sioned by Olimpia Aldobrandini for Santa Sabina, Rome,dates in the Canterburycopy, but are missing in the National Gallery from 1643. painting.Also,the Rouen picture appearstobeflanked by decora- 19 Galassi 1792 (cited in note 16) p. 47n, supplement p. 80. Fora tive panels including grey-painted borders, roundelsand rinceaux.It more recent discussion, drawing on Don Leone Pavoni’s Ricordi in is not certain if these are original (especiallysince the colour of the the Archivio Storico di San Pietro,MazzoXCIV,fol. 11v,see Giovan timber would seem to be showing through the paint, suggesting Battista Salvi ‘il Sassoferrato’,exh. cat., Chiesa di San Francesco, thattheyare not on aprepared ground), but theycertainlypredate Sassoferrato, Milan 1990, cat. 57, p. 121. the damage to the lowersection of the painting.Either way,theyare 20 Macé de Lepinay1976 (cited in note 14) pp.39and 53. The not repeated in the twocopies. See fig.35.

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37 Perugino tended to paint on agesso ground with alead white of Austria and Emperor of Mexico,in1854; S. De Stefano, La Badia imprimitura,sometimes with the addition of alittle lead-tin yellow della Santissima Trinità: Guida storica illustrata,Badia di Cava 1903, and finelyground manganese glass. C. Plazzotta, M. O’Malley, pp.79–80. A. Roy, R. White and M. Wyld, ‘The Madonna di Loreto: An 40 Asimilar effect is visibleinPerugino’sprototype.Lakepigments Altarpiece by Perugino for Santa Maria dei Servi, Perugia’, National mixed with white and applied over apale-coloured or white ground Gallery Technical Bulletin 27, 2006, pp.72–95. See also M. Spring, and unprotected by aglazeare particularlyvulnerable to internal ‘Perugino’spainting materials: analysis and context within six- reflection and therefore fade more rapidly. Other factorsaffecting teenth-centuryeasel paintings’, in ThePainting Technique of Pietro the rateoffading include the type of dyestuff, substrateofthe lake Vannucci, called Il Perugino.Proceedings of the LabS TECH and type of organic bindingmedium. See D. Saundersand J. Kirby, Infrastructure Cooperation Network, Perugia, 14–15 April 2003, ‘Light-induced colour changes in red and yellowlakepigments’, B. Brunetti, C. Seccaroni and A. Sgamellotti (eds.), Florence 2004, National Gallery Technical Bulletin 15, 1994, pp.79–97, esp.p.93. pp.21–8. 41 La basilica di San PietroinPerugia intorno all’anno 1591,Perugia 38 S. De Stefano, La Badia della Santissima Trinità: Guida storica illus- 2003. trata,Badia di Cava 1903, p. 63; anon., Descrizione storico-artistica 42 Lancellotti cited by Scarpellini 1984 (cited in note 1), p. 93. illustrata della Badia della Santissima Trinità di Cava,Badia di Cava 43 Seventeenth- and eighteenth-centuryguides to Perugia invariably 1927, p. 39; G. Fiengoand F. Strazzullo (eds.), La Badia di Cava,Cava include them among the city’srich artistic treasures; see,for de’ Tirreni 1990, Vol. 2, pl. 64. It is not known when the canvases example,C.Crispolti, Perugia Augusta,Perugia 1648; G.F.Morelli, arrivedatCava. It is possible thattheywere broughtbyGregorio Brevenotizie delle pittureescultureche adornano l’augusta città di Lottieri, whowas abbot from 1640 to 1642 and wasaPerugian, Perugia,Perugia 1683, pp.47, 53–4; L. Pascoli, Vite de’Pittori, or the Breschian abbot Alessandro Pochipanni(1603–6), who Scultori,Archittetti perugini,Rome 1732, p. 30; B. Orsini, Guida al had ties to the community at San Pietro,Perugia; see Fiengoand Forestieroper l’Augusta città di Perugia,Perugia 1784, p. 32; and Strazzullo 1990 (cited above), pp.64and 66. idem., Vita, elogio ememoria dell’egregio pittorePietroPerugino edegli 39 The Adoration of the Magi measures 58 × 82 cm, while the scolari di esso,Perugia 1804, p. 160. Canterbury Baptism is 36 × 60.5 cm. However, remembering that 44 Exposure to light is the principal reason for the fading of lake the Canterburypicture is known to have been in the collection of pigment, although other factorsmay substantiallyaffect the rate acertain Prince Ferdinand in the nineteenth century, it is worth of colour loss. See Saundersand Kirby1994 (cited in note 40). noting thatthe visitors’ book at Cava records thatFerdinand, Duke 45 This must remain purelyspeculative until analysis of the Rouen of Württemberg,visited the Badia in 1825; Ferdinand II, King of panel is undertaken. the TwoSicilies, in 1844; and Ferdinand Maximilian, the Archduke

FIG.35Pietro Perugino, TheBaptism of Christ, c.1497. Oil on wood, 39 × 68 cm. Rouen, Musée des Beaux-Arts, inv. 803-35.

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