- / 1663 MURAL PAINTING IN SAN TARASIO CHAPEL IN THE CHURCH OF SAN ZACCARIA, VENICE: A STUDY OF THE STATE OF CONSERVATION OF PAINT FILM FASSINA, V., ROSSETTI, M., Soprintendenza ai Beni Artistici e Storici di Venezia ZUCCHETTA,E. Soprintendenza ai Beni Ambientali e Architettonici di Venezia SUMMARY In this paper some preliminary results on the state of conservation of mural painting and gilding, are presented. At the moment the restoration work is currently in progress. In order to obtain significative results the following analytical methodologies were used: - Observations of cross sections by using reflected and UV light microscopy, improved by chemical micro tests showing qualitatively the presence of organic compounds. - Observations by Scanning Electron Microscopy (SEM) improved by microprobe Energy Dispersive Spectrometer analysis (EDS). - Ion Chromatography analysis of water soluble anions. First of all the pigments forming the colour layers were characterised. As regards the paint film it presented some different state of conservation: in fact in some areas, surface appeared very bright, and in other one it showed a whitening effect. The whitening and brightening effects could be ascribed to previous treatments carried out in different time in the past. During the current restoration work some problems of cleaning were met due to the difficulty to remove the treatment substance without damaging the paint film. According to our hypothesis the substance used during the most recent restoration intervention, probably interact with the paint film so causing a difficulty to remove decay products generated by this interaction without damaging paint film. In other areas there are gilding with different feature: the results of analysis showed two kind of gilding, one containing a gold lamina and another one with tin and gold. The latter was found in different areas. Gypsum due to sulphation of calcite is sometimes present on red scialbatura of bricks and on painted surface 2. HISTORICAL BACKGROUND AND INTRODUCTION The frescoes in the Chapel of San Tarasio, formerly the apse of the old Church of San Zaccaria, constitute one of those fortunate instances where the artist (or in this case two artists) actually signed the work in question, so attribution poses no problem. The frescoes, depicting St. John the Baptist, the four Evangelists, Luke, Mark, John and Matthew, St. Zacharias and God the Father, bear the names of Andrea da Firenze (identified by Fiacco in 1920 as Andrea del Castagna) and an assistant, a certain Francesco da Faenza; the inscription also gives the date as August 1442. The very fact that two artists were involved, however, raises the thorny problem of identification of their separate contributions, though there can be no doubt that the organic and harmonious nature of the whole means that the overall design must be the work of Andrea, while Francesco da Faenza, whose name also appears below that of Andrea, will have been responsible for translating at least some of his more famous companion's drawings into their final form. One way of distinguishing between the two artists' work might be to attribute to Francesco da Faenza the less accomplished parts of the cycle: some of the less assured winged putti on the intrados of the arch framing the apse, for example, though these too have something definitely Castagnesque about them. Fiocco's attribution of the minor sections of the San Zaccaria frescoes to the mosaicist Silvestro, known to have executed the two mosaic depictions of St. Anthony Abbot and St. Vincent Ferrer in the right transept of St. Mark's Basilica in 1458, now seems less than convincing. It is more logical to think of Francesco da Faenza as responsible for the figure of St. Mark, the painting of which betrays a certain immaturity and superficiality, while Andrea must have painted God the Father, crowned and seated among clouds, his hand raised in blessing; the breadth of the head is typical of 1664 Andrea's later work, and the solemn expression on the face seems clearly to derive from Byzantine depictions of Christ Pantocrator. The three red-winged cherubs at the top of the mandorla are certainly by Andrea, while the other three, lower down among the clouds, are by a less expert hand, pemaps that of Francesco da Faenza. The St. John the Evangelist, however, constitutes a real problem of attribution since it is painted quite differently from the other figures with the shot effect of their garments and the plastic vigour achieved through contrasts of light and colour. The figure is infused with colour and bathed in daylight almost redolent of Piero della Francesca; the stance is meditative and the Saint has a red book under his arm: in view of these characteristics, most critics are of the opinion that it was painted by Domenico Veneziano. Formal considerations again prevail over chromatic values in some of the figures in the intrados of the arch, but they are not sustained by the almost atmospheric effect discernible in the St. John. The San Tarasio St. Luke may have engaged both Francesco and Andrea, a certain angularity in the folds of the cloak being traceable to the latter, while the forced realism in the figure's fixed gaze and the awkwardness of the arm both suggest the hand of Francesco. St. Zacharias can safely be attributed to Andrea, the severe facial expression suggesting the influence of Cimabue and of Donatello's statues of prophets in the campanile of the Duomo in Florence. In the last two segments of the fresco, on the right, Francesco probably painted the scrolls and Andrea the two seraphs. On the intrados of the arch, ten winged putti, painted in various attitudes, support the weight of ten tondi containing busts of prophets and saints. We may reasonably suppose that Andrea had accepted a commission to decorate not only the apse but also the ceiling and walls of the presbytery (apart from the side niches, the San Zaccaria chapel is similar to the Ovetari Chapel at the Church of the Eremitani in Padua), probably with a series of stories of St Zacharias and St. John the Baptist, from Gabriel's announcement to the prophet of John's birth, through various episodes in the saint's life to his death and burial, with the four panels of the cross vault would probably have been frescoed with depictions of the Doctors of the Church. We can only surmise such a development, however, because for some reason Andrea's scheduled work in Venice was interrupted and the city's only examples of his tormented and rugged art are the frescoes in the apse of the chapel. Previous restorations Andrea del Castagno's frescoes have been the subject of conservation work at least since the middle of the XIX Century. Research is still going on at the Venetian State Archives into the precise nature of the work done around 1850, but it is already clear that damp and inadequate maintenance. as usual in Venice, were the main causes of the frescoes' extremely poor condition at the time. Attempts were made to consolidate the frescoed panels and ribs of the apse using repeated applications of beverone di caseina and emulsified oils to fix the paint. The restorers also carried out a certain amount of repainting and retouching, especially on the blue background. Renewed attempts to consolidate the paint were probably made later using other fixatives and varnishes. In 1893, Pietro Paoletti reported the fall of a section of fresco three years before and in 1915 Laudedeo Testi confirmed the continuing poor state of what he described as Andrea da Murano's work as "much blackened, crumbling and generally in very bad condition". Not long after, in 1923, Carlo Gamba , writing in "Dedalo" about "a previously unrecognised work by Andrea del Castagna", complained that further restoration of the paintings was still not finished. We have no documentation of the work carried out in the 1920s, but it evidently failed to stabilize the condition of the frescoes if in 1949 Muraro writes that they once again required radical attention. A few years later, in 1955, they were still in appalling condition but now that their high quality was recognized (in 1920 a layer of whitewash was removed to reveal the cartouche containing the name "Andreas de Floretia", whom Fiacco identified as Andrea del Castagna) Mario Salmi urged yet another restoration, directed mainly at cleaning what was described as the "extremely darkened" 1665 surface. Salmi's recommendations were promptly acted upon by the then Superintendent for Monuments of the Veneto, Antonio Rusconi. At the time, before work started, it seemed apparent that no lasting results could be achieved if the conservation operations had once again to be carried out in situ. M. Muraro, then an Inspector for the Superintendency, was in favour of radical action rather than the constant "drip" of partial efforts which brought only temporary solutions. Muraro's attitude was by no means innovative, however, for as long ago as 1863 Cavalcaselle had proposed similar vigorous action, otherwise the tremendous damage arising from the damp would certainly result in "the loss of the paintingsj. All the arguments were put to the Supreme Council for Antiquities and Fine Arts, appointed by the Ministry to decide exactly what should be done. Fortunately, it was decided to reject Muraro's suggestion that the frescoes should be detached, a conservation technique which was much more freely used in those days than is now believed to be necessary or wise; instead, the Council adopted the more reasonable proposal of another in situ restoration. Work was carried out by Leonetto Tintori of Prato and Alfio del Serra under the supervision of the Supreme Council itself and was completed in October 1956.