Copyright © The Malta Historical Society, 2005.

Source: Melita Historica : Journal of the Malta Historical Society. 1(1953)2(125-126)

[p.125] Restoration of Preti’s Paintings

Joseph Cassar Pullicino

For several years the Preti paintings in St. John’s Co-Cathedral have formed the subject of articles in the Press and of official statements in Parliament. It was with satisfaction, therefore, that art lovers in Malta received the news of Professor Cesare Brandi’s visit, in February 1952, to inspect, and advise on, the restoration of the paintings on the vault of St. John’s. Prof. Brandi is the Head of the Istituto Centrale del Restauro, and Supt. of Mediaeval and Modern Art in the Rome Sector. He enjoys an international reputation and is well known in art circles for his lectures on medieval and modern art. He has served on several international commissions for the restoration of works of art in Belgium, Austria and Yugoslavia, and has contributed several works of permanent value on the history of Art. Professor Brandi runs the review “L’Imagine,” and the Bulletin of the “Istituto Centrale del Restauro,”which latter publication is the only technical review of its kind dealing exclusively with problems relating to the restoration of works of art.

Professor Brandi’s visit focussed public interest on the subject of restoration work, with special reference to the paintings in St. John’s. An informative article appeared in the “Times of Malta” of the 26th March, 1952, written by its Art Correspondent who, basing himself mainly on an able study by Vzo. Bonello “I Restauri della Volta Pretiana in San Giovanni” (Archivum Melitense, Vol. VII, pp. 61-69) outlined the history of these paintings. The writer stressed that the paintings were executed in a manner which appears to be unique. “On account of the porous texture of the limestone of which the Church is built, the artist decided at once to paint directly on the stone in oils and not in fresco, as he would certainly have done on any other surface. For this purpose the Special Commission appointed to report on Mattia Preti’s offer to cover the vault with scenes from the life of St. John recommended that he was to be supplied with all the oil he required... The stone was soaked in linseed oil with sponges and then the painting was executed in oils over this priming. The aim was not only to avoid the cracking, flaking and other ills to which frescoes are subject, but also to get over the difficulty of having to plane down the surface of the stone, which would have been fatal, as it is characteristic of the local limestone that it won’t stand being dressed a second time with metal tools once it has been exposed to the air.”

After a short description of the way in which the Preti paintings were restored, or rather totally repainted, by Ignazio Cortis in the 1860’s, the writer passed on to mention how in 1923 Chev. Vzo. Bonello, in the above quoted paper, revealed that “on closely examining the ceiling, he had discovered that what had appeared in 1860 to be the bare stone of the vault was in reality nothing but a discoloration caused by water seeping through the stone and producing a salt similar to nitrate of potassium which spread over the colour in large white patches. When some of the salt was removed it was found that the colour was still intact underneath, so that the “restorations” of the 1860’s had not even been necessary. Chev. Bonello also said that, in consultation with Sir Temistocles Zammit and Prof. A.A. Sultana, he had succeeded.not only in freeing large areas of the paintings from the salt but also [p.126] in reviving and fixing the colours themselves with a solution of linseed oil. Following this method, word proceeded apace till 1937.”

At the end of World War II, when blast damage had added to the Church more chronic ailments, Mr. C.H.M. Gould, Asst. Keeper of the National Gallery, came to Malta in July, 1949 and in the following year he submitted a report in which he suggested that, owing to the unique nature of the paintings, he doubted whether there was anyone in England who could help and suggested that the Malta Government should seek advice elsewhere. In February 1952, through the good offices the British Ambassador in Rome, Professor Brandi was invited to come to Malta and advise on the matter.

A copy of Professor Brandi’s report, which is still unpublished, may be perused at the Royal Malta Library. The report, which was summarised in the Times of Malta of the 13th and 15th May 1953, is in three parts: the first concerns the mural paintings by Mattia Preti; the second deals with the results of the extensive chemical research and analysis carried out on various samples taken from St. John’s, and the third is a detailed report on the state of preservation and suggestions for the restoration of Caravaggio’s masterpiece “The Beheading of St. John.”

In the main, Professor Brandi confirms Chev. Bonello’s observations made in 1923 and expresses the opinion that, “with the help of the extra iron roof recently constructed over St. John’s, which guarantees against further drenching by rains, it is safe to hope that when the stone of the ceiling is completely dried, it is unlikely, that the efflorescences will reappear once they have been removed.” He makes various other suggestions regarding the correct method to be followed in removing stains, the preservation of the original colour when it emerges after the cleaning, and the removal of the paintings executed all over the ceiling by Cortis between 1867 and 1874. Professor Brandi also recommends that scaffolding should be erected under at least half of the ceiling and that an extensive photographic reproduction of the paintings should be made to show the position and extent of Cortis’s retouchings.