Dott. Nazareno Gabrielli, whose exploits range from directing conservation works in the Vatican, especially in the Sistine Chapel, to exhuming bodies of long-dead saints, was in Malta last week to deliver a lecture.

Dott. Gabrielli had been to Malta once before when he had assisted at the exhumation of the body of Saint George Preca (although the real expert’s work was done by Dr Abela Medici).

Exhumation of the bodies of saints is one of the tasks he has been undertaking as director of a scientific laboratory.

Prior to coming to Malta, he had directed the exhumation of the body of San Padre Pio, which involved, amid many controversies, no less than 50 days work.

He also exhumed the body of Pope John XXIII and that of San Ubaldo from the altar in which he was entombed for seven long centuries in Gubbio.

Dott. Gabrielli is the scientific consultant at St Peter’s Basilica in Rome and has been the director of the Laboratorio Scientifico dei Musei Vaticani for the past 35 years. He delivered a talk on “Applicazioni scientifiche nella conservazione dei dipinti murali: La Cappella Sistina e gli affreschi di Michelangelo” at the church of Santa Caterina d’Italia in Valletta last Wednesday.

The talk coincided with the inauguration of the restored Mattia Preti masterpiece The Martyrdom of St Catherine, which the artist had presented to the Knights of the Italian langue as an altarpiece for the Church of St Catherine, adjoining the Auberge d’Italie in Valletta, to manifest his desire to be raised in rank within the Order.

On the occasion of the 30th anniversary of its founding, the National Student Travel Foundation (Malta) has carried out the restoration of the Preti masterpiece. It was responsible for Dr Gabrielli’s visit and lecture as part of the Educational Project associated with this restoration.

This restoration work has been dutifully and expertly completed by the firm Sante Guido Restauro e Conservazione di Opere d’Arte under the direction of Sante Guido and Giuseppe Mantella.

Dott. Gabrielli was directly involved in the cleaning of the Sistine Chapel between 1981 and 1984 funded by the owners of a Tokyo paper and the second television channel in Japan, NTV.

That proved quite controversial because many people saw the result as too brilliant and colourful as they thought that the original Michelangelo works must have been as dark as they had always seen them. But then it turned out that the paintings had been darkened by centuries of burning candles, as well as braziers in winter. It was this that gave the paintings the patina of darkness.

Dr Gabrielli’s work involves not just the Sistine Chapel but also the Vatican museums, which do not consist only of the Pinacotheca but also the various museums of archaeology and so many items, all of which require conservation and preservation.

Today’s art conservation has improved so much that is able to offer hitherto unobtainable details about how the original paintings were done. It has thus been possible to identify the pigments used by Michelangelo. Quite surprisingly, today’s experts agree that Michelangelo did not use as extensive palette of colours as the great Renaissance painters that came before him, from Botticelli to Pinturicchio.

The reason for this is that unlike 15th century artists, Michelangelo painted only on affresco, whereas they used tempera and glue. For this reason, it is easier to restore (or conserve) a Michelangelo affresco because the paint penetrates the affresco whereas with the other painters the original paint is very thin and, once removed, cannot be restored.

Apart from Michelangelo, there is only one 16th century artist who comes close to the artists of the previous century in the vast range of colours he used – and that is Raffaello. But that is because Raffaello used his own special technique: he waited until the basis of the painting began to dry and then painted rapidly, with just one stroke. His paintings are 12 microns thick (one millimetre = 1000 microns) whereas paintings by Michelangelo, for instance, can be up to 100 microns thick.

Michelangelo was quite restrained in the amount of colours he used, maybe because these were rather difficult to obtain. However, there could also be another reason: throughout his long life he remained a sculptor first and foremost. His first paintings have a rather sculptural approach and also show that he was still under the influence of the artists who preceded him, but then he came into his own in the glory that is the Sistine Chapel.

After the restoration of the Sistine Chapel, work is now proceeding on the next big restoration project: the Cappella Paolina, especially the two big paintings by Michelangelo: the Conversion of St Paul and the Crucifixion of St Peter.

The research done prior to the restoration of the Sistine Chapel also helped to shed more light on the structure of the chapel itself.

It seems that prior to the building of the Sistine Chapel there was a previous chapel, the Cappella Magna.

The whole structure of the Sistine Chapel was very precarious. The Swiss Guards had their own apartments on top of it and the greatest danger came when they were digging to lay the foundations of St Peter’s and the south wall of the Sistine Chapel threatened to collapse. To stave off disaster, they had to tie it round with great chains whose connecting points are still visible.

One consequence of this great instability is in the konsentura visible in the Holofernes painting. On Christmas Night 1522, when Pope Adrian VI was celebrating Midnight Mass, an architrave fell and killed a Swiss Guard and two paintings from the 15th century were damaged beyond repair. It was only when Vignola built walls around the chapel that the structure was made safer and steadier.

Any discussion on Michelangelo and the Sistine Chapel would be futile without mentioning the braghe and the braghettieri. The Counter-Reformation Church and the Vatican especially looked askance at the multitude of nudes in the most holy of papal chapels and no less than three different artists were brought in to clothe the nudes with sort of breeches, some of which are still there today.

The most curious case regards Daniele da Volterra, who was a friend of Michelangelo and only did a few braghe before he died on the very same day that Michelangelo died.