With the help of X-ray fluorescence it is possible to know the identity of the atoms that are part of a work of art and, in short, the periodic table used by the artist.
A curious legend circulates in the streets of Bristol that has its origin in the 18th century. It is said that one day William Watts, an English plumber, after a delirious drunkenness dreamed that spherical drops of lead rained from the bell tower of a church.
Several days later he passed this molten chemical element through a perforated zinc tray that was placed several meters from the ground. Fruit of the free fall spherical balls were formed that, little by little, cooled and eventually solidified in a bucket of water. In this peculiar way he invented the first lead pellets.
With this story, some of the most interesting properties of this element are revealed: it melts at a relatively low temperature (327ºC) and is easily molded. If we add to this its abundance in nature and its low cost, we already have all the ingredients to make it one of the chemical elements most related to art.
Leaded glass cages
We find lead in applications as disparate as the mobile types of printing presses, the manufacture of pipes or stained glass. Thanks to lead, some medieval churches, such as Parisian Saint Chapelle, became spectacular glass cages.
When we visit a Gothic cathedral, the prominence and beauty is given to the colored glass, but the soul of them, the true skeleton without which they would not exist, is lead. Leaded rods were one of the indispensable elements of the daily work of the master glassmakers, the other was the tin, with which they obtained the welds.
Lead was also the fatigue partner of another medieval artist, the illustrator. He used a reddish compound formed by lead oxide – the popular minio – to profusely decorate the manuscript initials and make his famous “miniatures.”
From albayalde to yellow from Naples
Lead has not gone unnoticed by sculptors of all ages, for example, it was one of the materials preferred by Pablo Gargallo. Due to its high density and malleability, he obtained large sculptures.
Lead has also given us a huge variety of pictorial pigments. One of the most important in history is the white albayalde. It was manufactured from lead carbonate through a curious manufacturing process known as the Dutch method.
First of all, special earthenware vessels were made arranged in two compartments connected and covered with a source of heat and manure (carbon dioxide). Vinegar was placed in the lower compartment and lead plates in the upper one, so that the acetic acid vapor was allowed to come into contact with the metal. A few weeks later a white crust appeared on the lead, which was removed, cleaned, dried and ground, obtaining the precious white pigment.
The first synthetic yellow in history became known as “Naples yellow” and was nothing other than lead antimony. It seems that it began to be used in the country of the pharaohs during the 18th dynasty but it was not until the 18th and 19th centuries when it reached its maximum splendor.
Unfortunately for painters, lead was not harmless, with many artists suffering from a professional illness known as saturnism, plumbosis or plombemia. In the list of affected painters are large swords such as Goya, Rubens, Fortuny, Van Gogh, Renoir, Frida Kahlo or Portinari.
Pedro Gargantilla is an internist at the Hospital de El Escorial (Madrid) and author of several popular books. .