Alum in Ancient Egypt
The ancient civilisations of Mesopotamia – modern day Iraq- used alum to fix the red dye madder to textiles. They imported this alum, known as “allaharum” in large quantities from Egypt. There is evidence of this process and trade dating back to before 2000BC.
The Egyptians mined alum as a naturally occuring mineral in the oases of Dakhla and Kharga, in the desert west of the River Nile and the landscape is honeycombed with ancient mines. The Egyptians did not start to use alum themselves until around the time of Tutankhamen, roughly 1000 years later. They would use it to fix dye to fabric, in glass making, glazing of ceramics, as well as in trade with the Greek and Roman empires.
When the temple of Delphi was destroyed in 545 BC large quantities of alum were sent to Delphi to be sold and help with the repair of this important sanctuary.
Alum in China
In China the study and practice of alchemy was combined with medicine, metallurgy, astronomy, botany and chemistry. Alum was an essential part of the Chinese alchemist’s laboratory. For some alchemists alum was a magical ingredient that could be used in the brewing of an elixir, or the transformation of metals. For others it was a dangerous distraction from the true path.
Methods for preparing the elixir of life which are known to be wrong or dangerous, but which are popular among the people.
Boiling the ash obtained from burning mulberry wood.
Mixing common salt, ammonium chloride and urine and evaporating to dryness.
Digesting saltpetre and quartz for a long time in a gourd and using the product.
Boiling saltpetre and blue-green rock salt in water.
Making and egg-shaped container of silver to hold cinnabar, mercury and alum.
Using iron rust and copper as ingredients for an elixir called ‘golden flower’.
Heating mercury together with malachite and azurite.
Heating realgar and orpient.
Heating black lead with silver.
Burning together dried dung and wax.
Some alchemists have heated sulphur together with realgar, saltpetre and honey, with the result that their hands and faces have been scorched, and even their houses burnt down.”
Chen Yuan Miao Tao Yao Lueh (8th or 9th Century)
Alum in Ancient Rome
The Romans used alum both as a mordant – to fix dye to cloth – and in the preserving of leather. The colours used in clothing reflected the status of the owner and the depth of colour and colourfastness was important. Throughout this time dyeing was a secretive business, methods often being passed down from father to son.
The Romans had a specific word – aluta – for leathers preserved with alum and alutarii for people who produced it. As this leather is not very water resistant it was usually only used for decorative purposes as it produces a white leather that is able to take colour well.
Alum also played a key role in medicine at the time. Dioscorides, a surgeon for the Roman Army, wrote all about the uses for alum and other medicines in his book “De Materia Medica”, written around 70AD. This book detailed the uses for over 600 herbs and remained in use for the next 1600 years.
Alum in the Middle Ages
During the Middle Ages there was an increased interest in Alchemy. Alchemy, a mixture of science and religion, had the aim of turning base metal into gold, the one pure metal. In order to achieve this a “Philosopher’s Stone” had to be created. Many methods to create this have been recorded in old writings but alchemists felt that ownership shouldn’t fall into the wrong hands so descriptions were deliberately vague or missing a key point in the process.
Once the Philosopher’s Stone had been created, alchemists believed it could be added to lead to make gold or used to create an elixir of life. This liquid once drunk would then give someone everlasting youth or immortality.
In order to create the Philosopher’s Stone many experiments were carried out and the foundations of modern chemical practices were formulated.
During the Middle Ages the study of science and nature underwent a renewed interest and many important works were written. This included “De re metallica” – On the Nature of Metals (minerals) by Georgius Agricola in 1556. In this book he described in great detail the method for mining and processing many metals and minerals including alum. His work remained the foremost text on the subject for the next 180 years.
Early Searches for Alum in Britain
Until 1453 much of the alum used across Europe came from the Middle East as well as the Greek islands of Lesbos and Milos. One of the main trading points for alum was Constantinople (modern day Istanbul) but all this changed with the fall of Constantinople to the Ottoman Turks.
After the fall many of the residents left the city and fled to other parts of Europe. One of these, John de Castro (the son of a textile agent in Constantinople), took to the Pope (Nicholas V) the secret of alum making. In 1461 alunite was discovered at Tolfa, in the papal states of Rome, and was quickly exploited as a virtual papal monopoly. In 1463 4 mines employed 8000 men.
During the reign of Henry VIII, a search was begun in Britain for a local, reliable and cheaper source of alum. Searches continued into the reign of Queen Elizabeth I across Britain and Ireland. Many searches took place and some resulted in leases from the Crown. In 1562 William Kendall was given exclusive rights for twenty years to mine alum across much of the West Country. The name of Alum Bay on the Isle of Wight, and Alum Rock in the Midlands, are thought to be as a result of this search, although there is no evidence that any alum was produced there. It was not until the early 1600s that alum was produced in Britain.
Birth of a Native Industry
Thomas Chaloner – owner of the Gisborough Estates – visited the Tolfa region of Italy in about 1600. Whilst there he visited the Papal alum quarries and, it is thought that he recognised the rocks as being similar to those on his estates in Yorkshire. From this observation, Chaloner realised that he may be able to make alum, the mineral long sought by a succession of monarchs, right here in England.
Legend has it that Chaloner then ‘persuaded’ a couple of alum workers to abscond with him. In one of the country’s earliest examples of industrial espionage, he is said to have secreted them in barrels, loaded them onto his boat and sailed home with the alum maker’s secret. When the pope learned of the English gentleman’s deception, he cursed Chaloner, his family, its future ventures and his descendents forever.
Once back in England, and after a good deal of trial and error adapting to the local rock, Britain’s first alum works commenced production, it is thought, at Spring Bank, Slapewath, on the land overseen by John Atherton, owner of the Skelton Estates.
In the wake of this success more works were founded at Newgate Bank (near Slapewath) before the industry spread along the coast and hills of North Yorkshire. Thomas Chaloner was credited with being the first person to produce alum in Britain and was awarded a pension from the Crown in recognition.