The Alchemy of Color and Chemical Change in Medieval Manuscripts
About this video
Medieval manuscript painters made many of their brightest colours through alchemy, the experimental forerunner of chemistry, by causing chemical reactions such as heating sulfur with mercury to make vermilion. The video also shows that pigments keep changing chemically over centuries, and that modern chemistry helps museums identify, protect and sometimes restore these colours.
You'll be able to
- explain how medieval paint was made from powdered pigment and a liquid binder.
- describe how pigments such as vermilion, mosaic gold, verdigris and lead white were made through chemical change.
- give reasons why pigments can fade, darken or corrode over time.
- explain how modern chemistry helps museums preserve and understand medieval colours.
Key words
- pigment
- A coloured material, ground into powder, that gives paint its colour.
- binder
- The liquid that holds pigment powder together so it can be painted and stick to a surface.
- alchemy
- An experimental practice before modern chemistry that explored how materials interact and transform.
- vermilion
- A brilliant red pigment made by heating sulfur and mercury until they react.
- verdigris
- A green pigment made by exposing copper to fumes of vinegar, wine or urine.
- illumination
- A painted decoration or picture in a handmade manuscript.
Transcript
[MUSIC PLAYING] Medieval manuscript artists typically made paint from colored materials ground into powder and mixed with a liquid binder. Many of the most brilliant pigments didn't come straight from nature but were made through alchemy, an experimental practice that predates modern chemistry.
Beyond trying to change base metals into gold, the alchemists explored how materials interacted and transformed. Discovering paint colors was a practical outcome. Alchemy embraced astrology, medicine, philosophy, and mysticism. And within those contexts, colors had specific meanings.
A brilliant red, vermilion, was associated with chemical change and with alchemy itself. Producing vermilion involved combining two elements, sulfur and mercury, mixed and heated until a chemical reaction occurred. When ground into powder, vermilion turns deep red.
Many other vibrant pigments result from chemical transformations-- mosaic gold, produced by fusing tin and sulfur in the presence of mercury; verdigris, made by exposing copper to fumes of vinegar, wine, or even urine; and lead white, made in a process similar to verdigris but with lead.
Chemical transformation doesn't just happen when a color is born. It can occur throughout the life of a pigment, even centuries later, and museum researchers study it. The vivid colors of illuminations are often preserved because books are typically kept closed.
But sometimes, books are left open and their pigments can fade from exposure to light. Some colors darken from exposure to atmospheric conditions, others corrode. Verdigris can actually destroy the parchment or paper it's painted on. Today, chemistry deepens our knowledge about paint colors, their identification, and potential transformations.
Museums take preventative measures by controlling an artwork's environment and exposure to light. Sometimes, an original color can be restored as long as this is done carefully. By analyzing the chemical nature of materials, scientists can visualize how a pigment may have looked when it was first created.
Chemistry also reveals the astonishing knowledge that medieval alchemists and painters brought to working with color.
Video © Khan Academy, used under CC BY-NC-SA. Watch on Khan Academy. Puzzicle is not affiliated with Khan Academy.