Part 1 of 5 · freeIntroduction
Purple was the most expensive color in the ancient world. Royal purple, imperial purple: it edged the toga of Roman senators, then became so restricted that wearing it could cost you your life. It came out of a sea snail, the murex, gathered off the coast of Tyre in Phoenicia, on the shore of modern Lebanon. That city gave the color its name.
The chemistry comes down to one molecule. Take indigo, the blue of denim, and attach two atoms of bromine. That is the whole difference between the cheapest dye in history and the most costly. Because to get the purple out of the animal, you need thousands of snails for a few grams of dye.
The rest is in the Sophia app.The remaining parts, the open-book quiz and the full glossary. Free to start; Premium unlocks everything.
- 2A color reserved for emperors
- 3Twelve thousand snails for a hem
- 4One snail, many purples
- 5From the dye vat to the transistor
Open-book quiz8 questions whose answers are in the text.
Glossary7 terms explained in a tap.
30 languagesThe same course, from French to Japanese.
