• To see if its possible to recreate the experiment below

Fascinating story on the BBC News website, about how retired engineer John Edmonds apparently has solved the mystery of obtaining Imperial purple.

"He explained to the British Association science festival in Salford, Greater Manchester, how he rediscovered the secret of imperial purple after studying the fermentation process of indigo pigments from the woad plant. "

Originally Murex was used, but the common cockle is related. John Edmonds bought a jar of them from the supermarket and removed the vinegar. He then put several of the cockles with some of the purple pigment in a 2 lb jam jar."

"Adding wood ash to the vat to ensure the mixture did not turn acidic, the mixture was then kept at 50 Celsius for about 10 days. "

"Wool dipped in the pigment turned green at first but, eventually, in contact with light, it turned purple. "