November in Sydney is all about the colour purple. Overhead, the jacarandas are in full bloom and, when the wind gusts through, many of those blooms are blown to the ground to form a soft purple carpet underfoot.
In the ancient and early medieval world, the dye known as “royal purple” was prepared from the secretions of the predatory Murex snail. The snail is still found in the shallow, coastal waters of the Mediterranean and its harvesting for the dyers’ “palate” has been documented to at least as far back as the Phoenicians. However, as between 10,000 and 12,000 murex were needed to produce one gram of purple dye, it was an expensive process and the resulting product was very highly prized. Thus purple became limited in its use to the preparation of cloth for the garments of the wealthiest in society. And it was a very short step from there to purple’s association with royalty. By the Middle Ages the “royal purple” was being replaced by (dark) blue as the royal colour of choice because of the difficulties in securing regular supplies of the murex purple.
With all of this in mind, I quite like the irony of seeing common garden snails inching their way across my backyard’s purple jacaranda carpet: this time, the snails are “on” the colour purple, not “in” it.