Cities … do not last. The first was founded but ten thousand years ago, and many have come and gone since then. Sometimes, the sole evidence of their passing lies in evolution. Fourteenth-century Africa had a culture based on copper, mined from the deposits – still the largest in the world – of what is now the Congo and Zambia. Around today’s mines and smelters the soil is so full of metal that only plants with genes for tolerance can survive. One, the copper flower, grows in dense violet clumps on the most polluted soils of all.
Patches of that plant are found far from any habitation. They are the tombstones of lost villages, the remnants of a forgotten Industrial Revolution. Hundreds of copper crosses, used as money by the miners, are buried beneath the violet blooms. The genes of the copper flower are monuments to those who made the coins: all else has disappeared. They are a reminder of how fleeting are the wishes and efforts of man, how short his time, and in consequence how poor his products, compared with those accumulated by Nature during whole geological periods.