Science: The Coin of the Realm

Explaining the fall of the Roman Empire has traditionally been left to philosophers and historians, who have variously placed the blame on wars, epidemics, social inequalities, indolence and overambition. More recently, specialists from other disciplines have taken their turn at scrutinizing Rome's downfall. A few years ago, a sociologist suggested that the empire had withered away after its upper classes died off from lead poisoning caused by lead-lined drinking and cooking vessels. Now a geochemist has concluded that Rome's troubles derived largely from the loss of its supply of silver, which fatally disrupted...