“This period he can picture. If he saunters down to the Thames after his mid-day meal he will see this scene: merchants’ houses, wharves, the unloading of ships. But…the scale, the insatiable demand. The report states bluntly: the golden age at Venice, the Florence of the Medicis. English wool! Flemish cloth! London, Ghent, Lille….the market squares and tiered and jetted merchants’ houses. Dripping wealth, he thinks, and alum shipped as ballast! Under the lighter, more precious goods, alum. Alum – essential to the Venetian dyers, the Florentine tailors.”

Extract from ‘The Alum Maker’s Secret’