Potash… an odd word, isn’t it? This material came from cleared forests, turned into ashes and then boiled in large cauldrons. That’s where its name comes from, inherited from the English words pot and ash.

In the mid-19th century, it was a true windfall: a barrel sold for as much as 10 pounds sterling! From Montréal’s warehouses, it was exported in huge quantities to Great Britain. This product was used in the bleaching and dyeing of textiles, as well as in the production of glass and ceramics, where demand was exploding.

In 1827–1828, Jean Bouthillier and his son Louis-Tancrède had three large warehouses built on land belonging to the Grey Nuns, to be used for inspecting potash—a highly sought-after product at the time. But the main purpose of these buildings’ soon shifted to the storage of export goods. In 1845, the merchant Louis Renaud stored grain and flour there. Two centuries later, these sturdy stone buildings now house offices and a restaurant, living witnesses to the transformation of Old Montréal.