
William Notman, “Grey Nunnery, Youville Street, Montréal, QC” (detail), 1867, McCord Stewart Museum, I-26332.1.
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.