“We can learn to associate good things with ‘bad’ smells – if you smell a really ripe cheese on the London underground, that’s going to smell disgusting. But in a nice shop or at home, that smells delicious. We learn to attribute certain positive attachments to smells.” For one museum exhibition about the Roman empire, [Tasha] Marks created the scent of the purple tunics worn by the elite. The dye, Tyrian purple, was made from the mucus of a sea snail, “so when it got slightly wet, it would smell like fish, and that became a sign of excellence. It’s a learned response – this is the smell of luxury, this means expensive.”

— Read more in ‘There’s otter poo, dragon poo …’ The woman who can make you smell everything, from hell to your grandparents at The Guardian.