Blue-noses

“‘Pray, sir,ʹ said one of my fellow-passengers, ‘can you tell me the reason why the Nova Scotians are called “Blue-noses”?ʹ

“‘It is the name of a potato,ʹ said I, ‘which they produce in the greatest perfection, and boast to be the best in the world. The Americans have, in consequence, given them the nickname of Blue Noses.ʹ”—Haliburton: Sam Stick.