One of the most bizarre uses of plutonium imaginable, is described in this patent from 1951, in which plutonium salts are used in “carroting” animal fur fibres to produce fine felt for gentlemen’s hats: Improvements In Or Relating To The Treatment Of Animal Fur Fibres (1951). Originally mercury salts would have been used and the poisonous effects of the use of mercury in hat-making has been personified in Lewis Carroll’s Mad Hatter character. What would he have made of plutonium?