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Recovered crusts. A) Lesion crust material from Virginia, USA, photographed after gamma irradiation. Photograph by James Gathany. B) Lesion crust material from an envelope contained within a book, New Mexico, USA, nineteenth century. Photograph by Russell L. Regnery. C) Lesion crust material from a jar on display in a museum, Arkansas, USA. Photograph provided by Erin Goldman.
