Archaeologists working at the ancient city of Oxyrhynchus in Egypt have unearthed a mummy with a passage from Homer’s “Iliad” stuck to its abdomen, in a first-of-its-kind discovery.

Most people probably aren’t itching to take a whiff of the mummified remains of the long dead. But doing so can unlock new pieces of the past, according to a new study. “Many people have sniffed ...