The Ford family's favorite heirloom is small, brown and hard as a rock. It smells funny—like moldy rum—and it wouldn't sell for much, if anything. "After you've seen it a couple times," admits Dorothy Ford, who dusts it periodically, "it isn't anything special." It is, however, almost surely one of a kind, and the Fords take pride in that. Their heirloom is a 109-year-old fruitcake.

Like many an ancient treasure, this one comes with a story. Late in 1878 Fidelia Ford, 66, a Berkey, Ohio, farmer's wife, baked her customary holiday fruitcake and set it aside to age until the following Thanksgiving. But Fidelia died before the big day rolled around, and her family hadn't the heart to consume her handiwork without her. They felt that way the next year too, and the next, until, instead of a mere dessert, the Fords had a legacy on their hands.

Today's custodians of the cake are Morgan Ford, 67, a retired mechanical engineer, and his wife, Dorothy, 59; they inherited the edible artifact 35 years ago from Morgan's dad, Lyman, Fidelia's grandson. The cake resides in a glass compote dish in a china cabinet in the Fords' Tecumseh, Mich., home, sometimes appearing as a dining-table centerpiece on holidays. Morgan and Dorothy's granddaughter, Sarah, 8, finds the cake totally "yucky," but older relatives show more respect. "We joke that we have a 100-year-old fruitcake in the family, and it's not my father," says Sarah's mother, Sue Durkee. "But it's a tie to the past, and it's neat to have." Says her brother, Jim, who is the fruitcake's heir apparent: "When I was growing up, I didn't even tell my best friend about it. Now I feel proud."

Only once in this century has the heirloom's peaceful existence been threatened. One day in 1966, Morgan's Uncle Amos, 86—two years younger than the fruitcake—came over with a peculiar look in his eye. Recalls Morgan: "He said, 'It's a dirty shame nobody ever tasted Grandma's cake—mind if'n I try it?' I thought he was kidding, because he was a joker. But he got out his jackknife and whittled off a piece. He chewed it a bit, and it sounded kinda crunchy. He never said a word."

Uncle Amos passed on two years later, still uncommunicative about the taste, but the Fords see no reason why the cake shouldn't go on forever. "Fidelia wasn't very good-looking—in fact, she was pretty homely," says Morgan. "But she sure knew how to bake a cake."