Sifting through the debris of an 18th-century townhouse being renovated in Annapolis last month, the archaeologist and his students found what they were looking for under the brick floor near the kitchen hearth.

There, in a shallow five-inch pit, lay eight bent nails, a clear glass spindle, a plate of glass etched with a checkerboard design and a white pierced disk the size of a 50-cent piece.

What University of Maryland archaeologist Mark Leone and his team of students had discovered was evidence of hoodoo, a New World variant of ancient West African mystical traditions carried across the Atlantic by black slaves.

The practice, meant to influence healing and ward off misfortune, was continued well into the 20th century by freed descendants who lived and worked in the homes of wealthy white families as cooks, launderers and gardeners.

But Leone's research in Annapolis has raised an intriguing question: Scholars have yet to find hoodoo artifacts in homes owned and rented by the city's emerging black middle class in the 19th and early 20th centuries. In other words, while poorer blacks were keeping hoodoo alive, upwardly mobile African Americans were abandoning it.

"That's not to say that middle-class African Americans were giving up their African traditions, but they were finding different ways to express it," said Leone, who has led much of the research in Annapolis for the past 25 years,

The findings released last week add to the complex picture of black life in Annapolis and throughout the region in the decades before and after emancipation.

Hoodoo, which is practiced today, was widespread throughout the antebellum South.

Like other African-derived folk practices such as Santeria in Cuba and voodoo in Haiti, it mixed elements of Christianity with conjuring rituals involving herbs, dolls, pins and other everyday items bundled together as mojos worn on the body or buried in and around homes.

Frowned upon by Christian slave owners and later by white employers, the rituals were often conducted in secret -- what many scholars now see as a form of cultural resistance.

"In part you're talking about a sense of power and control," said Charles L. Perdue, who teaches folklore at the University of Virginia. "When you have no control over your destiny at all, anything you can do to increase the notion that you can exercise some power over your environment is a benefit to your psychic health."

Leone found the first inklings of hoodoo in Annapolis during an excavation in the early 1990s of the Charles Carroll House, home to a signer of the Declaration of Independence who had vast slave holdings.

Buried in a shallow pit in the northeast corner of the house were crystals, shards of glass, beads and a polished black stone. Researchers then didn't understand their meaning or why it appeared that the objects had been placed deliberately in the northeast corner.

The find drew the attention of Frederick Lamp, then curator of African art at the Baltimore Museum of Art. He suggested the materials might be a kind of nkisi, a grouping of religious artifacts used in religious rituals by the BaKongo people of West Africa.

Subsequent finds in Annapolis were unearthed in the Brice and Slayton mansions and, just last month, the Adams-Kilty House on Charles Street. The earliest materials date to 1790 and the latest to 1920.

Based on the oral narratives of former slaves, African American folklore and studies of West African rituals, researchers theorize that the ritual bundles -- variously called mojos, tobys or "hands" -- contain three key elements:

The first is something to catch and hold the spirit in place. In the Adams-Kilty cache, it was a piece of glass with a checkerboard design. The glass is transparent and looks like ash or water, mimicking the environment spirits travel in, Leone said.

Another element is something that belongs to the person to be affected by the spirit. This latest cache didn't appear to have such an object. Leone theorizes that it might have been the cloth, which disintegrated, used to wrap the cache. In the Brice house, the cache included a button engraved with the letter M, possibly belonging to a member of the Martin family, which owned the home in the late 19th or early 20th century, Leone said.

The third element is something that relates to the problem to be solved. In the Adams-Kilty case, it was probably the bent nails, which might signify arthritis.

Researchers have also learned exactly where to look: Under thresholds, hearths and stairwells -- places spirits were believed to congregate and use as entry points, Leone said. Another common location is beneath the northeast corners of houses, but the reason for that placement remains a mystery, scholars say.

During the same period they were excavating the homes of wealthy white families, researchers conducted digs at a half-dozen homes owned or rented in the 19th and 20th centuries by middle-class African Americans. They included the historic Maynard-Burgess House, home to John Maynard, a free black man born in 1810 who later bought his wife and stepdaughter out of slavery.

Maynard was part of a black middle class that began emerging around the 1830s, buying property and working as carpenters and waiters and running their own businesses.

Leone said the lack of evidence of hoodoo may reflect "the difficult choices facing African Americans who strived for acceptance and advancement, but wanted to remain connected to their traditions."

Swarthmore College religion professor Yvonne P. Chireau, author of "Black Magic: Religion and the African American Conjuring Tradition," said she isn't surprised by Leone's findings.

"There was a real split among black folks after the Civil War," she said, "in terms of whether they should abandon these traditions . . . and [move toward] what's called an ideology of racial uplift -- an emerging middle class joining American society."

Still, she predicted that further study would reveal pockets where even middle class blacks clung to elements of the practice, particularly when it came to health.

The move away from folk traditions is not unusual as groups move from one economic class to another, said Perdue of U-Va.

"Obviously when you have some money, you have some control," Perdue said. "Of course, you still had racism to deal with, but you would inevitably developed some ability to control your future."

The hoodoo cache found in the Adams-Kilty House includes a pierced white disk, glass etched with a checkerboard pattern, a clear glass spindle, a red-glazed pottery fragment and an earthenware handle.