Just bought an 1890 two-story brick house with a stone foundation.
The basement is dirt right now, and I'd like to pour a concrete slab
down there. There's sufficient cieling height for a 4" slab without
excavating, which I'd definitely prefer not to do. Do I need a vapor
barrier? Can I just pour right over the dirt? I'm just starting to
do my research, so any thoughts or info would be appreciated.

JP