How do you clean the drawer runners?

Rub a plain candle along the bottom edges. The wax fills the grain and reduces friction against the carcase. Avoid liquid oils. They'll soak into the timber and attract grit.

Why are some early chests in two halves?

Joiners built tall pieces in separate sections. Old house layouts featured tight corners and steep staircases that couldn't take a single large carcase. You'll usually spot a moulding wrapping around the middle to hide the join. Heavy iron carrying handles often remain fixed to the sides of each half.

I've inherited a large mahogany piece and the bottom drawer keeps sticking halfway out when I try to push it back in, how can I fix this?

The carcase has probably warped slightly, or the internal dust boards have shifted. When an antique chest of drawers settles on an uneven floor, the main frame twists just enough to pinch the sliding parts. Take the drawer right out and check for loose stops at the back. You'll sometimes find the small wooden blocks meant to halt the drawer get dislodged and wedge themselves along the runner.

We're looking for something to use in our modern bathroom, is a wooden chest of drawers going to warp with all the steam from the shower?

Prolonged humidity affects historic cabinetwork. Repeated cycles of steam and cooling cause carcase woods to swell, which forces veneers to lift and weakens old glue joints. Solid oak or pine examples handle damp conditions better than veneered mahogany. If you put one in a bathroom, ensure the room has a good fan and don't place it right next to the tub.