I think it's pretty unlikely that I'll write a historical anytime soon. It seems like the kind of thing that would make someone like me become completely obsessed. I can picture myself spending a month researching the proper types of silverware for a throwaway line in a single scene. That said, I stumbled across a reference to Scheele's Green today and thought, wow, I wonder how I could use that?
Scheele's Green was a pigment used in wallpaper in the 1700 and early 1800s, and it contained arsenic. In a damp climate, a mold could grow on the wallpaper and release toxic arsenic gas into the air. It's a really creepy idea. One modern study says that the gas wouldn't have been strong enough to actually kill people, but still, what a fun plot twist for a Regency murder mystery.