Our clay walls are finished with limewash, a material proved over generations and continents. Shakespeare would not have glanced twice at it, nor would Ben Franklin. Lime is also used to keep dust down on roads, and to disinfect farmers’ fields. Limewash is “slaked” — hydrogenated in water — so it doesn’t burn skin.
Lime application is calcium carbonate, which is found in high concentrations in vegetables such as broccoli and kale. It is the material that makes seashells and eggshells. Lime becomes harder (and whiter) as the calcium hydroxide combines with the carbon dioxide in the air over time.