Potash
- Caustic potash is the common name of sodium hydroxide (NaOH), although it does not contain potassium
Potash is the common name of potassium hydroxide (KOH), a substance that has been used since antiquity in the manufacture of glass and soap, and as a fertilizer.
The name comes from the English words pot and ash, referring to its discovery in the water-soluble fraction of wood ash.
The term has become somewhat ambiguous due to the substitution in fertilizers of cheaper potassium salts such as potassium chloride (KCl) or potassium oxide (K2O), to which the same common name is now sometimes also applied.
The element potassium derives its English name from potash.
