Historical clue formulations

• Fertilizer ingredient — 2018-10-27
• Soapmaking stuff — 2010-02-02
• White, granular powder — 2008-10-23
• K2CO3 — 2001-10-20
• Soap ingredient — 2000-07-11
• K compound — 1997-10-30
• White, granular powder — 1997-06-12