Potassium cyanide (KCN) was a crucial supply of alkali metallic cyanides before the invention of the Castner course of action. It had been made by the decomposition of potassium ferrocyanide. The reaction is as follows: KCN is used like a photographic fixer while in the wet plate collodion course of https://andyppmjf.thenerdsblog.com/36056974/are-cyanide-pills-real-secrets