1. In this historical process, potassium cyanide was produced by decomposing potassium ferrocyanide : 2. Potassium ferrocyanide is a compound that includes small quantities of cyanide, a deadly poison.3. Potassium ferrocyanide contains small quantities of cyanide, a deadly poison.4. But defense lawyer Domenico Martelli argued that the compound _ potassium ferrocyanide _ is harmless. 5. The substance, potassium ferrocyanide , is not in itself dangerous, and is commonly used in gardening. 6. In addition, it can be produced by reacting mercuric sulfate with potassium ferrocyanide in water: 7. Potassium ferrocyanide contains small quantities of deadly cyanide.8. They alleged that the chemical compound _ potassium ferrocyanide _ was harmless in the quantities seized. 9. Chief Prosecutor Salvatore Vecchione said the substance, which was undergoing analysis, appeared to be potassium ferrocyanide . 10. Officials have said, however, that the substance _ potassium ferrocyanide _ didn't have enough cyanide to cause major damage.