Question: The explosive substance used by Andrew Kehoe was discontinued for farm use in what year?
Sentence (from "Aluminium sulfacetate"): Empyreuma is an obsolete chemical and medical term referring to "the smell and taste associated with burning vegetable and animal matter", and likely results in this case from the use of pyroligneous acid (wood acid) or wood acid lime in the preparation of the mordant.
Relevant evidence: No